Title: Author(s): Nicola Merluzzi, Huiyin Lee, Kuili Suganya, Iat … · 2020-05-29 · Author(s): Nicola Merluzzi, Huiyin Lee, Kuili Suganya, Iat Meng Wan Unit: SA7 Institution:

Erasmus Mundus

Programme:

ADVANCED MASTERS IN STRUCTURAL ANALYSIS OF MONUMENTS

AND HISTORICAL CONSTRUCTIONS

Consortium Institutions: UNIVERSITY OF MINHO, PORTUGAL

CZECH TECHNICAL UNIVERSITY IN PRAGUE, CZECH REPUBLIC

UNIVERSITY OF PADOVA, ITALY

TECHNICAL UNIVERSITY OF CATALONIA, SPAIN

Satellite Participant: INSTITUTE OF THEORETICAL AND APPLIED MECHANICS, CZECH REPUBLIC

Title: Integrated project - St. Torcato Church

Author(s): Nicola Merluzzi, Huiyin Lee, Kuili Suganya, Iat Meng Wan

Unit: SA7

Institution: UNIVERSITY OF MINHO

Date: March 14, 2008

St. Torcato Church

Erasmus Mundus Programme

ADVANCED MASTERS IN STRUCTURAL ANALYSIS OF MONUMENTS AND HISTORICAL CONSTRUCTIONS

2

TABLE OF CONTENTS 1. PROJECT BRIEF 4

1.1. Methodology 4 2. ST. TORCATO – INTRODUCTION 5

2.1. Location 5 2.2. Construction techniques and material 5 2.3. Tower description 5

3. DAMAGE SURVEY 6

3.1. Photomodeler 6 3.2. Defects typology 9 3.3. Analysis of the defects 10

3.3.1. Structural defects 10 3.3.2. Non structural defects 10

4. NON DESTRUCTIVE TEST 11

4.1. Standard penetration dynamic test – year 1998-99 12 4.2. Proposed NDT’s & MDT 12 4.3. Proposed other tests 14

5. MONITORING 14

5.1. Conclusions on the monitoring recordings –year 1998-99 15 5.2. Monitoring proposal and location 16

6. DYNAMIC IDENTIFICATION 21

6.1. Test planning and results 21 7. STRENGTHENING TECHNIQUES 26

7.1. First phase: Foundation strengthening 27 7.1.1. Subsurface conditions 27 7.1.2. Foundation strengthening technique 28 7.1.3. Micropile background 28 7.1.4. Design methodology 29 7.1.5. Introduction to piling machinery 29 7.1.6. Design and installation Data 30 7.1.7. Connection design 31 7.1.8. Installation specification 33

7.2. Second phase: Tie rods strengthening 33 7.2.1. Simplified verification 35 7.2.2. Limit analysis 39 7.2.2.1. First mechanism 40 7.2.2.2. Second mechanism 41 7.2.2.3. Third mechanism 42 7.2.2.4. Fourth mechanism - local 43 7.2.3. Strengthening design 43

7.3. F.E.M Model 48 7.4. Phase analysis 49 7.5. Truss support strengthening 58 7.6. Arches strengthening 60

8. RECOMMENDATION AND MAINTENANCE PLAN 62

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9. CONCLUSIONS 64 10. REFERENCES 66 ANNEX A – Conditions mapping 68

Observation on defects 68 Flooring cracks 68 Ceiling cracks 70 External walls cracks 71 Internal wall cracks 77

ANNEX B – Strengthening & Dynamic Identifications 79

Limit analysis calculations: overturning around base hinge-simplified approach 79 Limit analysis calculations: overturning around base hinge 80 Limit analysis calculations 81 Other possible failure mechanism after tie strengthening 83 Crack widths 84 Truss support strengthening 86 Dynamic identification 87 Sampling and acquisition 87

Left Tower (Bell Tower) 88 Right Tower 88 Front Façade 88

Diana Command files for phase analysis 89 ANNEX C – Specifications of the works 94

Specification for the strengthening of the foundations 94 Specification for the application of tie rods 98 Specification for the strengthening at the truss supports 100

ANNEX D – Bill of Quantities 102 ANNEX E – Drawings 103

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1. PROJECT BRIEF

S.Torcato church in St. Torcato village has a hybrid architectural style. This church is located about

7Kms north of Guimaraes, Portugal. This church is exhibiting severe structural problems. In the years

1998-99 there was a monitoring system installed and non destructive testing undertaken at the church

for condition assessment. Today the church authorities are planning for a strengthening of the church

under stress.

Present scenario:

From the last diagnosis report (Luis Ramos 1998-99) it is evident that the presence of the loose soil

towards the southern part of the church is creating settlements in two directions (N-S and E-W)

causing the tower to tilt and go out of plumb. This condition has caused severe cracks on the church.

The aim is to design a possible structural strengthening, to stabilize the cracks and

deformations.

1.1. Methodology

1. Visual inspection: A preliminary in-situ survey was carried out in order to understand the details

on the geometry of the structure and on the visible damages (cracks, out of plumb, material

decay) and also to identify the points where more accurate observations have to be concentrated.

2. Geometrical survey: By the use of Photomodeler software

3. Damage Survey

4. Non Destructive tests: NDT techniques can be useful for determining any one of the following

mentioned defects in the structure.

Detection of hidden structural elements, like floor structures, arches, pillars, etc.,

Qualification of masonry and of masonry materials, mapping of non-homogeneity of the

materials used in the walls (e.g. use of different bricks in the history of the building)

Evaluation of the extent of mechanical damage in cracked structures, detection of the

presence of voids and flaws, evaluation of moisture content and capillary rise, detection of

surface decay

Evaluation of Mechanical and physical properties of materials like mortar, brick and stone.

5. Design of a Monitoring system: Since vital crack patterns were found during the the preparation

of the previous report and since a progressive growth is suspected due to soil settlements, the

measure of displacements in the structure as function of time have to be collected. Monitoring

systems needs to be installed on the structure in order to follow this evolution.

6. Numerical modelling and Strengthening design:

The knowledge of the collapse mechanisms in the cases of non repaired and repaired state of

the structure would help to understand the reasons for some failures connect them to the

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construction and material characteristics and would help in arriving at more appropriate

retrofitting techniques.

7. Additional monitoring and maintenance plans

2. ST. TORCATO – INTRODUCTION

2.1. Location

The Church of St. Torcato is located in the village of St. Torcato, 7 km north from the city of

Guimarães. The church combines several architectonic styles, like Classic, Gothic, Renaisance and

Romantic. This “hybrid” style is also called in Portugal as “Neo-Manuelino”. The construction started in

1871 and still continues these days. The dimensions involved are significant: main nave has

57.5 × 17.5 m and 26.5m height; the transept has 37.1 × 11.4m; and the bell-towers have a cross

section equal to 7.5 × 6.3 m2 with, approximately, 50m height.

2.2. Construction techniques and material

The entire church is built in masonry with locally available natural granite stones and dry joints;

The wall is a three leaf composite wall;

The roof of the nave has a masonry vault ( Figure 2-1);

There is a wooden truss over the vault of the nave, which acts as a protection to the vault from

varied climatic conditions. (Figure 2-1);

The external elevation facing south has an entablature with a colonnade;

Doors and windows have arch openings (Figure 2-1).

Figure 2-1: Truss, rose window and arches

2.3. Tower description

The two towers are square in plan one each towards east and the west. The two towers are

connected by a rectangular bay, which acts as the main entrance to the church (see Figure 2-2). All

the openings of the tower are constructed out of arches. This main entrance façade facing south has a

rose window. Both the towers have stone staircase to reach till the top of the spire. The east tower

houses the church bell. The second and third level of the central rectangular bay is accessible by the

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Figure 2-2: South façade

tower stairs. The entablature colonnade, 0.65m wide, is accessible from

the roof of the third level. The second level central bay has a brick

masonry vault with stone ribs spanning east west. The third level has a

wooden truss and clay tile roof cover protecting the unfinished vault.

3. DAMAGE SURVEY

The first studies were based on visual inspections and empirical knowledge, and they were focus on

the following aspects of the material’s physical appearance, Leanings, Settlements, Deformations and

Crack pattern.

To better represent these pathologies, the creation of a 3D rendering of the all church has been

attempted and the results and problems are explained in the following paragraph.

3.1. Photomodeler

In order to have a countercheck with the in situ damage survey and a powerful tool to represent the

St. Torcato church, the software PhotoModeler® has been used.

PhotoModeler is used in the fields of architecture, engineering, construction and preservation in a

number of ways: to generate elevation drawings of existing buildings, to perform measurements of

structures, to get 3D outlines of one or more buildings for massing, sun or wind studies, and to extract

data from historical photographs. PhotoModeler can allow the professionist creating the 3D models of

the structures and measurements from photographs. It is a powerful tool especially for this latter task:

when a good quality photomodeler 3D render is implemented, the professionist can have easily

access in measuring dimensions, cracks or openings otherwise only possible with the use of

expensive scaffoldings, thus allowing easier surveying of existing structures and objects.

In fact, after the finalization of the 3D picture a high quality image can be obtained. This picture can be

rotated or scaled in order to have the object “ready to hand”. Furthermore, the program offer different

“Export Capabilities” that allows the render to be exported in a number of other work environments

(e.g. to Autodesk DXF).

Alas this powerful technique does not always work because not all the structures are suitable to be

well implemented. Unfortunately this is the case of the St. Torcato church.

By approaching this technique for the first time the first main problem that the group faced was in

choosing the appropriate locations from which the pictures should have been taken: the basic idea

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was to represent all the structure in a 3D render but it was immediately noticed from the in situ

investigation that this kind of structure would have been a quite demanding task. The area around the

church has space limitations thus it was very difficult to shot pictures with common reference points.

To perform a complete 3D rendering of an object it is also necessary to shot pictures from all

prospective (including from the top) and unfortunately the surrounding region of the church did not

allow to satisfactorily accomplishing this task.

To perform the image survey a 7.1 Mega Pixel digital camera has been used and cause to the

abovementioned problem the demand has been scaled down to a 2D rendering of the front façade.

Sometimes it is not so easy to take pictures from different directions. Photos are the basic information

for using Photomodeler. Building perfect models without adequate photos is very demanding.

In this case study, for examples, it was hard to take pictures from the ground up to the top of the

whole church. Due to the open space in front of the main entrance of the church the only workable

pictures that have been taken are the ones depicted here below (Figure 3-1):

Figure 3- 1: Pictures used for the 3D rendering

This two pictures has been taken from the two opposite angles of the front open space, as much

further as possible in order to include the whole façade, but the resultant angle between the pictures

resulted to be too narrow (Figure 3-2) and this led to low accuracy problems. This two pictures have

been used to “Reference and Orient” the church within the software.

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Figure 3- 2: Position of the camera while shooting the pictures

The front façade of the St. Torcato church is not a perfect 2D image. This leads to the problem that

not all the points can be seen in both images. Thus, in order to assess the same reference points

(points that allow the program to recognise and orientate the pictures) in both pictures the “edge”

option instead of the more accurate “line” option had to be used and that brought a higher level of

inaccuracy.

Furthermore, even though it was a 7.1 Mega Pixel resolution camera that shoot the pictures, due to

the problem explained before, their quality was not optimal. To perform an accurate 3D model for a so

ornate and florid structure, a much more professional camera is needed.

Due to the problem that all the pictures were shot from the ground, the final solution for the 2D

photomodeler rendering exclude the two tower’s roofs from the view as they seem distorted. This is a

result of not having enough pictures and thus reference points. The project was then focused only on

the 2D front façade and the final 2D rendering is the following Figure 3-3:

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Figure 3- 3: Photomodeler image output (1 pixel = 1 cm)

In which it can be seen a pretty good resolution of the cracks. This image fit the word document

report, but the real figure that the programme allows the professionist to save, is a 1 pixel = 1 cm

resolution picture. In this manner, with a good quality programme of “image viewer”, all the front

façade can be accurately scanned from the laptop and a more accurate crack survey can be done

directly by looking at the picture.

3.2. Defects typology

The following are the few problems found at the structure:

Structural problems (Figure 3-4):

1. Cracks, Open joints and Compression cracks

Non – Structural Problems:

1. Algae growth and Vegetation

2. Lime mortar Seepage marks

3. Birds

4. Vegetation

In the following part of the report we shall deal with these above-mentioned different types of

condition of the structure in detail.

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Figure 3- 4: General views of the Cracks

3.3. Analysis of the defects

3.3.1. Structural defects

There are cracks observed on walls and floors of the structure. The cracks vary from being a hairline

cracks to cracks as wide as 60mm. The observed cracks are of two types

The old cracks which are repaired in cement ( year 1998 )

Compression cracks ( mainly on the external walls)

3.3.2. Non structural defects

Lime mortar seepage marks: At many points along the stone joint of the external walls

one could see white seepage marks. This could be the

dissolution and leaching of the components of hydrated

mortars.

Phenomenon behind dissolution and leaching of the

components of hydrated mortars:

“This can be caused as a result of excessive hydration

and dehydration, i.e. through absorption, leakage, and

percolation or splashing of water. Pure waters (from water

vapour or condensation of fog) and soft waters (rainwater or melted snow and ice) contain little or no

calcium. When these waters come into contact with hardened mortar they spread through the porous

system of the material and dissolve the hydrated phases which are rich in calcium. CaCO3, the main

constituent of lime mortars and lime-pozzolana, has an equilibrium pH of 9.93 which is moderately far

from the neutral. Then, when CaCO3 comes into contact with water, it dissolves until reaching

equilibrium. If the waters also contain dissolved CO2 the solubility of the CaCO3 will be very superior.

The dissolution of the mortar binder can cause an increase in the porosity of the system and

consequently in its permeability. This decreases mechanical strength and leads to an increase of the

susceptibility of mortar to attack by other aggressive agents. Leaching of calcium salts from mortars

Figure 3-5: Seepage marks

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can also have other undesirable effects from the aesthetic point of view. Frequently, the leachate [Ca

(HCO3) 2] precipitates on the surface of the material or even on adjacent materials causing white

efflorescence of CaCO3”.

Vegetation Growth:

The ceiling of the 3rd level corridor shows vegetation growth (Figure 3-6). The presence of vegetation

in the open joint in the ceiling above the balcony may also be a sign of degenerated water proofing

layer in the roof.

Birds:

The openings of the towers have led to the presence of birds. The presence of the excreta of the birds

could become a cause of the deterioration of the stone members in near future.

Algae growth and Fungus:

The external walls show algae and fungus growth due to the presence of water seepage on the walls

(Figure 3-5). These are mainly found at the west façade of the West Tower and the North façade of

the east Tower.

Figure 3- 6: Vegetation growth and algae

4. NON DESTRUCTIVE TEST

NDT (non-destructive test): is a specialized technical inspection methods which provide information

about the condition of materials and components without destroying them. NDT can give hints to

irregularities within the historic masonry structure, which is often inhomogeneous.

NDT or MDT offer possibilities to:

Border problem areas

Determine hidden dimensions

Investigate variations in type and quality of materials

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Reliable statistical evidence of the material extractions and investigations

During the preparation of the report in the year 1999 there was a standard penetration test which was

done for the characterization of the soil. The details of the test are described in the next paragraph.

4.1. Standard penetration dynamic test – year 1998-99

To represent the characteristics of strength and deformability of soil, standard penetration test was

carried out in 31 locations for a depth of up to 8m around the tower and up to 4m at the transept area.

The result of the test showed that at the vicinity of the tower the presence of layers of soil from landfill

earth with extraordinarily low mechanical properties was found (Figure 4-1).

Figure 4- 1: Soil profile

4.2. Proposed NDT’s & MDT

As a follow up of the previous investigations, this year (2007 – 08) a study of the present condition of

the structure has been undertaken. After several site visits and detailed visual investigations of the

present condition of the structure, the following non-destructive testing methods are proposed.

The non-destructive plans are proposed with the aim to determine the following:

Presence of voids

Soil characteristics

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Timber quality assessment

Hence to acquire the above mentioned details it is necessary to carry out appropriate tests to get the

relevant data and values. It is also proposed to carry out two tests respectively for every proposed

aim, for more accuracy. The following tests are proposed:

1. Finding of presence of voids: Sonic wave test and Georadar test

Presence of white marks found at the joints of the external wall surface suggest that there could be

loss of the inner core, it is proposed to carry out the sonic wave test and georadar test to ascertain if

there are voids present within the three leaf stone wall.

Sonic wave test: Sonic test is a powerful method to obtain information on the conditions of a structural

element through the interpretation of velocity and attenuation. The velocity distribution is an indication

of the material’s elastic property distribution. Low velocities indicate in-homogeneity of the material.

Geo-radar test: The method is based on the radiation of very short single sinusoidal cycle

electromagnetic impulses (<1 ns) generated by a transmitting antenna, which are reflected at

interfaces of materials with different dielectric properties.

The reflections are recorded with the receiving antenna by moving both transmitter and receiver along

a profile on the surface of the tested element under test.

Facts to be considered:

If the sonic wave test & georadr test prove the rpesence of voids, it is proposed that grout injection

with appropriate material composition –which are compatible with the stone masonry’s mechanical

and visual character - needs to be carried out to fill the voids.

The other factor to be considered during injection is the quality control of the grout. The consolidation

of the wall by injection needs to be carried out with low pressure in order to ensure no damage to the

structure.

2. Timber quality: Resistograph, manual hammer, Pilodyn test

The quality of the timber truss at the 2nd level of the tower by a visual inspection looks to have no

deterioration or damage. But to ascertain the quality of the timber with values and tests it is proposed

to carry out the above-mentioned test to ascertain that the timber truss is safe and not under any

deterioration.

Manual hammer test could be carried out to approximately decide on the possible weak points on the

beams and rafters by determining the quality of sound.

Resistograph test could be carried out to find the resistance, decay, voids etc., within the timber

member. This is a minor-destructive test because of the drilling of a small portion of the timber

member; nevertheless the wood will only be insignificantly injured, and the drilling hole closes itself

due to a special drilling angle that was customized for the drill bit.

Pilodyn can also be used to detect decayed wood near the surface and the density of the piece.

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4.3. Proposed other tests

1. Evaluation of mechanical properties: few non destructive, minor destructive and destructive

tests are to be carried out, to find the Young’s modulus, strength, surface hardness, Poisson ratios

etc.. These values are required for the analysis of the structure. The destructive tests wil not affect the

structure because they will be carried out on surplus materials from the same quarry.

The destructive and minor destructive tests are proposed because generally the NDT’s doesn’t give

the required information and has its own limitations; it is also proposed to carryout the following tests

on samples procured from the same quarry where the stones of the church were quarried:

a) Ultra-sonic test

b) Compressive test

c) Surface hardness test

2. Soil Characteristics: Standard penetration test

SPT is recommended essentially for collection of disturbed sample to obtain baseline soil property

interpretation. This test would also provide us the information on soil penetration resistance.

Important criteria to be taken into account for carrying out standard penetration tests are:

The number and location of the test to be carried out

Depth of the penetration for the collection of the sample

During the SPT, it must be possible to take disturbed and undisturbed samples (using split barrel-

sampler) which would be used for further laboratory tests to be carried out by the soil specialist to find

information on the following: soil classification, structure, consistency, texture, moisture content in the

soil, organic content, water table level, chemical properties of the soil, pH value, bearing capacity,

grain-size distribution, plasticity, and compaction characteristics.

3. Recording the foundation detail ( Trial pit ):

Since the type of foundation is not known, and this plays a vital role in the understanding of the

structure, it is proposed to carry out a trial pit close to the outer plinth of the tower to ascertain the

type, depth, material etc., of the foundations.

5. MONITORING

The monitoring and instrumentation for historical building can enable to know if the damages (cracks)

are changing with applied force and environmental influences. The stability is evaluated on the basis

of geometrical measurements of the shape and position of objects, structures or structural elements

and mutual spatial relations of structural parts separated by the defect. In most cases, the movements

in the vicinity of cracks are measured.

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Influence of Temperature and Moisture:

Moreover, it is important to measure the vertical and horizontal movements of structure. Since the

movements will be influenced by the temperature fluctuations, the temperature inside and outside the

building should be measured. In some cases, the measurement can be used for checking the

temperature sensitivity of the instruments. Many building material are also sensitive to moisture

changes. The volume of some construction material, such as wood, can change significantly with

humidity difference. Normally the interior and exterior relative humidity is measured together with the

moisture content in the building material. Finally, if the structural dynamics properties are measured

for the building, some climatic parameters such as wind speed, direction and fluctuation should be

measured together with the vibration effects.

As mentioned earlier in the report, during the year 1999 there was a report prepared after the installion

of some monitoring devices by team of experts.

Following, the position of were the monitoring systems was installed is reported (in accordance with

the previous report):

a. Crack monitoring

b. Tilt recording

c. Displacement recording

5.1. Conclusions on the monitoring recordings –year 1998-99

Crack monitoring:

The Crack-meters located on 14 different locations determined that the cracks were active (Figure 5-

1).

Figure 5- 1: Crack meters

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Tilt monitoring

Using a Clinometers installed one in each tower the angle of the tower was measured. From this test it

was noticed that slope of the towers of the order of 2 × 10-5 rad (Figure 5-2).

Figure 5- 2: Tilt meters

Displacement monitoring

Using an optical Theodolite – total station the displacement of the towers, floor and arches of the nave

had been recorded. The results of the recording were as follows:

• the bell towers are tilting with transverse displacements;

• the inclinations are of the order of 8 × 10-4 rad for the left tower and 12 × 10-4 rad for the right

tower

• the arches in the main nave and the ground floor showed vertical deformations.

5.2. Monitoring proposal and location

After the analysis of the damage survey mapping recorded of the Church over this session, the

following proposal for the monitoring systems to be installed for recording and monitoring the condition

of the church is given.

The following features were considered while the locations of the sensors and Crack-meters were

finalized:

the sensors, Crack-meters and tilt-meters recordings are interdependent on each other for

understanding and analyzing the recordings;

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the recordings of the sensors are dependent on the locations, because the values of the

recordings change significantly with the sunlight falling directly over the sensors;

location of the crack meter depend very much on the understanding of the crack pattern and

the structural movement;

Cost plays a vital role, because each of the above mentions equipments are highly expensive,

and the numbers significantly affects the cost of the project.

Crack meters: The Crack-meters (Figure 5-3) are used for cracks

measurement. The Crack-meters are to be mounted across joints or cracks

by installing a pair of anchor stems. Pre-positioned holes are to be drilled on

each side of the crack or joint. The Crack-meters are to be assembled onto

the pair of anchors and extended to allow for the expected direction and

magnitude of movement. The expected resolution is up to 0.025% FS. The

specification can be referred to Soil Instrument.

Locations of the crack meters: for deciding on the number of sensors & meters and their location the

following understandings of the structure are highlighted:

1. the deep severe cracks on the walls of the nave denote that the towers are getting detached

from the main nave and settling towards the south direction;

2. the cracks on the ceiling of the first level and the cracks seen of the walls of both first and the

second level support the fact that tower is also settling and splitting in east-west direction;

3. because of the settlement occurring towards the south end of the church, the towers are

tilting.

Hence, with reference to the above mentioned points, the following locations to fix the crack meters

were decided

One crack meter on the east wall of the nave at the level 2

One crack meter on the west wall of the nave at level 2

Two crack meter along the two cracks on the south internal wall at level 2

One crack meter at the parapet crack on the south external wall at level 2

One crack meter on the south internal wall at level1

Tilt meters: Tilt meters are used for measurement of vertical movement of the church. They can be

cable free and be directly fixed to the church. An analog/digital converter and digital radio is integrated

into the tilt meters. The resolution of the equipment is ± 5mm/meter sensor. The range is ± 2.5

degrees. The specification can be referred to Soil Instrument.

Locations of the Tilt meters: Since the tilts are found on the tower it is proposed to place one tilt

meter at each tower.

Temperature sensor: The accuracy expected is about ± 0.04% FS. The temperature sensors are to

be located in a way that the internal building temperature and the external ambient temperature can

be recorded. There is a need to place one temperature sensor along with the tilt meters too.

Moisture sensor: Operation of the sensor depends upon the adsorption of water vapour into a porous

Figure 5.3: Crack

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non-conductors "sandwich" between two conductive layers built on top of a base ceramic substrate.

The moisture sensors are to be located in the manner that the internal building humidity level and the

external environment humidity levels are simultaneously recorded.

Locations of temperature and moisture sensors: The locations of these sensors are directly related with the location of the tilt meters and presence of

the sunlight. Following are the decided locations:

One temperature sensor each along with the two tilt meters

One temperature and humidity sensor outside at the balcony of the second level to capture

the external ambient temperature and humidity

One temperature and humidity sensor inside the building at the level 1, to capture the internal

temperature and humidity.

Data-logger and Receiver: The radio logger needs to operate as the hub of a static collection system

(Figure 5-4). It has to be collecting readings from radio sensors directly, or via repeaters, storing them

in non-volatile memory.

The system has to allow utmost flexibility in methods of powering the unit, as well as a variety of

choices on retrieving data. The handheld receivers have no storage capacity, but by direct connection

to a laptop it should allow data to be recorded.

Figure 5-4: Datalogger

The data logger needs to be combined with Net-Site web based software to allow password protected

Internet access to near real time data from large or small projects.

Data-logger reads up to 100 sensors

Output via RS232 or GSM (SIM required)

20 channel handheld receiver (RS232 output)

Comes with CF Loggit communication software for loggers

Comes with CF Receiveit communication software for receivers

Location of the data logger: The criteria on which the location of the data logger was decided are as follows:

Location of an existing power socket

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Closer proximity to maximum number of monitoring systems proposed

Hence it is proposed to locate the data logger box at the west wall of the nave on level 2 (Figure 5-5

and Figure 5-6).

CM 01

CM 03

CM 04 CM 05

CM 02

CM 06

TM 01 TM 02data logger

LEVEL - 3 PLAN

LEVEL - 2 PLAN

PROPOSED LOCATION FOR THE MONITORING SYSTEM - S. TORCATRO CHURCH, PORTUGAL

CM 00 - CRACK METER 6nosTM 00 - TILT METER 2 Nos

T 00- TEMPERATURE SENSOR 2 noTH 00 - TEMPERATURE & HUMIDITY SENSOR 2 no

DG 00 - DATA LOGGER 1 No

DT

W 00 - ANENOMETER 1 no

T 1 W1

TH 1

TH 2

N

A

ADrawing to be read in realation to the Section drawing

T 2

Figure 5-5: Monitoring system - Plan view

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CM 02

CM 04

CM 03

CM 05

W1

data logger DT

PROPOSED LOCATION FOR THE MONITORING SYSTEM - S. TORCATRO CHURCH, PORTUGAL

SECTION - AA True Scale Drawing to be read in realation to the Plan drawing

LEVEL - 1

LEVEL - 2

LEVEL - 3

CM 00 - CRACK METER 6nosTM 00 - TILT METER 2 Nos

T 00- TEMPERATURE SENSOR 2 noTH 00 - TEMPERATURE & HUMIDITY SENSOR 2 no

DG 00 - DATA LOGGER 1 No W 00 - ANENOMETER 1 no

Figure 5-6: Monitoring system – cross section

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6. DYNAMIC IDENTIFICATION

A dynamic investigation on the two towers and the main façade of the St. Torcato church has been

carried out with the supervision of Prof. Luis Ramos and PhD Rafael Aguilar with the aim to perform a

preliminary analysis to study the dynamics parameters (natural frequencies, mode shapes and

damping coefficients) in order to assist on further and complete modal identification analysis of the

structure.

As the towers have their first mode shapes in the x-y plan (plan view), it was decided to measure

accelerations only in this plan. In the case of the façade, only out-of-plane vibrations (y direction) were

measured.

For the present analysis, output-only tests (or ambient vibration tests) were used to estimate the

modal parameters. These experimental techniques only take the measurements of the response to

estimate the modal parameters. Therefore, the excitations are unknown or unmeasured. Ambient

excitations and the bells ringing were used to excite the structure.

Four piezoelectric accelerometers were used to measure the vibrations. Basically, the accelerometer

is one spring mass damper system which produces signals proportional to the acceleration in a

frequency band below their resonant frequency.

The ADC used for this study reads at a minimum of 2000 points per second (sampling frequency of

2000 Hz). As the computer can only read digital signals, it demands the converting of the analog

signal into digital signal, the so called digitalize process. In this process, the resolution depends on the

available number of bits used to digitalize the signal.

6.1. Test planning and results

Before going to the field, a preliminary test plan was prepared. In the case of the towers, the sensors

were installed in its upper part, the part with higher amplitude of movements. As the ADC available is

only capable to read four accelerometers at the same time and it was planned to measure

accelerations in the four corners and in two directions, three setups measurements were carried out.

More information about the scheme of the setups for both towers and the front façade are presented

with Figures and pictures in Annex B. The sensors disposal allows distinguishing the bending modes

shapes from the torsion mode shapes. In the case of the front façade, the sensors were installed over

the balcony floor. All sensors were located along the transversal edge in the direction y. Due to lack of

time, just one setup measurement was carried out. A scheme of the works and a brief explanation of

the methodologies used are presented in Figure 6-1 and 6-2.

St. Torcato Church



22

Figure 6- 1: test in the Tower: (a) measuring points and (b) setups description.

The sensors disposal allows distinguishing the bending modes shapes from the torsion mode shapes.

Figure 6- 2: Scheme of works in the front façade: plan view

The conclusions of these preliminary results are the following: for the Left tower it has been possible

to observe a first group of stable poles around 2 Hz and a second group of less stable poles from 9 Hz

to 20 Hz (Figure 6-3). On average and for all the setups, it has been possible to identify four close

frequencies at 2.13, 2.61, 2.83 and 2.92 Hz. The average damping factors for the three setups are

1.03%, 1.03%, 0.73% and 0.9%. The first frequency corresponds to a mode moving in the x direction,

while the second, the third and the fourth modes correspond to movements in both x and y directions

(Figure 6-4).

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23

Figure 6- 3: Stabilization diagram of setup 1 (left tower)

Figure 6- 4: First Mode shapes of the left tower.

For the right tower it has been possible to identify two groups of poles: a first one with stable poles

around 2 Hz and a second one with less stable poles between 9 and 20 Hz (Figure 6-5). On average

and for all the setups, it is possible to identify three closer frequencies at 2.14, 2.62 and 2.85 Hz. The

average damping factors for the three setups are 1.0%, 0.9% and 1.0%. The first frequency

corresponds to a mode moving in the x direction, the second correspond to movements in the y

direction and the third one corresponds to movements in both directions (Figure 6-6).

St. Torcato Church



24

Figure 6- 5: Stabilization diagram of Setup 1 (right tower)

Figure 6- 6: First mode shapes of the right tower.

For the Front façade it has been possible to observe that there are two groups of poles, the first one

around 4 Hz and the second one over 10 Hz (6-7). It has been possible to identify four closer

frequencies at 2.58, 2.93, 4.06 and 4.34 Hz. The damping factors are 2.2%, 2.5%, 6.4% and 7.3%.

The mode shapes are depicted in Figure 6-8.

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25

Figure 6- 7: Stabilization diagram of front façade

Figure 6- 8: First mode shape of front façade

More details about the dynamic identification can be assumed from a previous report1.

A F.E.M. model (the same used for the strengthening purpose – see chapter 6) has then been used to

check these preliminary results. The obtained results for the first 5 modes are shown in Table 1.

MODE FREQUENCY GEN. MASS PARTICIPATION1 0.7200 0.9749 81.17902 0.8648 0.9577 57.05103 2.5152 0.9374 147.83004 2.8555 0.9765 33.82905 4.6150 1.1329 -1.2692

Table 1: Frequencies of the first mode shapes

The first two modes are strongly affected by the stiffness properties of the soils, while the following

modes have the same magnitude of the in situ test. The deformed shape of these modes shapes is

shown in Figure 6-9.

1 L. Ramos, R. Aguilar, “Dynamic identification of St. Torcato’s Church:Preliminary tests”, Guimaraes, 2007

St. Torcato Church



26

Figure 6- 9: Mode shape 3, 4 and 5

These shapes cannot be compared with the ones obtained from the dynamic identification. The afore

measurements, calibrated with the two towers, the front façade and the F.E.M. model gave no similar

results in terms of mode shapes. Further calibration of the model should be carried out. The

encountered differences might be due from the not complete F.E.M. Model (the transept part is

missing) and the local dynamic identification carried out. As a matter of fact the following step of the

dynamic identification should be to estimate the frequencies of the whole church by a global and

spread position of the accelerograms.

7. STRENGTHENING TECHNIQUES

The strengthening proposal for the St. Torcato church consists in different phases and should aim at

the following steps.

Leading all the intervention, the installation of an accurate monitoring system has to be achieved. This

system must satisfy all the needs for further analysis on the structure (e.g. for calibration purposes)

and must remain active during and after the strengthening intervention. The strengthening must then

started from the consolidation of the foundations: this is the main problem that affects the structure

due to the irregular stratigraphy and the loose constitution of the soil. This step must then be followed

by a period of monitoring only to check if the structure has been correctly stabilized. A correct design

for the consolidation of the foundation of the St.Torcato church should prevent any further settle of the

structure thus to avoid any further damage.

The following steps proposed in this report are practices that have to be taken into account only if the

strengthening of the foundation does not fulfil the expected results. These unexpected behaviours

should easily come out from the monitoring system outputs.

After all the works have been done, the monitoring system should be kept active for the following

St. Torcato Church



27

years.

7.1. First phase: Foundation strengthening

As mentioned in the earlier part of the previous study of St. Torcato Church (Ramos, 1999), differential

settlement was detected on the both towers and façade (Figure 7-1). The differential settlement was

the main cause of the cracks on the façade and other parts of the church.

The reasons for settlement are probably due to the uneven consolidation of soil layers. In this section,

foundation strengthening method for solving this different settlement will be proposed wherein the

existing foundation will be strengthened by micropile.

Figure 7- 1: settlement contour of the church (Ramos, 1999)

7.1.1. Subsurface conditions

It was mentioned that the soil strata consists of five to six layers. Starting from the superficial layer of

the soil strata, the soil type is described as (a) transported soil with organics (b) decomposed granite

(c) organic soil (d) cohesion less decomposed granite (e) decomposed granite with boulder (f) bed

rock. (Ramos, 1999) The thickness of each layer is shown in Figure 7-2. It can be seen that the

thickness of first four layers is not much different. Special attention should be paid to the layer of

decomposed granite with boulder. This layer is characterized as thick and non-uniform one. The

thickness varies from 4 m to 8 m (under the tower). It may create the uneven consolidation problem.

St. Torcato Church



28

Figure 7- 2: Soil Strata for St Torcato Church (Ramos, 1999)

7.1.2. Foundation strengthening technique

Different types of foundation strengthening techniques have been examined for the suitability of

foundation repairing. Three major types of strengthening are sorted out: namely, underpinning

(enlargement), grouting and micropiling. Effectiveness, minimum intervention and environmental

cleanness will be the important factors for the choice. A comparison of suitability is listed.

Effectiveness Minimum Intervention Environmental

Cleanness

Underpinning ●● ● ●●

Grouting ●●● ●● ●

Micropiling ●●● ●●● ●●●

The highest score is micropiling. It is considered to be the best method since it fulfils all three criteria.

The method is simple and quick. The effectiveness can be easily checked by proof load test of the

piles. The disturbance during construction is minimized.

It can be concluded that micropile is the best method to be used in this project.

7.1.3. Micropile background

Historically, micropiles appeared in Italy in early 1950s for repairing historical building and monuments

that had sustained damage, especially after World War II. The system is reliable because it provides

the support for structural loads with minimum movement and disturbance to the existing structure. The

St. Torcato Church



29

strengthening can be performed in many ways:

To prevent the structural movement

To upgrade load-bearing capacity of existing structures

To repair deteriorating or inadequate foundations

To add scour protection in bridge foundation

To raise the deformed structure to the original position

To transfer loads to deeper strata

7.1.4. Design methodology

A proper design for foundation system should include:

Determination of foundation load in kN/m

Selection and determination of capacity of individual pile

Determination of pile spacing

Layout of the pile group

It should be emphasized that a successful and economical design is based on detailed understanding

of the soil under the structure, for example, the strength and compressibility of each soil type.

Unfortunately, due to lack of these types of soil exploration in this study, a preliminary and

conservative approach is adopted. The following assumptions are made:

The pile foundation is end bearing pile which is socketed into the bedrock directly

The bedrock is unweathered granite with unconfined compressive strength of 100 MPa

The deformation of pile in the rock is negligible

7.1.5. Introduction to piling machinery

A hydraulically driven steel push pier system manufactured by Magnum Piering, Inc. may be used to

repair the existing foundation (Figure 7-3). This system consists of steel brackets attached to the

existing footings. A hydraulic ram capable of exerting up to the required force on the steel pier is

attached to the bracket. Dead load from the existing structure is used as a reaction to drive the piers,

which can be high strength steel pile and helical steel member.

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30

Figure 7- 3: Hydraulically driven steel push pier system

(courtesy of Magnum Piering, Inc.)

7.1.6. Design and installation Data

Determination of pile capacity:

The ultimate capacity of a pile is limited by the structural capacity of the pile and the capacity of the

surrounding soil/rock to support the loads transferred from the pile. In this case, the capacity of pile is

controlled by the soil/rock capacity and it is computed on the basis of bearing capacity of rock.

The capacity of pile is determined as follows:

The bearing capacity of bed rock, qt, which is unweathered granite in Portugal commonly, is assumed

to be 100 MPa. For the solid steel pile of 15 cm diameter, the cross section A is 177 cm2.

The bearing capacity for pile Q = qtA = 1767 kN

The foundation load and pile spacing for the different parts of the church is calculated as follows:

For Nave:

Dead load = 23 m (height) × 1.2 m (outer wall) × 25 kN/m3 = 690 kN/m

For a pile capacity of 1767 kN, the spacing is 1767/690 = 2.55 m (2.6m)

Steel pile: 15 cm diameter length @ centre to centre spacing of 2.6 m

Total pile for Nave = (18.78/2.55) × 2 = 16

For the tower:

Dead load of one tower = 33000/20 = 1650kN/m

For a pile capacity of kN, the spacing is 1767/1650 = 1.07 m (1m)

Total pile for towers = 19/1 × 2 = 38

Two additional pile is installed at the corner of each tower. Total pile number = 38+2 = 40

For the façade:

Dead load = 23 m (height) ×1.2m (outer wall) × 25 kN/m3 = 690 kN/m

For a pile capacity of 288 kN, the spacing is 1767/690 = 2.55 m (2.6 m)

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31

Total pile for façade = 14.54/2.55 = 6

The layout of pile location is given in Drawing FS01.

Because the pile is designed with rock socket length of 1m, the pile length varies along with layer of

bed rock layer from the nave to the façade direction, namely from 8 m to 11 m. The pattern of each

pile is given in Drawing FS02.

It is clear that an extensive number of pile (totally 40) is required for strengthening the towers, which

are the heaviest part of the church. Actually, the pile and soil forms an integrated stabilization mass.

For the optimizationg pile purpose, the pile in the lateral part of tower will be installed with an

inclination angle of 20 degree to the vertical (see Drawing FS02). This part of inclined pile will provide

lateral capacity to resisting any load due to structural movement.

It should be noted that this foundation strengthening design is conservative. For a more realistic and

economic one, understanding of mechanical behaviour of each type of soil is necessary. A complete

soil exploration test is then required.

7.1.7. Connection design

The success of design depends on the good connection of the wall and foundation system. According

to the manufacturer of Magnum Piering, Inc. (Figure 7-4), three type of connections are recommended

for use, namely, single bolted connections, double bolted connections and triple bolted connections.

The triple bolted connection is used for heavy duty load. An 18mm bolt full pattern connection is used,

corresponding to the design wall loading (Figure 7-5). For this setup, the Magnum Piering bracket is

secured using 12 mm diameter - 140 mm long expansion bolts extending into the side of the footing.

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32

Figure 7- 4: Pile Wall Connection Detail

(From: Magnum Steel Push Pier Technical Reference Guide)

Figure 7- 5: Bolt Setup from Magnum Piering Bracket

St. Torcato Church



33

7.1.8. Installation specification

A summary of the micropile specification is given as follows:

1. General: Necessary measures must be provided for protection of church

2. Setting Out: Locating the position of piles

3. Scope of Works

Site Formation

Supply and installation of piles

Cutting the piles to cut-off preparation of pile wall connection

Carrying out standard pile load test

4. Material

Steel pile

Metal Connection

Grout

5. Site and Adjacent Properties

Subsoil data

Underground Services and Adjacent Properties

6. Drilling Operation

Rock Coring

Rock socket length

Rock head existing in the soil layer

Inspection of Pile excavation

7. Standard Load Tests

Understanding of the load capacity after installation

At least 1.5 working load must be applied for testing

The detailed information of the installation specification is given in the Annex B.

7.2. Second phase: Tie rods strengthening

Taking into account the analysis and the justifications of the pathologies encountered so far and the

detected main problems of the church (splitting onwards of the façade and tilting outwards of the

towers), we decided to carry out a structural analysis to propose another intervention.

As mentioned at the beginning of this chapter, the tie rods strengthening proposed hereafter has been

studied as a solution to be applied only if the strengthening of the foundations does not give its

desired results (to be checked with the monitoring system).

In order to begin the analysis the full load analysis have been carried out by deducing it from the

previous report. The loads acting on the structure are the followings:

The self weight;

St. Torcato Church



34

The weight of the pyramid roof equal to 587 kN, that correspond to a distributed load on each

wall of 28.25 KN/m (and a horizontal thrust of 2.84 kN/m);

The weight of the reinforced concrete that serves as pavement for the landing at the

bells level equal to 259.2 kN, again simulated through a vertical distributed load

of 9.0 kN/m, on each wall;

The weight of the coverage of the nave, with timber structure roof, and tiles cover, simulated

through a vertical uniform load of value of 6.5 kN/m, distributed in the central width area of the

facade;

Due to the lack of information about the total weight of the bells, an additional vertical load has

been admitted of 2.0 kN/m2, simulated by a vertical action uniformly distributed in each wall of

3.6 kN/m.

In Figure 7-6 is represented the subdivision of the main façade of the church with regarding to its

height.

8.7 m

8 m s = 1 m

10 m s = 1.4 m

18.6 m s = 1.4 m

4.4 m s = 1.54 m

H tot = 49.7 m

Thickness of thetower walls for eachlevel:

Height in which the tower hasbeen subdivided:

Figure 7- 6: Front elevation

The first hand calculations carried out to evaluate the safety of the structure taken into account some

preliminary hypothesis.

By knowing the east-west tilting movement of the towers, the first assumption to calculate a first

dangerous kinematism for the church was to believe no connection between the lateral walls (red in

Figure 7-7) and the orthogonal walls of the towers.

St. Torcato Church



35

Figure 7- 7: Schematization of the front façade for the first collapse mechanism

As cracks already occurred in the structure, there is no point to look for the satisfaction for the safety

verification with regards to the DLS, but it is better to focus on the ultimate limit state verification of the

local mechanism (which is MANDATORY), in order to assure the safety with respect of the collapse.

This verification can be developed through the criteria of simplified verification with structure factor q

(so called linear kinematics analysis).

7.2.1. Simplified verification

The verification is satisfied if:

⎟⎠⎞

⎜⎝⎛ +≥

HZ1.51

qSa

a g0

* This is the demand parameter to be compared with the capacity parameter

where: q is the structure factor assumed equivalent to 2, Z is the height of the centre of the masses

that generate horizontal forces on the elements of the kinematic chain and H is the height of the whole

structure.

The parameter related to the zone of the municipality of the ST.Torcato has been extrapolated from

the latest draft of the portuguese national zonization.

By following this path, the main results and the elevation of one of the red walls depicted in Figure 7-7

are showed here below:

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36

N1 = 20 kNN2 = 64.8 kNN3 = 146.75 kN

W1 = 169.4 kNW2 = 1001 kNW3 = 200 kN

A wall band 1 meter wide is considered, in the original configuration. The hypothesized kinematism is

given by a rotation of the whole wall around the hinge A. This simplified approach should then be

followed by the rotation around the hinge individuated by the point where the reacting section ends,

whose amplitude (distance ti) can be determined by limiting the maximum stress in the most

compressed edge to the value σc = 2 MPa (for the granite compressive properties)

Considering the following loads:

The kinematism is a simple rotation; therefore the VWP is reduced to a simple rotation

equilibrium of the horizontal and vertical forces around to the hinge A. The equilibrium is

satisfied if:

(1)

And the factor for which this relation is satisfied is the following:

RS MM =

032.00 =α

S.Torcato

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37

∑∑

=

=

⋅

⎟⎟⎠

⎞⎜⎜⎝

⎛

=

1,

2

2

1,

*

iixi

iixi

Pg

P

Mδ

δ

=⎟⎠

⎞⎜⎝

⎛ +≥HZ

qSa

a g 5.110*

∑=

=

1

*

iiP

gMe

===∑

=*

0*1

0

0*

eg

M

Pa i

iα

α

The spectral acceleration is :

M* = 130.4 kN

e* = 0.799 m/s2

a0*/g = 0.040 g

Where: is the participant mass

is the fraction of the mass participant to the kinematism

0.040 g is the capacity curve parameter

0.096 g is the demand curve parameter

The verification is then not satisfied because the capacity parameter is below the demand parameter:

With the same simple assumptions a more defined analysis has been carried out by refining the

macro elements in which the wall has been divided and introducing a tie force T

(red in the following picture) that aid to structure not to collapse. Here are the basic

calculations:

A wall band 1 meter wide is considered, in the original configuration. The

hypothesized kinematism is given by a rotation of the whole wall around the hinge

A. This hinge is individuated by the point where the reacting section ends, whose

amplitude (distance ti) can be determined by limiting the maximum

stress in the most compressed edge to the value σc = 2 MPa.

gg 096.0040.0 ≤

N1 = 20.00 kNN2 = 20.00 kNN3 = 18.51 kNN4 = 20.96 kN

W1 = 169.40 kNW2 = 651.00 kNW3 = 350.00 kNW4 = 200.00 kN

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38

α0 = 0.095M* = 112.3 kNe* = 0.760 m/s2

Capacity a0* = 0.125 gDemand a0* = 0.093 g

Verified

By inserting the tie rod and evaluating the force that allows satisfying the equation (1) with a α value

corresponding to the PGA of the municipality zone (0.08g), the force of each of the two tie rods has

been evaluated of : Fties = 97.33 kN which corresponds to a diameter of about 23 mm.

But due to the very restrictive assumptions (no connection between the orthogonal walls) this

procedure cannot be enough to evaluate the Force at which the tie rods should be subjected.

Hereafter a new approach is explained, in which the connection between the walls is taken into

account by simulating a triangular mass that all detached from the main body (Figure 7-8).

Considering this behaviour (more likely to occur with respect to the other) the final

verification says that there is no need to insert any strengthening between the

towers. A reason for this solution may be found by considering the massive weight

of the structure. Moreover, the associated triangular shape in the figure, which

represent a portion of the orthogonal walls (which work in their plane) bring more

stabilizing mass to the behaviour and thus more safety.

With the same procedure, the following result can be obtained:

Figure 7- 8

α0 = 0.051M* = 51.80 kNe* = 0.862 m/s2

a0* = 0.580 ga0* = 0.117 g

CapacityDemand

Verified

Overturning Point B:

α0 = 0.038M* = 100.44 kNe* = 0.782 m/s2

a0* = 0.474 ga0* = 0.103 g

CapacityDemand

Overturning Point A:

Verified

α0 = 0.101M* = 21.02 kNe* = 0.933 m/s2

a0* = 0.118 ga0* = 0.098 g

CapacityDemand

Overturning Point C:

Verified

α0 = 0.011M* = 112.3 kNe* = 0.760 m/s2


Overturning Point O:

Not Verified

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39

Another possible mechanism that can arise, but less important with respect to the high stiffness of the

body “tower” is showed in the Annex B.

7.2.2. Limit analysis

A more refined approach to assess the level of safety of the structure has been carried out by

conducting a limit analysis.

Considering the seismic vulnerability of churches, the use of local models appears not only the easiest

way to follow but also the most correct. Contrary to the modern buildings, which behaviour as single

unit being created with vertical elements (pillars) and horizontal (beams) perfectly connected, the

historical buildings are usually the result of continuous transformations and each phase is carried out

with different materials or techniques and is not completely scarfed with the existing.

Thus the designer must divide the church in macroblocks defined as "part constructively

recognizable and accomplished of manufactured goods, which may coincide with an identifiable part

(also in the architectural and functional aspect, e.g. façade, apse, chapels); it is usually formed by

several walls and horizontal elements connected to each other to form a block which is considered as

an unitary constructively part, although generally independent and not linked by complex

Construction". The main macroblocks individuated for the St. torcato church are showed in the

following elaborations and they are mainly be evaluated by considering the actual crack pattern of the

church and its predictable movement.

The seismic collapse of a building wall will typically occur due to loss of balance of portions of the

structure, rather than overcoming a tensional limit state resistance. For each macroelement all

possible collapse mechanisms must be identified, each obtained by transforming the structure,

introducing plans fracture, in a kinematics of rigid blocks rotating or flowing to each other. Evaluate the

masses and related centres of gravity of each block, as well as any other internal or external forces to

the system, for the seismic verification is to calculate the multiplier horizontal limit collapse;

This can be done by giving the system the state of infinitesimal movement associated with kinematics

and applying the virtual work principal.

The typical collapse mechanisms are determined, on the base of the observation of the collapse

modalities of the existing buildings, collected in abacuses divided depending on different construction

typologies and the determined mechanisms are schematized with kinematic models, based on

equilibrium conditions, which provide a collapse coefficient for the elementary mechanism, i.e. the

seismic mass multiplier that leads the element to failure.

A range of index had been elaborated (Lagomarsino et al., 1997) for assessment of damage produced

by the earthquakes (e.g. Umbria and the Marches), based on sixteen indicators, each representative

of a possible kinematic mechanism of collapse for the different macroelements The combined

assessment of the level of damage and of the construction characteristics allows quantification,

through an index, of the damage produced by the earthquake and definition of a vulnerability index of

the church.

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40

In the case of the St.Torcato church three main dangerous global kinematism and one local

kinematism has been identified, all related to the crack pattern survey explained in the previous

chapter (other secondary mechanisms, such us the partially overturning of the towers, have been

discarded cause of their not likely chance to occur – see Figure 7-9). These kinematism are explained

in the following paragraphs. In all the subsequent iteration it has been assumed that the sinking of the

church due to the loose soil is avoided.

Figure 7- 9: Rejected mechanisms

7.2.2.1. First mechanism

Figure 7- 10: First macro block mechanism

The first kinematism which has been identified is the one concerning the main crack in the front

façade (Figure 7-10). The tilting of left tower may lead to an overturning of the selected macro block.

The calculation shows the overall safety of the mechanism, most likely due to the massive proportion

of the macroelement that, with its own self weight, is able to counteract the horizontal inertia forces.

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41

Acting with the same procedure explained in the previous paragraph the results are the following:

α0 = 0.186M* = 4343.7 kNe* = 0.947 m/s2


Verified

With an overall safety factor of

7.2.2.2. Second mechanism

Figure 7- 11: Second macro block mechanism

The second kinematism which has been identified is the one concerning the specular crack in the

front façade, the one spreading eastwards from the rose window (Figure 7-11). The tilting of right

tower may lead to an overturning of this particular macro block. Here again the calculation shows the

overall safety of the mechanism, most likely due to the massive proportion of the macroelement.

Acting with the same procedure explained in the previous paragraph the results are the following:

3.13

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42

α0 = 0.184M* = 4254.5 kNe* = 0.953 m/s2


Verified


7.2.2.3. Third mechanism

Figure 7- 12: Third macro block mechanism

The third kinematism which has been identified is the one concerning the possible detachment and

consequently inwards overturning of the whole front façade due to the cracks that arise in

correspondence of the first window of the both lateral walls (Figure 7-12). Here again the calculation

shows the overall safety of the mechanism, even with a lower safety factor compared with the other

two more likely mechanism. Acting with the same procedure explained in the previous paragraph the

results are the following:

α0 = 0.164M* = 8830.1 kNe* = 0.968 m/s2


Verified

2.24

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43


7.2.2.4. Fourth mechanism - local

Figure 7- 13: Fourth macro block mechanism (local)

The fourth kinematism concerns the possible local overturning of the tympanum (Figure 7-13 c shows

this mechanism contemplated as a higher mode in the F.E.M. model). This architectonic element

seems to be well connected to the massive wall just behind it, thus the mass of this component helps

in defining the overall safety of the tympanum relating to its local overturning:

α0 = 0.205M* = 339.1 kNe* = 0.982 m/s2


Verified


7.2.3. Strengthening design

To have an estimation of the total force at which each tie rod will be subjected the following main

assumption has been taken into account: the strengthening of the foundation is not fully effective and

the church keeps sinking in a most likely slowly manner.

By knowing the tilting of the left tower (the most tilted of the two) depicted in the previous report on the

St. Torcato church, the angle on which this tower is rotated has been evaluated and the resultant

horizontal force calculated by geometrical meanings. The measure of the tilting of the towers had

been evaluated through a pendulum installed at the intrados of the top slab of each tower. Thus the

measures reported here after are representing the tilting configuration as measured in 1999. This

1.94

1.69

St. Torcato Church



44

devices had been removed during the same year and to have a better estimation and knowledge

about the behaviour of the towers the group proposed to bring back a tilt meter device in order to have

new measures after 10 years (Figure 7-14).

Tilting of the left tower

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

-0.05 -0.03 -0.01 0.01 0.03

Displacement [m]

Hei

ght [

m]

displ [m] H [m]0.0000 2.09900.0018 4.04900.0060 4.56200.0081 4.78800.0086 6.88500.0099 9.12200.0067 11.24800.0032 13.08000.0028 14.8940-0.0031 16.8130-0.0009 17.2660-0.0331 26.9490-0.0295 28.7780-0.0336 34.2620-0.0382 35.7060-0.0407 37.1590

Figure 7- 14: Description of the tilting of the left tower

The red trend line illustrated in the picture allowed the evaluation of a tilting angle of about 0.095° and

the rough evaluated force came out to be about 75 kN. The strengthening procedures (the design

drawings are reported in the Annex B) consist in two pairs of tie roads, one for each longitudinal

direction. Thus each tie rod takes half part of the calculated force.

In the following pages the design of the tie rods and the steel carpentry will be discussed.

As already mentioned, the strengthening procedure consists in applying four tie rods: two of them in

direction east-west to constrain the two towers, and two in direction north-south to constrain the main

façade from the overall tilting. In the following, only the design of the most stressed tie rod will be

showed.

For the granite with which the church has been built a tensile strength of ft = 100 kN/m2 can be

assumed, according to the simplified table in the Eurocode 6.

For the design of the tie plate (design drawings in Annex E) we assume a circular stainless one:

Parameters: Lateral surface of the cone : 2.27 m2

Circular radius : r1 = 0.125 m

( ) =+⋅⋅= RrlSl 1π

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45

Bigger Radius of the cone: R = 0.725 m

Diagonal length of the cone: 0.85 m

Thickness of the wall: s = 1.4 m

An example for the circular stainless steel plate can be seen in the following Figure 7-15.

Figure 7- 15: detail of the tie plate

After the proposed georadar inspection, possible injections may be needed to locally strengthen the

part of the wall where the tie plate will be placed.

The following formulas show the maximum tensile stresses tolerated by the masonry wall by the

subsequent mechanism:

cohesion of the masonry: 80.11 kN

Tearing: 160.22 kN

Punching/ friction : 91.8 kN

where :

- friction f = 0.4

- weight above the tie W = 450 kN/m2 due to the weight of the wall above the position of

the tie: H = 18 m with a density γ = 25 kN/m3.

The maximum tensile stress tolerated by the masonry wall is the minimum between the above

mentioned mechanisms: 80.11 kN

The maximum force calculated for each ties is : F = 37.5 kN < 80.11 kN

Thus the verification for the granite stone masonry wall is satisfied.

Hereafter, an alternative solution for the tensile stress in the masonry wall can be described by the

formula:

where:

- σ is the stress due to the part of the wall above the tie

- tan ø can be considered equal to 0.4 (in favour of safety)

where A is the area of a single stone where it is hypothised to place the steel plate.

( ) =+−= 221 srRl

=⋅⋅⎟⎠⎞

⎜⎝⎛ += tfssrT

211 π

( )( ) =⋅⋅++= tfsrRrT2

22 112 ππ

( ) =+= 13 2rsfWsT

( ) == 321max ;;min TTTT

tiesr τφστ ≥⋅+= tan2.0

AFties

ties =τ

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46

From the previous equation the following result can be obtained:

τr = 380 kN/m2 > 75 kN/m2 = τties Verified

Hereafter the design of the stainless steel tie will be described:

The steel used for the strengthening purpose is a stainless steel (AISI 316L). This choice is mainly

due to the fact that most of tie rod will be subjected to the environmental condition and the must avoid

corrosion that leads to expansion and thus damages.

Considering a yield strength for the stainless steel of 220 MPa the dimension of the tie rod can be

evaluated:

1.705 cm2

We can then calculate the minimum diameter for each stainless steel tie rod: dmin =1.47 cm

But considering the long term load effects that can be originated in tie rods subjected to pretty high

stress level (they can begin to constantly deform if subjected for a long period to a tensile stress of

60% of their yield stress) it is better to increase this dimension up to 3.5 cm. Doing so a reasonable

safety factor is taken into account and it can be evaluate by the ratio of the effective tensile stress in

the ties and its design yielding value:

ft = 38.98 MPa < 220.00 MPa

with a corresponding safety factor of 5.64

Considering now the heating and cooling of the ties:

The objective of the strengthening is not to bring back the tower together in their original position, but

to avoid their progressive tilting. Following this idea the strengthening measure will be a passive one

and the initial stress that will be applied to the ties will be very low, as a magnitude of 5 Mpa.

Bearing in mind that the tie must guarantee a traction force of 37.5 kN, during their installation phase

they will be heated, and their successive thermo elongation will guarantee a more easy installation

between the tie plates.

As the length for the ties in both direction will be of approximate 30 m, due to structural reasons of

ease of formal construction to be correctly implemented, the rods will be formed by several pieces,

appropriately linked with turnbuckle. This unions may be also implemented to able to tighten the rods,

if necessary. An example is depicted in Figure 7-16.

==y

ties

fF

A

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47

Figure 7- 16: Example of turnbuckle

The position of the tie rods will be so that they will be hidden from the outside view (Figure 7-17); the

transversal tie rods (between the 2 towers) will pass for their full length inside the church and above

the vault (in which the assess is restricted to the maintenance personnel only) while the longitudinal

rods will be partially external but they will lie above a cornice that will hide them (Figure 7-18).

Figure 7- 17: Hidden position of the tie rods (dashed red), above the lateral cornice

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48

Figure 7- 18: Position of the tie strengthening in a 3D prospective

Furthermore the solution with stainless steel plates (partially hidden in this case) perfectly integrates

with past interventions in most traditional stone or brick construction.

Furthermore, the installation of the tie rods in the proposed position should allow the instauration of

even less dangerous kinematic mechanism such the ones proposed in Figure 7-19 (Lagomarsino

et.all, 1997) which are also less likely to occur.

Figure 7- 19: Possible mechanism after the position of the tie rods

7.3. F.E.M Model

To carry out the analysis, we used a FEM model carried out by professor Luis Ramos in 1999 during

his previously studies on St. Torcato church, by using the programme Diana. To have a better

St. Torcato Church



49

knowledge of the behaviour of the structure, the 3D model took into account the main façade and all

the nave. The zone of transept, the latest part of the church to be constructed with different techniques

(in reinforced concrete) has not been considered because it is not connected to main nave, thus it

does not influenced the rest of the structure.

An old version of this programme has been used to elaborate this model and due to this fact we

encountered many warnings that have been repaired in order to be able to modify the original model.

The Finite Element Method model allow both the behaviours linear and non linear of the materials and

the structure modelled is mainly subjected to vertical forces due to the self-weight. In order to imitate

the presumed possible real problem of the structure (settlements of the soil), the model include five

different types of soils which parameters have been evaluated by the civil engineering staff of the

university of Minho2. The characteristics of these kind of soils have been already discussed in chapter

7.2.

In order to simplify the analysis we let the loads to be activated all in the same time, not taking into

account the construction phases the led this part of the church to be constructed in more then 50

years.

The material non linearities introduced in this model are representative of the real behaviour of the

granite: the non linear tensile behaviour has been considered for the material and a reduced value for

the tensile strength of ft = 0.2 MPa and for the Fracture Energy Gf = 0.05 Pa.m. As stated in the

previous report, this low value of Fracture Energy represents a measure of the ductility-frailty ratio of

the material and more precisely, this value represents a material with a high frailty level.

7.4. Phase analysis Starting from the previous F.E.M. model, a phase analysis has been conducted by means of different

models, each of them with slightly difference characteristics.

Bearing in mind that the strengthening of the structure with tie rods is only the second step of the total

strengthening intervention, the basic idea of the phase analysis conducted with the software Diana is

to see what happens in the overall behaviour of the structure if the strengthening of the foundation is

not working properly. This effect has been modelled with a 1% increment step of the actual measured

displacement of the base nodes.

The first pace of the analysis was to evaluate the displacement at the base nodes by using a non

linear analysis that takes into account the interaction soil-structure. For this purpose the original model

has been used, but it needed to be corrected because modelled with a previous version of Diana.

After being adequately revised, the base displacement (settlement) have been tabulated and the crack

pattern by meanings of principal strains (phase 1) is depicted in Figure 7-20:

2 See: “Relatório de prospecção geotécnica junto ao santuário de S.Torcato, Processo LEC 79/97, Laboratório de Engenharia

Civil da Universidade do Minho, Guimarães, 1999”

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Figure 7- 20: Results of the phase 1 by meanings of maximum principal strains (cracks) for: front façade

(top left), back façade (top right), top vault (bottom left), bottom vault (bottom left)

In Phase 1 the loads and the interface elements are activated. Once the actual crack pattern has been

established and (theoretically) the foundation strengthening shows its ineffectiveness, to model the

following step, the reinforcement has been introduced (the command files are reported in the Annex

B).

Phase 2 is used to represent the behaviour of the structure after the application of four stainless steel

tie rods. These new elements are introduced in phase 2 and their positions can be seen in the

following picture. The longitudinal reinforcement cannot be seen clearly because of its superimposition

with the contours’ structure. Transv 1 and Transv 2 are the transversal reinforcement (from bottom to

top) and Long 3 and Long 4 are the longitudinal reinforcement (from left to right) (see Figure 7-21).

Main external crack Main internal

crack

Main crack on the top of the vault

Main crack bottom vault

kPa

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51

Figure 7- 21: Position of the tie roads (assonometric and top view)

Phase 2 is the application of 10 steps for a resultant overall displacement of 10% of the total

displacement resultant from the Phase 1. Thus this assumption takes for granted that after the

strengthening of the foundation the whole structure keeps sinking for a tenth of the overall settlement.

The ten steps procedure is to establish the effectiveness and the stress history of the tie roads.

The actual picture of the width of the main crack of the front façade can be represented by the

following charts (Figure 7-22) that show, by meaning of the integrated area under the curve, the width

of the crack and its opening during the steps of the sinking. In the chart, the distance is the length

between the measured points between which the crack arises, while in the ordinates, the principal

(maximum) strains are reported.

The trend of this crack (Figure 7-23), from the beginning of the sinking behaviour of the structure until

nowadays, is depicted in the following chart. It is important to compare the maximum value found

through the F.E.M. model (approximately 2.1 mm – all the values and charts are reported in the Annex

B) and the real crack width measured in situ: the first is approximately ten times smaller than the

latter. This phenomena could be caused by a not accurate calibration of the model or from the very

quick settlement of the church in the loose soil.

Long 3 Long 4

Transv 1 Transv 2

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ALL Steps

0.0E+00

1.0E-04

2.0E-04

3.0E-04

4.0E-04

5.0E-04

6.0E-04

0 1 2 3 4 5 6distance [m]

ε (P

1)

50% 60% 70% 80% 90% 100%

Figure 7- 22: Main crack widths in the front façade

History of the opening from 0 to 100%

0

0.5

1

1.5

2

0% 20% 40% 60% 80% 100%Steps [%]

wid

th [m

m]

Figure 7- 23: Opening history for the main crack of the front façade (0-100%)

The Phase 1 is the common phase for all the following elaborations.

In Phase 2, in which the ties have been applied, the crack widths have been monitored and the trend

of its behaviour is depicted in Figure 7-24, in which a stabilization can be noticed:

History of the opening from 0 to 110%

0

0.5

1

1.5

2

0 10 20 30 40 50 60 70 80 90 100 110Displacement [%]

wid

th [m

m]

Figure 7- 24: Opening history for the main crack of the front façade (0-110%)

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53

Hereafter some representative steps are depicted to show how the ties behave during the application

of the new load called displacement in the Diana data file.

The stress history for increments from 1% to 10% of the settlement for the tie rods can be shown by

meaning of axial force (Forces in kN, bearing in mind that the section of the tie rods are 35 mm

diameter stainless steel bars). In the first evaluated model, the ties Long 3 and Long 4 have been

(erroneously) inserted from one node in each tower to another node on the other end of the lateral

wall (as shown in Figure 7-25).

Figure 7- 25: End node for Long 4

According to this scheme, the final graphs of the axial load are depicted in the following Figure 7-26:

Axial Force variation

0.0

0.5

1.0

1.5

2.0

2.5

3.0

1 2 3 4 5 6 7 8 9 10

Load increment [%]

Axi

al F

orce

[kN

]

Bar1 Bar2 Bar3 Bar4

Figure 7- 26: Axial load versus increasing load steps of Transv 1 (left) and Transv 2 (right)

Long 3 and Long 4 are mainly unstressed, while Transv 1 and Transv 2 have very low axial force. The

increasing value of the axial load while increasing the settlement was obvious and expected, but the

significance of the results was not. The obtained values are in fact unpredicted first because of the

almost null value for the Long 3 and 4 and latter because they are going in an opposite way with

respect to the limit analysis. But the reason is also obvious: the limit analysis and the F.E.M. model

Truss element

highlighted

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54

are based on different assumptions, the strongest of which is to consider the foundation infinitely stiff

in the first and flexible in the latter. It can be noticed that the longitudinal reinforcements are practically

unstressed, conflicting with the previously hand calculation.

These results are not satisfactory for the strengthening purpose and the reason for these obtained

values can be found in the deformed shape of the structure (Figure 7-27):

Figure 7- 27: Deformed shape due to the loose soil

In the way the tie rods have been modelled they are unloaded because they follow the structure in its

sinking behaviour, not finding any other possible restraint which in reality is borne by the thick and stiff

transept walls.

A further model has been developed by fully clamping the end of the trusses Long 3 and Long 4. A

node within the lateral wall has been selected as restraint and this of course brought high

concentration of stresses that induced big cracks as depicted in the following images by meaning of

principal maximum strains, for each increment of displacement (Figure 7-28 and Figure 7-29):

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55

ALL Steps

-1.0E-03

1.0E-03

3.0E-03

5.0E-03

7.0E-03

9.0E-03

1.1E-02

1.3E-02

0 1 2 3 4 5distance [m]

ε (P

1)

1% 2% 4% 8% 10%

Figure 7- 28: Main crack widths in the arch

Figure 7- 29: Maximum principal strains ε (P1)

The highest value of the crack width at this restraint nodes has been evaluated in about 30 mm and its

dangerous opening behaviour linearly increases with the settlement of the church (Table 2):

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56

History of the opening from 100% to 110%

0

5

10

15

20

25

30

35

100 102 104 106 108 110Displacement [%]

wid

th [m

m]

Phase 2 Step10 110% Area

node X distance Princ strain =position [m] [m] εmax width crack

16511 1.82E+01 0 0.0006770 0.018891316447 2.12E+01 2.98 0.0120000 0.014070516445 2.33E+01 5.02 0.0018000 32.9617 mm Figure 7- 30: Arising crack at the supports and maximum value

All history of the crack opening at this node, by meaning of crack width charts, can be found in the

annex B. To better represent the behaviour of the tie system, a model of the whole church would be

needed. Cause of lack of time and knowledge of the software, to avoid local phenomena as such the

abovementioned high stress at the end of the lateral wall, two fixed nodes has been introduced in the

second phase of the analysis. At each of these two nodes, a tie rod has been anchored (Figure 7-31).

The position of these nodes has been evaluated by determining the actual position of them by

meaning of deformed shape (with “actual” the position after 100% of the settlement is intended).

Figure 7- 31: Deformed shape and maximum principal strains

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57

As it can be seen from the pictures above, the tie rods are restrained in an “imaginary point” outside

the structure; as the F.E.M. model is built only from the façade to the end of the nave, an important

interaction with the transept is missing. In the real situation, the reinforcement placed in the proposed

position would find its fasten right in this element and act as designed.

The introduced nodes try to represent somehow the fixed constraint the walls of the transept would

bring to the nave of the church. In the following Figure 7-32, the axial forces in the tie rods are

depicted:

Axial Force variation

0.0

20.0

40.0

60.0

80.0

100.0

1 2 3 4 5 6 7 8 9 10Load increment [%]

Axi

al F

orce

[kN

]

Bar1 Bar2 Bar3 Bar4

Figure 7- 32: Axial force of the tie rods

With this configurations a maximum force of 105 kN is obtained. This leads to a tensile stress equal to

110 MPa which is less than 220 MPa, yield strength of the selected stainless steel.

The transversal tie rods never showed their effectiveness. The values of axial force found for Transv 1

and Transv 2 never confirm the results of the limit analysis hand calculation. This is mainly due

because while in the first analysis the second highlighted mechanism considered the outwards

splitting of the right tower, with the separation of the macro block from the rest of the church, in the

F.E.M. model is underlined a different behaviour which is the uniformly sinking of the whole structure.

While sinking, the truss element introduced as reinforcement bars just accomplish this behaviour. In

addition, the F.E.M. model also showed a different deformed shape which is the progressive overall

tilting in the west direction as it can be seen in the following picture and in agreement with the

monitoring of the previous report (Figure 7-33).

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Figure 7- 33: Deformation of the church in Y direction

Unfortunately, due to lack of time and sufficient knowledge about the software, a clear result would not

been possible to establish. However, the path has been undertaken, and further elaboration should be

carried out to better investigate the occurring phenomena.

7.5. Truss support strengthening

Minor important damages, but still dangerous in the overall behaviour of the structure, have been

found in the support of the roof trusses (7-34).

Figure 7- 34: Damaged supports and crack pattern

This problem may have been caused by the eccentric reaction of the truss on its support. The trusses

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59

only lie on a small part of the granite wall. This reduced area is confined by a sleeper made with two

roughly shaped pieces of wood. This phenomena may not be related to the deformation due to the

settlements of the structure, but most likely to the concentrated force applied that may had provoked

an overturning moment, as the same crack pattern can be seen in both ends of the structure. Another

possible phenomenon that could have led to this crack pattern is the possible deformation of the truss;

this progressive buckling (Figure 7-35) may have heightened the concentrated forces at the edge of

the supports.

Figure 7- 35: Possible deformation of the truss

The proposed intervention consists in two stainless steel tie rods of 10 mm diameter that will be

inserted in the lateral wall and they will then inject with an epoxy resin. The reaction they are going to

develop will be by meaning of friction within the granite wall. The contrast on the other end will be then

guaranteed by a stainless steel UPN 80 profile.

The strengthening intervention to be made will aim to stabilize the support from the overturning

(Figure 7-36 – the design is reported in the Annex E).

Figure 7- 36: Rendering of the proposed intervention

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60

7.6. Arches strengthening

Other dangerous cracks that arose from the monitoring of the F.E.M. model are the ones that affect

the vault of the main nave. Unfortunately due to the lack of time, no strengthening techniques have

been implemented in the F.E.M. model, but a possible solution is proposed hereafter.

The measurements of the crack in the intrados have been done with Diana and its width is

represented in the followings (Figure 7-37) :

ALL Steps

-1.0E-04

1.0E-04

3.0E-04

5.0E-04

7.0E-04

9.0E-04

1.1E-03

1.3E-03

1.5E-03

0 1 2 3 4 5 6distance [m]

ε (P

1)

50% 60% 70% 80% 90% 100%

Figure 7- 37: Intrados arch crack width

In according with the crack of the main façade, the trend of the fracture is to increase with the

increasing of the settlement but with an higher velocity (Figure 7-38).

History of the opening from 0 to 100% of displacement

0

0.5

1

1.5

2

2.5

3

3.5

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Steps [%]

wid

th [m

m]

Arch intradox Front façade

Figure 7- 38: Comparison of the two main cracks encountered in the structure

The configuration depicted by the model shows the formation of two hinges (Figure 7-39).

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Figure 7- 39: cracks (principal strains) and possible occurring phenomenon

Bearing in mind that after the strengthening of the foundation, the response from the monitoring

system should confirm the inactivity of all the cracks of the structure, hereafter some proposals to

avoid the worsening of the vault condition are evaluated.

Structural members with single curvature generally lose their functionality due to the formation of

hinges that promote the mechanisms of collapse. Hinges form in such masonry structures due to the

negligible tensile strength of the material. The hinges are located in regions of limited contact area,

externally to the mid plane of the vault and, as first approximation, they can be located one at the

intrados and one at extrados of the structural element.

An intervention with FRP can be proposed. As the church is a place of worship and relevant by

meaning of architectonic and artistic value, the intervention cannot be afforded to be on both sides of

the vault, but only on the extrados, where the intervention would not be visible.

FRP materials reinforcement delays both opening of cracks and formation of hinges within the

masonry structure located on the opposite side with respect to the one where the FRP system is

installed. Thus the benefits on the intrados crack could be minimum even though experimental results

may confirm the overall increment of safety for the structural element.

Moreover, the extrados reinforcement allows the arch curvature to be as such to display compressive

stress orthogonal to the FRP reinforcement (not tensile stress orthogonal to the FRP reinforcement

that enhances debonding between FRP and masonry, as when they are in the intrados).

Supplementary analysis and detailed design should be carried out for this technique (especially for

what concerns debonding and accurate anchorage). Cause of lack of time further investigations were

impossible to carry out.

As above mentioned, the proposed procedure has to be carried out only if the strengthening of the

foundation is not effective. Thus, the proposed works for the repairing of the vaults will be first the

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62

repointing of the cracks and then paying attention to the results that the monitoring system installed

will provide. This informations are essential for the better understanding of the modified behaviour

(active or inactive of the vault) and for any further calculation about the structural element.

8. RECOMMENDATION AND MAINTENANCE PLAN

A key factor in building restoration is Continuos monitoring. This could give a clear picture on the state

of the structure before, during and after restoration.

Hence it is proposed to monitor the cracks by constance presence of crack meters for about a year

covering all the different seasons. Monitoring the structure after strengthening for a complete cycle of

all the seasons would give a fare idea of the behaviour of the structure in various environmental

conditions. Later, according to the observations and results from the monitoring system, further period

of monitoring should be decided.

Service loads: environmental and accidental actions may cause damage to structural systems even

after a successful strengthening process. In this context, life long maintenance plays an important

role. Regular inspections and condition assessment of strengthened structures would result with a

programmed repair works and cost-effective interventions in future. Maintenance is essential because

of the cultural importance, the safety of visitors, potential natural risks and the accumulation of

physical, chemical and mechanical damage through time.

With the above objective in mind a monitoring plan for the church after the strengthening of the

structure has to take place as proposed hereafter:

The ELEMENTS to be monitored are:

Roof, Tiles, Penetrations, Timber Truss,

Rain water disposal such as drain pipes, sewage disposal,

Exterior wall surface, stone,

Connections, wall to beam junctions, external carpentry, glazing,

Interior walls, floors and ceilings, vaults, finishes,

Foundations,

Interior carpentry, Interior stairs,

Lightening conductors,

Clocks on the tower.

The PROBLEMS and CONDITION to look for in the above mentioned elements:

Cracks, loosening of pointing – Presence of any of this condition is a hint to a possible structural

movements

Dampness and water seepage marks – Sign of missing core, weakening water proofing course,

structural movement and such related problems

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63

Scaling or chipping of the materials – Material deterioration is a sign of degradation of the

material’s strength, parts under compression, creep etc.,

Leaching, colour change, patch marks – Chemical changes in material could be the preliminary

step to the reduction in strength of the material,

Relative humidity, temperature, light intensity – plays a vital role in preservation of the internal

artefacts, paintings etc., presence of condensation in some cases

Biological growth like vegetation, algae, fungi, etc., - conditions leading to material deterioration

Insect attacks like termite, bores etc., - Conditions leading to material deterioration

Addition of new material, object, etc., - many times it would be the cause of some localized

damages,

Change in use of the space leading to damage of the structure – Unplanned change in use could

lead for a structural damage.

Theft and vandalism.

There is also a LIST OF RECOMMENDATIONS for future healthier state of the church:

The spaces within the church may not be used as a space for storage for heavy items, without any

prior consent from the structural advisors.

Existing cracks and open joints shall not be covered with any kind of plaster or painted over for a

period until one year after the strengthening takes place. The church authorities shall consult the

concerned professional for carrying out such work after one year when the extended monitoring

period is completed successfully without any discrepancies.

No plasterwork or paintings to be done over any new cracks open joints etc., in the future. This

would let the visual inspection by the expert team who is looking for any problems.

No metal clamps nails or any such materials are to be clamped on to the wall surfaces.

The PVC pipes used as rain water pipes needs to be replaced with a better aesthetically

appealing solution, which would create no water seepage marks on the exterior walls and

eventually create any structural problems.

Provide bird repellers on the openings of the church to stop birds from entering the structure. This

would save the church interiors from the material deterioration, which might take place by the

presence of the excreta.

In later period, if any stone cleaning for the surfaces are recommended, it is proposed to use a

method which would not deteriorate, degradate or leave a stain on the material.

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64

9. CONCLUSIONS

A key role for the interventions on the St. Torcato church is played by the monitoring phase.

The monitoring system will be the “doctor” of the church and will better identify the pathologies

that are affecting the structure. Hence we conclude by saying that a vigirous monitoring of the

structure before, during and after the strengthening would give a clear picture on the structure

movements and condition of the structure. This monitoring would lead to a economic

strengtheing design and minimal intervention which is a vital phenomenon for any succesfulful

Heritage sterngthening project.

Micropile is most suitable for the foundation strengthening technique for historical building

among the three commonly used techniques, namely, foundation enlargement, grouting and

micropiling. A preliminary design using micropile for strengthening the foundation of church

including the length, inclination and location of the micropile is proposed on the assumption of

end bearing load transfter principle. However, due to lack of necessary geotechnical

information, the design is only preliminary one. To facilitate a more realistic and efficient

design, a complete soil exploration test is necessary for understanding the mechanical

properties of soil in different layers.

Limit analysis is a powerful tool for the detection of the most dangerous and likely kinematism

that may lead a structure to collapse. However, it might not have been enough for the

analysis, since the soil/structure interaction plays a fundamental role. Nevertheless, it was

useful to evaluate the seismic safety of the structure.

Furthermore, a F.E.M model was used to evaluate the strengthening with tie-rods. Due to the

lack of time, this analysis was incomplete. Therefore the obtained results showed as

inadequacy the proposed intervention, although it is rational to add tie-rods. This might be due

to the not high probability of the supposed phenomenon to occur (uniform and steady

settlement of the whole church). More complete and realistic analysis should be carried out,

such us modelling concentrated settlements only in some parts of the church (e.g. settlement

of the nave, while the soil beneath the façade is rigid), followed by the accurate result

analysis. A complete model of the church shall also be carried out, including the transept part.

Based on the FEM analysis, the proposed ties might not be suitable especially for holding

together the two towers as their movement is in the same direction rather than spreading

apart. But for safety reasons, in the strengthening design it was considered two parallel tie-

rods. They will be active if differential settlements will occur between the towers.

The foundation stabilization will be the major action to prevent the increasing of damage in the

arches (nave vault). However, the proposed technique of FRP’s strengthening may enhaced

their overall strength even if the intervention at the soil would not display its design capacity.

Further evaluation on typologies, correct positions and quantities should be correctly

evaluated

St. Torcato Church



65

Regarding the method to be adopted for repairing the cracks, a continious monitoring is a

must as mentioned earlier in the report. After a vigorous monitoring if the structure is declared

by team of experts to be safe and the settlement have stabilized, it is proposed that the cracks

be examined again. After re-examination, it is proposed only to re-point or fill the cracks with

suitable mortar of suitable strength, so the cracks doesnot lead to vegetation growth, leaching

and such other problems which would lead to further structural damage. Hence it is proposed

to let the cracks be visible to speak about the disstres the structure had undergone in the

past.

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66

10. REFERENCES

- A.Giuffrè, C. Carocci, “Codice di pratica per la sicurezza e la conservazione del centro storico

di Palermo”, Palermo, Laterza, 1999

- L.Baruchello, G. Assenza, “Diagnosi dei dissesti e consolidamento delle costruzioni”, Roma,

Dei, 2004

- “Design manual for the structural Stainless Steel”, Euroinox The European Stainless steel

Development Association, Building Series, Vol. 3, 2002

- S. Mastrodicasa, “Dissesti statici delle strutture edilizie”, Milano , Hoepli, 2003

- A. Giuffrè, “Sicurezza e conservazione dei centri storici- Il caso Ortigia”, 1993, Laterza editore

- SAHC 2007/2008 lectures, Unit SA3



- S. Lagomarsino, S. Brun, S. Giovinazzi, C. Idri, A. Penna, S. Podestà, S. Resemini, B.Rossi,

“Modelli di calcolo per il miglioramento sismico delle chiese”

- S. Lagomarsino, “A new methodology for the post-earthquake investigation of ancient

churches”, 11th European Conference on Earthquake Engineering © 1998 Balkema,

Rotterdam

- “Studio per la vulnerabilità sismica degli edifici pubblici, strategici e di culto nei Comuni colpiti

dal sisma del 31 ottobre 2002; Linee guida per gli interventi di riparazione del danno e

miglioramento sismico per gli edifici di culto e monumentali - EDIFICI DI CULTO” , Decreto del

Commissario delegato n.29 del 6.8.03

- L. Ramos, R. Aguilar, “Dynamic identification of St. Torcato’s Church: Preliminary tests”,

Guimaraes, 2007

- Miloš Drdácký, "Structural and Material Health Monitoring of Historical Objects: Situation in

the Czech Republic" Sensing Issues in Civil Structural Monitoring, Springer Netherlands,p127-

133, 2005

- Rai, Gurmeet. Deasarkar, Paromita, Technical Manual on Lime mortars, INTACH, 2005

- P. B. Lourenço, L. Ramos “Investigação sobre as patologias do Santuário de São Torcato”,

Departamento de Engenharia Civil, Universidade do Minho, 1999.

- Magnum Piering Inc., “Maginum Steel Push Pier TM Technical Reference Guide”, May, 2004.

- US Department of Transportation Federal Highway Administration, “Micropile Design and

Construction Guidelines”, June, 2000.

- E. CY YIU, “Foundation Repair: Underpinning”, Lecture Notes of Construction IV, University of

Hong Kong, January, 2007, Hong Kong

- Gue and Partners Sdn. Bhd. “Micropile Specification”, September, 2006.

- http://www.foundationtechnologies.com/

St. Torcato Church



67

- http://www.helicaldrilling.com/

- www. soil.co.uk

- www.slopeindicator.com

- www.gill.co.uk/products/anemometer/anemometer.htm

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68

ANNEX A – Conditions mapping Observation on defects

GRID & SPACES considered:

Flooring cracks

Ground Level Flooring Cracks: There are cracks found running north south on the floor at the entrance of the building at grid A, C

and E.

The width of the crack is about 3mm.

These are old cracks which have been cement pointed.

The cement pointing seems to be loosening out from its position (sign of active settlement)

Entire flooring grid A and E has been cement pointed for its open joints.

The grid B shows partly open joints on the flooring stones.

Few stone members at grid C - the middle grid show open joints along north south direction.

A B C D E

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69

First Level Flooring Cracks: There are three main cracks found running north south on the floor of grid C.

The width of the crack is about 10 - 15mm.

These wide old cracks have been cement pointed.

The cement pointing seems to be loosening out from its position. (Sign of active settlement )

These cracks extend on to the balcony stone railing and the walls of this floor.

A B C D E

A B C D E

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70

Second Level Flooring Cracks: This level has the vault of the nave. There are some plaster marks seen in the

east west direction at the junction where the vault meets the wall.

The flooring to the south of grid B, C and D as one goes outside the structure

shows severe cracks running north south at the small passage.

This crack is about 5-10 mm wide.

The crack extends on both the side walls.

There is a crack seen in the inner side of the corridor where the vault meets the

wall surface. This crack could be coz of the difference in material. This crack has been plastered

in cement.

Ceiling cracks

Ground level Ceiling Cracks: Grid A:

The staircase landing at the west of this grid shows open joint. This crack can be traced along the

voussoir stones of the arch at the door to grid B.

Grid B:

The ceiling of the grid B shows continuous cracks at the centre running east west. The

continuation of this crack can be seen along the arch until the staircase landing of grid A.

Middle bay Grid C:

Three cracks are seen along grid C along north south direction along the stone joint direction. All the cracks show repair works in cement plaster.

The cracks to the east and the west are active. We can see the cracks developing over the cement plaster and the cracks are of 2 mm wide.

A

B

C

D

E

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71

Grid D: The ceiling of the grid B shows two continuous cracks running east-west. The continuation of

these cracks can be seen along the arch until grid E.

Grid E:

The staircase landings at east and west shows open joints which continuous until the arch window

opening on the west wall of this grid. This long crack is a continuous one from the grid D which

runs along the arch opening, walls and the staircase soffit until the arch window on the west wall

of grid E.

First level Ceiling Cracks: This floor level ceiling is well plastered and rendered and shows no

cracks.

There are stone bands in between shows open joints in the north

south direction along the stone joints.

Second Level Ceiling Cracks: The corridor ceiling of this level shows several open joints.

There is vegetation growth seen at these open joints.

There is also water seepage through these open joints.

External walls cracks

East Wall ELEVATION: Continuous open joints and cracks (of < 5mm wide) to the centre of the wall starting from the

plinth up to a height of 6mts are found.

Cracks on grid C Cracks on grid D

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72

Few cracks are found splitting the material and rest other cracks are found along the stone joints.

Cracks splitting stone Cracks splitting stone

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73

Cracks

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74

South Wall - Outer Layer: Shows cracks on the entire wall surface springing from the arch voussoir stones until the

colonnade and the entablature in a diagonal pattern.

Wider cracks are found around the openings - the rose window, the main arch door opening,

entablature and the colonnade crushing the stone members.

The width of the cracks on this façade varies from 10mmm to 60mm.

The front façade is heavy damaged due to the cracks.

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75

West wall: there are three types of cracks observed on this wall,

namely wide open joints/ cracks, hairline open joints / cracks and

compression cracks.

Continuous wide open joints / cracks:

Continuous cracks starting from the bottom of the plinth (6mm

wide) until 6.1m height. The cracks are mostly along the stone

joints.

Hairline cracks:

Continuous cracks starting from the bottom of the arch window

at level 1 (<3mm wide) until 9m height. The cracks are mostly

along the stone joints.

Compression cracks:

There are some minor crushing cracks on the stone are found

at a height of about 5m from the ground towards the south end of this wall

Crushin

Hair

line

k

Wide

cracks

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76

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77

Internal wall cracks

South wall Inner layer:

This part of the wall is the inner skin creating corridor towards the south.

This wall also shows severe cracks and open joints on the wall surface.

Ground level: here there are cracks seen just above the arch

First Level: There are multiple cracks seen on the entire length of the wall. The cracks branch into

two above the opening. The cracks are pointed in cement.

Second level: there are multiple cracks seen at this level. Many of them have been cement

plastered, the year marked is 1988. The west side crack which runs for the entire height of the

wall looks clean and fresh. This is a crack of about 8mm wide. The entire stone wall surface looks

disfigured / damaged. There is also a wide crack plastered at the junction where the vault meets

the wall.

St. Torcato Church



78

Left: First level cracks seen on the ceiling

and the vaulted roof.

Right: First level: Cracks seen branching out

above the rose window.

Above: first level: closer view of the

cracks above the rose window

Above left: First level entire south

wall with the cracks.

Above Right: First level relative

cracks on the floor of the same

level

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79

ANNEX B – Strengthening & Dynamic Identifications

Limit analysis calculations: overturning around base hinge-simplified approach

b4 = 1 m Tower roof on N3 P = 587 kN( 28.25 kN/m on every single of the four walls of the tower)

3 h4 = 8 m Landing of stairs on N2 259.2 kN( 9.00 kN/m in each wall)Roof of the main nave

b3 = 1.4 h3 = 10 m (3.6 kN/m on each wall)2 T For the landing of the stairs on N2

b2 = 1.4 h2 = 19 m Roof's nave 1 kN/m2

γ = 25 kN/m31.4 m

1 h1 =4.4 m

b1 = m

N1 = 20 kN W1 = 169.4 kN d1 = 1.027 mN2 = 20 kN W2 = 651 kN d2 = 0.933 mN3 = 19 kN W3 = 350 kN d3 = 0.933 mN4 = 21 kN W4 = 200 kN d4 = 0.667 m

alfa 0 = 0.035 ∆ xN4 = 1 m∆ xW4 = 0.902 ∗∆ xN3

M* = 1102.01 kN/g ∆ xN3 = 0.805 ∗∆ xN3

112.33 kN ∆ xW3 = 0.683 ∗∆ xN3

∆ xN2 = 0.561 ∗∆ xN3

∆ xW2 = 0.334 ∗∆ xN3

fraction of the mass participant e* = 0.760 ∆ xN1 = 0.107 ∗∆ xN3

to the kinematism ∆ xW1 = 0.054 ∗∆ xN3

spectral acceleration a0* = 0.45 m/s20.046 g

Verification with "linear" analysis (ULS)0.093 g

ag = 0.08 gS = 1.35q= 2

Z = 19.66 m Z/H = 0.4796H = 41.0 m

Momento attorno ad B:Posizionamento di T in cima al secondo livello

alfa 0= N3 = 18.5142857 kN ∆ xN4 = 1 mW3 = 350 kN ∆ xW4 = 0.778 ∗∆ xN3

N4 = 20.9642857 kN ∆ xN3 = 0.556 ∗∆ xN3

W4 = 200 kN ∆ xW3 = 0.278 ∗∆ xN3

1.54

Not Verified

0.0736

calculation of the

partecipant mass

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80

Limit analysis calculations: overturning around base hinge

b4 = 1 m N1 = 20 kN d1 = 1.027 m

N2 = 20 kN d2 = 0.933 m3 h4 = 8 m N3 = 18.5 kN d3 = 0.933 m

N4 = 21.0 kN d4 = 0.667 mW1 = 169.4 kN

b3 = 1.4 h3 = 10 m W2 = 651 kN2 T W3 = 350 kN

b2 = 1.4 h2 = 19 m W4 = 200 kN

1.4 m ∆ xN4 = 1 m1 h1 =4.4 m ∆ xW4 = 0.902 ∗∆ xN3

∆ xN3 = 0.805 ∗∆ xN3

alfa 0 = 0.095 ∆ xW3 = 0.683 ∗∆ xN3

b1 = m ∆ xN2 = 0.561 ∗∆ xN3

∆ xW2 = 0.334 ∗∆ xN3

σc = 1 Mpa ∆ xN1 = 0.107 ∗∆ xN3

t1 = 0.97 m ∆ xW1 = 0.054 ∗∆ xN3

t2 = 0.84 m t3 = 0.39 m t4 = 0.15 m

M* = 1102.01 kN/g 112.335 kN

fraction of the mass participant e* = 0.760to the kinematism

spectral acceleration a0* = 1.22 m/s2 0.125 g

Verification with "linear" analysis (ULS) 0.093 g

ag = 0.08 gS = 1.35q= 2

Z = 19.66 m Z/H = 0.48H = 41.0 m

1.54

Verified

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81

Limit analysis calculations

First mechanism:

t1 = 1.88 mdt = 3.7 m N = P = 500 kN

alfa 0 = 0.186 d1 = 10.56 m P= W = 45009 kNd2 = 7.6 m t = 4.2 m

γ = 25 kN/m3 Pt = 33825 kN λ = 0.08rea tower = 33 m2 P1= 8125 kNH tower = 41 m P2= 3059 kN M = 85357.46 kNm

M = P*0.75L + WL/3 + qH - λ (PH + QH + WH2/3)Area 1 = 130 m2 total barycentre H = 15.58 m N = 45509 kN N = P + Wthickness = 2.5 m barycentre h of tower = 20.27 m u = 1.876 m u = M/NArea 2 = 92 m2 barycentre 2 = 10.46 m σ = 3851.35 kN/m2 σ = 2N/(3 u t)thickness 1.33 m barycentre 1 = 10.53 m 3.78 Mpa

between 2 and 5 MPa

calculation of the partecipant mass M* = 42611.49 kN/g 4343.679 kN




Security factor: 3.13ag = 0.08 gS = 1q= 2

Z = 15.58 m Z/H = 0.38H = 41.0 m

Verified Second mechanism:

t1 = 1.84 mdt = 3.7 m N = P = 500 kN

alfa 0 = 0.184 d1 = 10.24 m P= W = 43809 kNd2 = 7.8 m t = 4.2 m

γ = 25 kN/m3 Pt = 33000 kN λ = 0.08 da assumererea tower = 33 m2 P1= 7750 kNH tower = 40 m P2= 3059 kN M = 81794.34 kNm

M = P*0.75L + WL/3 + qH - λ (PH + QH + WH2/3)Area 1 = 124 m2 total barycentre H = 15.85 m N = 44309 kN N = P + Wthickness = 2.5 m barycentre h of tower = 20.24 m u = 1.846 m u = M/NArea 2 = 92 m2 barycentre 2 = 11.14 m σ = 3809.96 kN/m2 σ = 2N/(3 u t)thickness 1.33 m barycentre 1 = 10.53 m 3.74 Mpa

between 2 and 5 MPa

calculation of the partecipant mass M* = 41737.08 kN/g 4254.544126




Security factor: 2.24

ag = 0.08 gS = 1.35q= 2

Z = 15.85 m Z/H = 0.40H = 40.0 m

Verified

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82

Third mechanism:

t1 = 1.58 mdt = 5 m N = P = 500 kN

alfa 0 = 0.164 d1 = 1.23 m P= W = 87818 kNd2 = 9.8 m t = 11.6 m

γ = 25 kN/m3 Pt = 66000 kN λ = 0.08 da assumeretowers 66 m2 P1= 15700 kN

H tower = 40 m P2= 6118 kN M = 138606.8 kNmM = P*0.75L + WL/3 + qH - λ (PH + QH + WH2/3)

nt façade = 314 m2 total barycentre H = 16.8 m N = 88318 kN N = P + Wthickness = 2 m barycentre h of tower = 20.7 m u = 1.569 m u = M/N

Area 2 = 184 m2 barycentre 2 = 13.9 m σ = 3234.18 kN/m2 σ = 2N/(3 u t)thickness 1.33 m barycentre 1 = 10.53 m 3.17 Mpa

between 2 and 5 MPa

calculation of the partecipant mass M* = 84980.80 kN/g 8662.67 kN




Security factor: 1.93

ag = 0.08 gS = 1.35q= 2

Z = 16.80 m Z/H = 0.42H = 40.0 m

Verified

Fourth (local) mechanism

γ = 25 kN/m3

roof = 73.125 kN VerticaleP = 3313 kN Verticale

h roof = 8.17 mhg = 4.21 m

alfa 0 = 0.205

M* = 339.082

8.17

4.21 ∆x1 = 1 m1.72 ∆x0 = 0.515 m

e* = 0.982 m

18 m

a0* = 2.042 m/s2 0.208 g

ULS verification 0.123 gVerified

church

St. Torcato Church



83

Other possible failure mechanism after tie strengthening

= 2.197447 °

Rotation of the block above with respect to the block below:

Considering the density of the granite equal to:γ = 25 kN/m3

The overall weigth of the two bodies divided by the hingethat can arise is:P tot = 833.75 kNP1 = 572.9951 kN

ψ = 1 P2 = 260.7549 kNN = 589.4786 kN

h1 = 15.80676 mh2 = 7.19324 mB = 1.45 mH = 23 m

Principle of the Virtual Works: δ 1Y = 0.725 mδ 1X = 7.903 mδ 2Y = 3.043 mδ 2X = 7.903 mδ NY = 3.043 m

α = 0.4557 > 0.08 g

x = 3.197447

Verified

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84

Crack widths

Main crack width in the front façade

Crack width 50%

0.0E+00

1.0E-04

2.0E-04

3.0E-04

4.0E-04

5.0E-04

6.0E-04

0 1 2 3 4 5 6distance [m]

ε (P

1)

Crack width 60%

0.0E+00

1.0E-04

2.0E-04

3.0E-04

4.0E-04

5.0E-04

6.0E-04

0 1 2 3 4 5 6distance [m]

ε (P

1)

Crack width 70%

0.0E+00

1.0E-04

2.0E-04

3.0E-04

4.0E-04

5.0E-04

6.0E-04

0 1 2 3 4 5 6distance [m]

ε (P

1)

Crack width 90%

0.0E+00

1.0E-04

2.0E-04

3.0E-04

4.0E-04

5.0E-04

6.0E-04

0 1 2 3 4 5 6distance [m]

ε (P

1)

Phase 1 Step1 50% Area node X distance Princ strain =

position [m] [m] Pmax width crack11977 0.70 0.00 0.00000939 2.19765E-0511972 1.40 0.70 0.00005340 5.66500E-0511960 2.50 1.80 0.00004960 4.85100E-0511961 3.60 2.90 0.00003860 2.42162E-0511985 4.28 3.58 0.00003260 3.18550E-0512023 5.43 4.73 0.00002280 2.01510E-0512016 6.59 5.89 0.00001190 0.2034 mm





Crack width 80%

0.0E+00

1.0E-04

2.0E-04

3.0E-04

4.0E-04

5.0E-04

6.0E-04

0.00 1.00 2.00 3.00 4.00 5.00 6.00distance [m]

ε (P

1)





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85

Crack width at the end of the lateral wall when fixed restraint is applied

Crack width 108%

0.0E+00

2.0E-03

4.0E-03

6.0E-03

8.0E-03

1.0E-02

1.2E-02

0 1 2 3 4 5 6distance [m]

ε (P

1)

Crack width 102%

0.0E+00

2.0E-03

4.0E-03

6.0E-03

8.0E-03

1.0E-02

1.2E-02

0 1 2 3 4 5 6distance [m]

ε (P

1)

Crack width 104%

0.0E+00

2.0E-03

4.0E-03

6.0E-03

8.0E-03

1.0E-02

1.2E-02

0 1 2 3 4 5 6distance [m]

ε (P

1)

Crack width 101%

0.0E+00

2.0E-03

4.0E-03

6.0E-03

8.0E-03

1.0E-02

1.2E-02

0 1 2 3 4 5 6distance [m]

ε (P

1)


position [m] [m] Pmax width crack16511 18.23 0 0.0000409 1.308E-0316447 21.21 2.98 0.0008370 9.199E-0416445 23.25 5.02 0.0000652 2.2281 mm



Phase 2 Step 4 104% Area node X distance Princ strain =


Phase 2 Step 8 108% Area node X distance Princ strain =



position [m] [m] εmax width crack16511 18.23 0 0.0006770 1.889E-0216447 21.21 2.98 0.0120000 1.407E-0216445 23.25 5.02 0.0018000 32.9617 mm

Crack width 110%

0.0E+00

2.0E-03

4.0E-03

6.0E-03

8.0E-03

1.0E-02

1.2E-02

0 1 2 3 4 5 6distance [m]

ε (P

1)

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86

Truss support strengthening

span = 5.35 mWeight of the roof:

Truss = 0.3 kN/m2

Secondary beams = 0.15 kN/m2

battens = 0.13 kN/m2

tiles = 0.45 kN/m2

total = 1.03 kN/m2

Load on the truss: 5.51 kN/m

Length = 10.5 m

F = Reaction = 28.93 kN

Original support dimensions:b = 0.4 mh = 2 m

support Area = 0.8 m2

Reduced support dimensions:b = 0.4 mh = 0.2 m

support Area = 0.08 m2

The compressive stress with the truss lying on the whole support:σc = F/A = 0.036 MPa

Instead the compressive stress isσc = F/A = 0.362 MPa

The steel beam selected is a UPN 80 which W = 26.5 cm3

On this element, considering the two ties rods as supports, a distributed force act and the resultant maximum moment (in the middle of the span) is 1.45 kNmThe resultant stress is then f y = M/W = 184.62 MPa < 220 MPa

Force acting on the tie rods: 14.5 kNConsidering a 10 mm diameter (Area of 0.785 cm2)

The tensile stress of each tie rod is = 0.18 MPa < 220 MPa

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87

Dynamic identification

Annex B- 1: Test in the Tower: (a) measuring points and (b) setups description The sensors disposal allows

distinguishing the bending modes shapes from the torsion mode shapes.

Annex B- 2: Measuring works in the right tower: (a) typical node; and (b) DAQ system (c) balcony setup

Annex B- 3: Scheme of works in the front facade: plan view

Sampling and acquisition

For all measured points and on each test setup, 10 minutes of data were acquired and stored in an ASCII file. The

sampling frequency was 2000 Hz. For data processing, output-only estimation techniques were chosen. In the

study proposed by Prof. Luis Ramos and PhD Rafael Aguilar, the Stochastic Subspace identification method

(SSI/Ref) was used (Peeters and De Roeck, 1999). This method is implemented in the tool MACEC from the

Catholic University of Leuven. This time domain method is robust and allows modal parameter estimation with

high frequency accuracy.

The formulation and the processing will be skipped in this Report and for more information we suggest the reader

to consult a previous report3.

3 Dynamic Identification of St. Torcato’s Church: Preliminary Tests Luís. F. Ramos, Rafael Aguilar, December 2007

St. Torcato Church



88

To obtain better results , it was decided to study only frequencies below 5 Hz. This was done by decimating the

original data by a factor of 200.

Left Tower (Bell Tower)

A problem encountered during the measurements was the presence of the bells in the left tower (Tower bell); To

better treat the output results of the measurements the possibility of having the bells ringing has been considered

and it was decided to analyze the data in two different conditions: the first one just before the bells’ ring and the

second one considering the effect of the rings. By converting the data from time domain to frequency domain, the

procedure led obtaining the Power Spectral Density (PSD) function which gives a first idea of the values that are

most representative of the natural frequencies. Figure B-4 shows the PSD of Setup 1 for the bell tower (left tower).

As it can be seen in the figure, there is a first group of frequencies between 2 and 4 Hz and a second group

between 8 to 22 Hz.

Annex B- 4: PSD of setup 1 – Left Tower

Right Tower

In the case of the right tower, the recorded signals were not contaminated with the bells’ ringing, and so for the

statistical analysis it was decided to take into account the whole signal length. Once again, low level of excitation

during the measuring period was recorded, with an acceleration peak around 2 mg. Figure B-5 presents the PSD

of the Setup 1. As could be observed in the case of the left tower, there are two groups of frequencies: the first

one corresponds to frequencies between 2 and 4 Hz and the second group between 8 Hz to 22 Hz.

Annex B- 5: PSD of setup 1 – Right Tower

Front Façade

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89

Figure B-6 presents the PSD of the acquired signal. It is possible to observe that there are a significant number of

consecutives peaks starting from 2 Hz.

Annex B- 6: PSD of setup 1 – Front Façade

Diana Command files for phase analysis

PHASE 1: *FILOS INITIA *INPUT *PHASE BEGIN ACTIVE ELEMENT STRUCTURE :TO ACTIVATE ONLY THE ELEMENTS OF THE SUPERSTRUCTURE END ACTIVE *NONLIN BEGIN EXECUT LOAD STEPS EXPLIC SIZES 0.5(1) 0.1(5) :SIZE OF THE STEPS TO LET THE ANALYSIS CONVERGE QUICKER BEGIN ITERAT NO LOSS OF ACCURACY OCCURED BEGIN CONVER DISPLA OFF ENERGY TOLCON 0.001 FORCE OFF END CONVER LINESE MAXITE 100 METHOD NEWTON MODIFI : NEWTON RPHSON MODIFIED METHOD FASTER END ITERAT END EXECUT BEGIN OUTPUT FILE "Phase1" : NAME OF THE FAMVIEW FOR PHASE 1 DISPLA INCREM TRANSL GLOBAL : QUANTITIES ASKED TO DIANA TO BE EVALUATED DISPLA TOTAL TRANSL GLOBAL STATUS CRACK STRAIN TOTAL GREEN GLOBAL SMOOTH STRESS TOTAL CAUCHY GLOBAL SMOOTH STRESS CRACK CAUCHY LOCAL END OUTPUT BEGIN OUTPUT TABULA FILE "displacement_1" : NAME OF THE OUTPUT FILE IN WHICH THE DISPLACEMENT OF THE BEGIN LAYOUT SUPPORTS HAVE BEEN STORED TO BETTER CHECK THE DIGITS RESULT 10 BEHAVIOUR OF THE STRUCTURE LINPAG 5000 END LAYOUT SELECT NODES INT : SET OF THE GROUP FOR WHICH THE DISPLACEMENT HAVE BEEN DISPLA TOTAL TRANSL GLOBAL ASKED END OUTPUT *END

PHASE 2 *INPUT READ APPEND FILE="displacement.dat" TABLE LOADS : NEW LOAD APPLIED FOR THE PHASE 2 FROM 100 TO 110% OF READ FILE="new_supports.dat" TABLE SUPPOR DISPLACEMENT *PHASE BEGIN ACTIVE ELEMENT STRUCTURE TRUSS : THE STRENGTHENING TIE RODS ARE ACTIVATED

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END ACTIVE *NONLIN BEGIN EXECUT BEGIN START INITIA STRESS PHASE STEPS EXPLIC SIZE 0.01(10) : STEPS TO INCREMENT THE ORIGINAL SETTLEMENT OF 10% LOAD LOADNR=2 END START BEGIN ITERAT BEGIN CONVER DISPLA OFF ENERGY TOLCON 0.001 FORCE OFF END CONVER LINESE MAXITE 100 METHOD NEWTON MODIFI END ITERAT END EXECUT BEGIN OUTPUT FILE "Phase2" DISPLA INCREM TRANSL GLOBAL DISPLA TOTAL TRANSL GLOBAL STATUS CRACK STRAIN TOTAL GREEN GLOBAL SMOOTH STRESS TOTAL CAUCHY GLOBAL SMOOTH STRESS CRACK CAUCHY LOCAL STRESS FORCE GLOBAL : NEW QUANTITES TO EVALUATE THE FORCES ACTING ON THE TIES END OUTPUT BEGIN OUTPUT TABULA FILE "displacement_2" : STORAGE OF THE NEW DISPLACEMENT FOR THE BASE BEGIN LAYOUT (COUNTERCHCEK) DIGITS RESULT 10 LINPAG 5000 END LAYOUT SELECT NODES INT DISPLA TOTAL TRANSL GLOBAL END OUTPUT *END INITIAL.dat file KEYWORDS: PRE:FEMGEN

FEMGEN MODEL : BETA

'COORDINATES'

1 6.59167E+00 2.12108E+01 2.68550E+01

... omissis …

18016 2.50000E+00 1.77499E+01 2.68550E+01

'ELEMENTS'

CONNECTIVITY

2246 CHX60 12633 12636 12632 12637 12634 12639 12635 12638 12641 12640

… omissis …

377 CQ48I 2444 2463 2402 2405 2401 2467 2443 2447 2452 2465

3154 L6TRU 4835 8112 : TIE RODS MODELLED AS TRUSS ELEMENTS

3155 L6TRU 4346 7624

3156 L6TRU 4915 16447

3157 L6TRU 8277 16948

GEOMETRY

/ 3154-3157 / 1

MATERIALS

/ 35-70 77-82 90-95 128-159 165-169 175-179 394-2462 2464-2863 2865-3105

3107-3137 3139-3153 / 1

/ 180-215 / 2

/ 216-238 / 3

/ 239-250 / 4

/ 251-273 / 5

/ 274-309 / 6

/ 310-317 / 7

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/ 318-325 / 8

/ 326-327 / 9

/ 328-335 / 10

/ 336-337 / 11

/ 338-343 / 12

/ 344-351 / 13

/ 352-359 / 14

/ 360-361 / 15

/ 362-369 / 16

/ 370-371 / 17

/ 372-377 / 18

/ 3154-3157 / 19

::::::::::::::::::

'MATERIALS'

1 YOUNG 1.500000E+07 : CHARACTERISTIC OF THE GRANITE

POISON 2.000000E-01

DENSIT 2.500000E+00

crack 1 : INDICATES CONSTANT STRESS CUT OFF

crkval 200. :TENSILE STRENGTH Ft = 0.2 MPa

tensio 1 : INDICATES LINEAR TENSION

SOFTENING

tenval 0.002 : IS THE ULTIMATE STRAIN EPS U OF THE DIAGRAM

taucri 1 : INDICATES CONSTANT SHEAR RETENTION

beta .5 : FACTOR 0<beta<0.999

2 DSTIF 3900. 1620. : CHARACTERISTICS OF THE SOIL

DENSIT 1.000000E-10

3 DSTIF 5120. 2130.

DENSIT 1.000000E-10

4 DSTIF 8430. 3510.

DENSIT 1.000000E-10

5 DSTIF 6140. 2560.

DENSIT 1.000000E-10

6 DSTIF 6240. 2600.

DENSIT 1.000000E-10

7 DSTIF 9360. 3900.

DENSIT 1.000000E-10

8 DSTIF 19760. 8230.

DENSIT 1.000000E-10

9 DSTIF 54990. 22910.

DENSIT 1.000000E-10

10 DSTIF 45650. 19020.

DENSIT 1.000000E-10

fricti

frcval 0. 0.75 0.0

11 DSTIF 98530. 41050.

DENSIT 1.000000E-10

fricti

frcval 0. 0.75 0.0

12 DSTIF 84620. 35260.

DENSIT 1.000000E-10

fricti

frcval 0. 0.75 0.0

13 DSTIF 14970. 6240.

DENSIT 1.000000E-10

14 DSTIF 18210. 7590.

DENSIT 1.000000E-10

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15 DSTIF 42920. 1788.

DENSIT 1.000000E-10

16 DSTIF 32850. 13690.

DENSIT 1.000000E-10

fricti

frcval 0. 0.75 0.0

17 DSTIF 67530. 28140.

DENSIT 1.000000E-10

fricti

frcval 0. 0.75 0.0

18 DSTIF 56150. 23400.

DENSIT 1.000000E-10

fricti

frcval 0. 0.75 0.0

19 YOUNG 2.000000E+08 : CHARACTERISTIC OF THE STAINLESS STEEL

POISON 3.000000E-01

DENSIT 7.815000E+00

YIELD VMISES

YLDVAL 2.2000E+05

HARDEN WORK

'GEOMETRY'

1 CIRCLE 0.035 : DIAMETER OF THE TIE RODS

'GROUPS'

ELEMEN

1 BAR1 / 3154 /

2 BAR2 / 3155 /

3 BAR3 / 3156 /

4 BAR4 / 3157 /

5 TRUSS / 3154-3157/

'SUPPORTS'

/ 873-880 889-893 899-906 915-919 925-929 935-939 945-949 955-959

'LOADS'

CASE 1

ELEMEN

/ 905 /

FACE ETA1

DIRECT 2

FORCE -43.6800

…omissis…

WEIGHT

2 -10.0000

'DIRECTIONS'

1 1.000000E+00 0.000000E+00 0.000000E+00

2 0.000000E+00 1.000000E+00 0.000000E+00

3 0.000000E+00 0.000000E+00 1.000000E+00

'END'

TABLE LOADS “Displacement” input file

'LOADS' :DISPLACEMENTS OBTAINED FROM THE INTERFACE

:DISPLACEMENT INCREASE OF 100% ELEMENTS (100% - CONFIGURATION CASE 2

DEFORM AFTER PHASE 1)

873 TR 1 0.00E+00

874 TR 1 0.00E+00

…omissis… 2467 TR 3 0.00E+00 2468 TR 3 2.72E-03

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'END' TABLE SUPPORTS “new_supports” input file 'SUPPORTS' / 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 : NEW SUPPORTS (DIANA DOES NOT ALLOW TO ASSIGN DISPLACEMENT TO NODES WHICH ARE NOT CARRYING THE SUPPORTS (AS THE TOP FACE NODES OF THE INTERFACE ELEMENTS) …omissis… 2460 2461 2462 2463 2464 2465 2466 2467 2468 / TR 1 / 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 …omissis… 2460 2461 2462 2463 2464 2465 2466 2467 2468 / TR 2 / 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 …omissis… 2460 2461 2462 2463 2464 2465 2466 2467 2468 / TR 3 N.B.:THIS IS ONLY ONE OF THE METHOD TO CARRY OUT THE PHASE ANALYSIS: OTHER WAYS ARE TO CHANGE PROPERTIES OF THE INTERFACE MATERIALS, MODIFIED APPLIED LOADS, CHANGE OR DELETE THE INTERFACE ELEMENTS

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ANNEX C – Specifications of the works

Specification for the strengthening of the foundations

INDEX 1 - INTERVENTION

2 - MATERIALS TO BE APPLIED

3 - CHARACTERISTICS OF THE EQUIPMENTS AND TOOLS

4 - QUANTITIES TO BE MEASURED

5 – METHODOLOGY OF EXECUTION

5 - PROFESSIONAL QUALIFICATION

6 - SECURITY AND HEALTH

1) INTERVENTION The Contractor shall supply, install and test micropiles shown on the drawings or specified herein in

accordance with the specification

The Contractor shall allow for all necessary operations including scaffolding, handling equipment,

tools machinery etc necessary for expeditions handling of the work.

Setting Out: the Contractor shall be required to employ an approved licensed surveyor who will set up

the positions of the piles as shown in the pile layout plans of the detained design. The Contractor shall

be responsible for the accuracy of location and positioning of each pile.

Any errors in the setting out and any consequential loss to the Employer will be made good by the

Contractor to the satisfaction of the Engineer.

Tolerances. Position: the pile heads shall be positioned as shown on the Drawing within a maximum

deviation of 40 mm in either direction from correct centre point.

Verticality: the maximum permitted deviation of the finished pile from the vertical at any level is 1 in

150. The contractor shall demonstrate to the satisfaction of Engineer the pile vertically is within the

allowable tolerance.

Correction: should piles be installed outside these tolerances affecting the design and appearance of

structure, the Contractor shall propose and carry out immediate remedial measure to the approval of

the Engineer

Person in charge. The piling work is to be carried out by full time operators and supervisory staff who

must be experienced in the installation of the proposed type of piles.

The Contractor shall submit to the Engineer for approval, written evidence to show that the persons

who will be engaged in the works have had such experience.

The equipment and accessories must be capable of safely, speedily and efficiently installing piles.

Scope of work The contract comprises the provision of all labour, materials, tools, plant etc necessary for the

following work

a. Supply and installation of pile foundations to carry the loads as specified in the drawing

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b. Preparation for site earthwork, such as excavation and construction waste management

c. Cutting the piles to cut off levels specified and preparation of the pile head

d. Carrying out standards load test as specified

2) MATERIALS TO BE APPLIED

Steel pile: The type of steel pile, the diameter, grade, yield strength and stress shall be as specified or

as shown on the Drawing.

Grout: The grout mix design such as the water-cement ratio, the minimum grout strength at 7 and 28

days shall be specified and shown on the Drawings. Grout shall be tested in accordance with the

respective standard. Maximum bleed is limited to 5%. If the grout cube as tested failed to satisfy the

criteria as prescribed in Specification and drawings, the piles constructed using this batch of grout

shall be rejected.

Site and adjacent properties

Subsoil Data: the soil investigation report is included in the tender document only for information and

guidance, and shows the approximate nature of soil strata. The Engineer shall not be liable for the

accuracy of data given and the Contractor may carry out his own soil investigation to obtain additional

information.

Underground Services and Adjacent Property: the Contractor shall take care to ensure the safety of

underground services and adjacent properties during the installation of micropiles. The contractor will

be liable to any construction claims during piling operations.

3) CHARACTERISTICS OF THE EQUIPMENTS AND TOOLS

Diameter of Piles: the diameter of piles shall not be less than the specified diameter at any level

through its length.

Drilling: the Contractor shall submit to the Engineer details of drilling equipment and drilling procedure

before commencement of work.

Rock Coring: rock coring shall mean coring of sound bedrock. Coring of inclined rock surface, cavities

and boulder shall be considered as boring in soils. Rock socket length is specified according to the

respective Standard.

4) QUANTITIES TO BE MEASURED

- Micro-piling m (meter)

- Site Formation Earthwork m3 (cubic meter)

- Earthfilling m3 (cubic meter)

- Pavement m2 (square meter)

- Transport and instalation of the micro-Piling machine Global value

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5) METHODOLOGY OF EXECUTION

Grouting operations The Contractor shall provide details of the method and equipment used in grout mixing. Further

information such as grouting pressure, grouting procedure, grouting equipment and technique

employed in grouting shall also be submitted for approval.

Grout shall be mixed on Site and shall be free from segregation, clumping and bleeding. Grout shall

be pumped into its final position in one continuous operation as soon as possible and in case no more

than half an hour after mixing.

The Contractor shall decide to carry out the water tightness test to decide whether pregrouting is

required when difficult ground condition is encountered.

Standard load test Load test of 1.5 times the working loads shall be carried out on pile designated by the Engineers and

in accordance with the related standard. The number and location of test piles shall be to the

discretion of the Engineer. The Contractor shall submit a detailed proposal of the load test to the

Engineer and shall obtain his approval in writing before carrying them out. On completion of the test,

the Contractor shall submit to the engineer the results including graphs showing load and settlement

versus time and settlement versus load.

Test report The report shall contain the following

Pile designation, date completed, weather condition, pile length, pile size, volume of grout intake.

Description of the apparatus used for testing, loading system and procedures for measuring

settlement

Field data

Time/Settlement Curve

Load/Settlement Curve

Remarks explaining unusual events or data and movement of piles

Calibration certificates of dial gauges and pressure gauges

Damaged or displaced piles Should the deviation exceed the tolerance provided in this specification, the contractor shall submit

the remedial proposal for the approval for the Engineer. Failing this, the faulty pile shall be replaced by

additional piles as necessary in position as determined by the Engineering at no cost to the Employer.

The cost of modification shall be borne by the Contractor. The same will also apply to any piling work

rejected by the Engineer for not truly constructed and installed in accordance with the specification.

Where a pile has been damaged during installation, testing or by other causes, the damaged pile shall

be considered and treated as faulty pile and should be replaced by additional piles as approved by the

Engineer at the Contractor’s expense.

Piling record

Complete piling records shall be kept by the Contractor during pile installation. The Contractor shall

submit the following to the Engineer:

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Records of all piles at the work proceeds: Upon Completion, a record of the work as carried out and

as-built drawing. The record shall contain all information required by the Engineer which includes the

following where applicable:

reference number and position of pile

type and dimension

date of boring and nature of strata where each pile is bored

details of equipment used

ground level and base of excavation level

total penetration

length and position of cavity in each pile

penetration in rock

details of jointing operations, locations of sleeves

details of grouting operation

weather

top level of pile immediately after completion

errors in position and inclination

amount of grout the pressure used

size and position of boulder in each pile

6) PROFESSIONAL QUALIFICATIONS

This work will be executed by people with the necessary aptitude, acquired across of the experience

in work or appropriate education. The Inspector will be able to ask to the Contractor to present the

corresponding curricula and / or certificates of education, when applicable.

7) SECURITY AND HEALTH

All the works will have to be executed in accordance with the appropriate conditions of hygiene and

security, collective and individual, considering current legislation, namely in the concerning the use of

helmet, gloves, glasses, protection boots, ventilation and protection in scaffoldings and walkways.

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Specification for the application of tie rods







1) INTERVENTION

This activity includes all of the following works including the supply of all the materials, equipments

and tools that for such become necessary:

• supply and application of the scaffolding systems, if needed

• positioning and installation of the drilling system

• execution of φ 60 mm holes as specified in the drawings

• installation of the tie rods in pieces of equal length connected to each other by turnbuckles

• fill both ends of the hole

• positioning and installation of the anchorage system (stainless steel plates)

• the assembly, the maintenance and the dismantling of all the scaffoldings, walkways and

protections that become necessary


• Stainless steel tie rods φ 35mm type AISI 316 L

• Non retractable mortar type EPAM ANTIQUE


Tools for drilling holes

Dynamometric key (if needed)


- Length of tie rods and accessories m (meter)

- Crane global value

- Scaffolding m2 (square meter)

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- Injected Mortar kg (kilograms)

5) PROFESSIONAL QUALIFICATION








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Specification for the strengthening at the truss supports







1) INTERVENTION

This activity includes all of the following works including the supply of all the materials, equipments

and tools that for such become necessary:

• supply and application of the scaffolding systems, if needed

• positioning and installation of the drilling system

• execution of φ 30 mm holes as specified in the drawings

• underpinning the trusses (if needed)

• repointing of the cracks of the supports

• installation of the bars and the stainless steel beam (anchorage)

• fill the holes with epoxy resin

• the assembly, the maintenance and the dismantling of all the scaffoldings, walkways and

protections that become necessary.


• Stainless steel tie rods φ 35mm type AISI 316 L

• Non retractable epoxy resin


Tools for drilling holes

Tools for repointing


- Length of the bars and accessories m (meter)

- Injected epox resins kg (kilograms)

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- Length of the UPN 80 profiles m (meter)

- Mortar for repointing the cracks kg (kilograms)

5) PROFESSIONAL QUALIFICATION








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ANNEX D – Bill of Quantities

Bill of Quantities for the Monitoring system:

The proposed monitoring plan was sent to Centro Empresarial Tejo for a quotation.

Details of the rates quoted and the terms and condition proposed by the monitoring system is

presented in the following pages.

Centro Empresarial Tejo

Rua de Xabregas, 20 - Piso 2, Esc. 2.041900-440 Lisboa - PORTUGALTel. (+351) 218 683 559 - Fax (+351) 218 682 946e-mail: [email protected] - Internet: www.vortice-lda.pt

V/ Ref. Reunião Proposta Nº 14044Data: 2008-01-16 Data: 2008-03-05

Item Descrição Qtd Preço Unitário Preço Total

A Sensores

A.1 Linear Potentiometer, SLS130 - 25mm Stroke; 1K.Marca Soil Instruments, refª 604-109

6 384 € 2 304 €

A.1.1 Expanding Shell Anchor (2 no. required per radiocrackmeter).Marca Soil Instruments, refª J2CF-2.2

12 17 € 204 €

A.2 Vertical Cabled In-Place Uniaxial Inclinometer Sensor, ±5°range.Marca Soil Instruments, refª C12-1.1

2 432 € 864 €

A.2.1 Wall Mounting Bracket.Marca Soil Instruments, refª TLT2-1.5-5

2 43 € 86 €

A.3 Resistance Thermometer.Marca Soil Instruments, refª T2-1.10

5 100 € 500 €

A.4 Rotronic Temperature & Relative Humidity probe.Refª 633-068

1 822 € 822 €

A.4.1 Unaspirated Radiation Shield for CS215 probe, withmounting arm.Refª 633-086

1 179 € 179 €

B Estrutura base

B.1 Enclosure - Polyester/GRP.H530mm x W430mm x D200mm.Marca Soil Instruments, refª D1-2.7

1 432 € 432 €

B.2 Instrument Cable 4 core- Screened- 7/0.20 (per metre).Marca Soil Instruments, refª CA-3.1-4-IC

550 2 € 1 100 €

No seguimento da reunião realizada nas vossas instalações no passado dia 2008/01/16 e posteriores trocas deemails, nomeadamente o vosso email de 2008/02/15 com a definição de gamas de sensores, vimos por estemeio, submeter à vossa apreciação a nossa melhor proposta para uma solução técnica da marca SoilInstruments (Inglaterra).Ficamos entretanto à disposição de V. Exas para esclarecimento de qualquer questão que julguem necessário.

Banco BPI, S.A.

NIB 00 10 00 00 56 03 66 80 001-18 - IBAN PT50 0010 0000 5603 6680 0011 8Banco Millenium BCP

NIB 00 33 00 00 00 00 28 05 726-05 - IBAN PT50 0033 0000 0000 2805 7260 5

Instrumentos e Sistemas para:

Análise de Gás e de Partículas - Meteorologia - HidrometriaOceanografia - Monitorização da Qualidade das ÁguasFisiologia Vegetal - Geofísica - GeotecniaObservação de Estruturas - Aquisição de DadosRedes de Monitorização Ambiental

Exmos(as) Senhores(as)

Para:Universidade do Minho

Departamento Engenharia Civil

A/c Engº Luís RamosCampus de Azurém4800-058 Guimarães

Contribuinte nº VAT PT 501 144 552Capital Social 200.000,00 € Página 1 de 3

Sociedade por QuotasMatric. na C.R.C. de Lisboa sob o nº 1206




Item Descrição Qtd Preço Unitário Preço Total

B.3 Power Supply - Lead Acid Battery 115/220Vac.Marca Soil Instruments, refª D1-1.2

1 389 € 389 €

B.1 GSM Digital Transceiver (includes cable and antenna).Marca Soil Instruments, refª D1-3.5

1 648 € 648 €

C Aquisição dados

C.1 Campbell Scientific CR1000 - Datalogger module andwiring panel.Refª D1-1.1.2

1 2 255 € 2 255 €

C.1.1 16/32 Channel Relay Multiplexer - AM16/32.Refª D1-1.4

2 1 192 € 2 384 €

C.2 LoggerNet - Campbell Logger Operating Software.Refª D2-1.1

1 881 € 881 €

D Serviços

D.1 Configuration and Wiring for CR1000 (per logger).Includes customer specified logger program and fulltesting.

1 432 € 432 €

D.2 Configuration and Wiring for Data Logger System. 2 86 € 172 €

TOTAL 13 652 €

30 dias

30% Com a Encomenda 70% 30 dias da data da factura

Cerca de 4 SemanasLocal de Entrega:

ou outras a combinar com V.Ex.as Vossas instalações

Preços sem IVA ( acresce à taxa legal em vigor ) Validade da Proposta:

Condições de Pagamento: Prazo de Entrega:

Gestor de ProjectosEng.º Carlos Lopes Teixeira

Melhores Cumprimentos

Esta proposta está sujeita às condições gerais de fornecimento, constantes do documento anexo.






Exclusões - Todos os equipamentos / serviços não incluídos na proposta.

Os equipamentos propostos têm a garantia de 12 (doze) meses contra defeitos de fabrico. A garantia cobrepeças não consideradas consumíveis e mão-de-obra, para equipamento colocado nas nossas instalações. Agarantia não cobre deteriorações ou avarias devidas a transporte, desgaste normal, forças da natureza,utilização ou condições de operação indevidas, acções de terceiros ou intervenções técnicas intempestivas. Nocaso de intervenção local nos equipamentos em garantia, apenas serão debitadas as despesas de deslocação,tempo de viagem e estadia (quando se aplique). Salvo indicação em contrário, o prazo e condições de garantiaentram em vigor a partir da data da entrega do equipamento.

A Vórtice prestará por si, ou por entidades que para o efeito designará, a assistência técnica a todos osequipamentos fornecidos.

Os equipamentos serão entregues com os manuais de operação e instalação (quando se aplique), fornecidospelo fabricante.

O equipamento proposto poderá não corresponder, na íntegra, às vossas necessidades. Deveráconsequentemente ser verificada a sua adequação aos objectivos a atingir.

Condições Gerais de FornecimentoA venda é feita sobre reserva de propriedade; a falta de pagamento de uma prestação que exceda 1/8 dopreço total, ou a falta de pagamento de duas ou mais prestações, confere a esta Empresa o direito de rescindiro contrato, fazer suas as quantias já pagas e exigir indemnização por todos os prejuízos sofridos.

Só serão aceites as penalidades que por nós forem especificamente confirmadas por escrito.

Caso não haja nada estabelecido em contrário, só serão consideradas reclamações de quantidades,deterioração em transporte etc., no prazo de 8 dias a contar da data da Guia de Transporte.



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Item Description Unit Quantity Price per unit Global Price

1 Assembling and disassembling of the scaffolding G.V. --- 5,000 € 5,000.00 €

2 Monitoring system G.V. --- 13,652 € 13,652.00 €

3 Micro-Piling --- --- --- ---3.1 Site Formation Earthwork m3 600.0 5 € 3,000.00 €3.2 Earthfilling m3 570.0 6 € 3,420.00 €3.3 Pavement m2 30.0 75 € 2,250.00 €

3.4 Transport and instalation of the micro-Piling machine G.V. --- 5,000 € 5,000.00 €

3.5 Micro-Piling m 621.0 100 € 62,100.00 €

4 Outside Crane G.V. ---- 10,000 € 10,000.00 €

5 Stainless steel AISI 316 L, Incidental expensive, welding, turnebuckle, bolts kg 989.5 12 € 11,874.15 €

6 Supply and executions of the anchorage system --- --- --- ---6.1 Positioning and installing of the drilling system Unit. 12.0 70 € 840.00 €

6.2 Execution of the holes with φ 60mm for the anchorage m 16.8 300 € 5,040.00 €

6.3Placing the head of anchorages, including implementation of post-tensioning with dynamometric key

Unit. 8.0 70 € 560.00 €

6.4Injection of not retractable mortar type EPAM ANTIQUE at low pressure (up 0.1 MPa) in anchoring systems

kg 5.0 3 € 15.00 €

6.5 Painting the head of anchors G.V. --- 200 € 300.00 €

7 Strengthening of the truss supports --- --- --- ---7.1 Positioning and installing of the drilling system Unit. 12.0 50 € 600.00 €

7.2 Execution of the holes with φ 30mm for the anchorage m 8.4 200 € 1,680.00 €

7.3 Injection of not retractable epoxy resin in anchoring systems kg 10.0 3 € 30.00 €

TOTAL 125,361.15 €

VALOR TOTAL 125,361.15 €

BILL OF QUANTITIES

ANNEX E – Drawings

Title: Author(s): Nicola Merluzzi, Huiyin Lee, Kuili Suganya, Iat … · 2020-05-29 · Author(s): Nicola Merluzzi, Huiyin Lee, Kuili Suganya, Iat Meng Wan Unit: SA7 Institution:

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