Malaga

Presentation to ERES 2001Malaga, Spain

September 2001Dipl.-Ing. Maria Bostenaru

4-6.09.2001 ERES 2001 Malaga, Spain

Calculation of Costs for Seismic Rehabilitation of Historical BuildingsMaria Bostenaru, University of Karlsruhe, GERMANY

Structure

• Introduction• Requirements on this methodology• General methods for costs planing• Special conditions for retrofitting existing buildings• Costs calculation methodology• Conclusions



Introduction

• Disaster prevention has growing importance• retrofit measures

– structural aspects– functional aspects– aesthetic aspects– economic efficiency

• building retrofit | building rehabilitation• information on the building ist required• methods on costs estimation available only in some

countries



Requirements on this methodology

• should not require location specific values (major goal)• flexible

– applicable in different regions– adaptable to different requirements process– extensible according to the growth of knowledge in this field

• computer based– extensible to net



General methods of costs planing

• Planing the costs– a method– an adequate structuring of the building object– scheduling of the structural elements and their quantity– documentation of the results– analysis– optimising alternative

• range influenced by data availability and not from target precision

• strong relation between data collected and costs estimation methods in a particular country (FEMA, BKI)



General methods of costs planing

• New buildings• Existing buildings



New buildings

• 2 main German indexes– costs estimation

• building divided into spaces with different functions• key area types• database with similar buildings• applicable in incipient stages of planning

– costs calculation• building elements are classified after their execution type• different deepness levels in the structure• applicable in later stages of planning



Existing buildings

• costs evaluation methods for upgrading existing buildings only developed beginning with the last decade

• systems used by calculation methodologies:– space usage– building surfaces– building elements– execution steps

• methodology of Rolf Neddermann: „old building types“– ready-made service packs during the planning within the

element methodology



Special conditions for retrofitting existing buildings

• Performance level• Decision support• Types of buildings

– Inter-bellum Bucharest buildings– Retrofit consideration about historical buildings



Performance level

• Objectives– immediate occupancy– damage control– life safety

upgrading existing buildings seismic retrofitrehabilitation expensedegree

performance objectives

damage degree present danger degree



Decision support

• local measures– similar to usual renewal of old buildings

• global measures– new elements have to be build in

• this methodology creates a framework, in which further values, coming from static calculations can be introduced



Decision support between local and global measures

allowedstrain

existingstrain

first measures level:repairing

second measures level:isolated elements retrofit

third measures level:whole building retrofit



Types of buildings

• historical buildings in town analysis– cultural value

• belong to national heritage• no statistical approaches possible

– architectural value• representative for a certain building style• retrofit methods restricted through the characteristics of that style

– environmental value• with positive influence on the townscape• the building record is the basis for town image analysis



Inter-bellum Bucharest buildings(1920-45)

• mainly residential buildings– 7-11 floors high apartment blocks

• RC frame structure with URM masonry infill– designed to resist vertical loads only

• non contextual architectural approach– set landmarks in the build context

• stylistically very close to turn-of-century European styles– lack of ornaments– aesthetics through simplicity– emphasis of horizontal lines– recesses in the facade



Costs calculation method

Marcel Iancu building (about 1935), 3 Pictor St. Luchian Street

Street front with an inter-bellum building



Retrofit considerations about historical buildings

• this methodology breaks up with the statistics– customised approach of different kinds of buildings allowed

• guidelines about the characteristics to be maintained• catalogue of adequate building elements

• consulting an architect still needed



Costs calculation methodology

• The building record• Retrofit elements• Spatial relationship• Database



The building record

• different detailing ranges• focus on the elements on the last division level• focus on the structural elements

– damages– bearing/non bearing parts

• RVS to identify where to search after structural details• the record methodology must allow computer assistance

but be easy to make with low-end equipment• the data have to be stored in a room book

– static measures have to be divided accordingly



Retrofit elements

• The result of retrofit measures are building elements• further division levels

– walls in their bearing and non bearing parts– bearing parts into linear, surface and node elements

• a retrofit element consists of all works which have to be done in order to strengthen, repair, build a constructive component– old elements (strengthened ones)– new elements (added to the build substance)– retrofitted elements (old elements with new extensions)– replaced elements (new elements instead of deteriorated old

ones)



Retrofit elements and retrofitted elements

columns beams

concreteextention

slotreinforcement

diagonale braces

stiffening

structural connected parts

steel masonry concrete

manteling

columns

parts included inother assemblies

single parts

structural parts openings

"line" elements



Gebäudestruktur II

interior wall exterior wall

bracing

partial

manteling

complet

frame field

frame construction

units of the structural parts

partial

interior wall

webbing

plates concrete

manteling

facade

manteling

partition wall(between buildings)

exterior wall

total

bearing walls floors

"surface" elements (also parts)



Retrofit elements

• required– clear identification of the building elements– marking of the elements in the 3D model

• building elements can be edited as service specification– Tendering-Allocation-Billing modules

• elements consist of service specification positions given in a database

• element costs are not statistically calculated• element costs are leaded back to the execution steps

which caused them



Surface elements

• posterior mounting of slabs in reinforced concrete frames– 5700 - 6700 DM/frame– 2000 - 2350 DM/m3concrete

1

3

4

2

5

1

6

6

21. vorhandene Stütze, 2. vorhandenes Fundament, 3. nachträglich eingebaute Scheibe,4. nachträgliche Fundamentergänzung,5. Bewehrung, 6. nachrägliche Querschnittserweiterung

F

• Posterior mounting of diagonals in reinforced concrete frames– 6800 - 7300 DM/frame

V- oder K- Anordnung X- Anordnung



Retrofit Elements

• Diminution of the rigidity– 100 DM/field

Kautschuk 1

1 1

1 8

2

7

5

3

6

4

9

10

1. alter Beton, 2. beschädigter alter Beton, 3. neuer Beton, 4. ausgeknickte Bewehrung, 5. neue Bewehrung, 6. neue Bügel,7. Schweißnaht, 8. alte Bügel, 9. alte Bewehrung, 10. Schalung

• Retrofit of a column



Example

4

3

1

: Mauerwerk

: Stahlbeton2

4,00m

3,00m2,88m

5,00m

Scaffolding area 4*6*3,00*5,00= 360m²

Masonry to be broken away 4*6*4,00*2,88*0,36= 99,54m³

Masonry to be cleaned up 4*6*4,00*2,88*0,36= 99,54m³

concrete (d= 25cm) 4*6*2,88*4,00*0,25= 69,12m³

Steel (reinforcement: ca. 120kg/m³) 120*69,12= 8294,40kg

formwork 2*4*6*4,00*2,88= 553,00m²



Example

Scaffolding area 4*6*3,00*5,00=360m²

Masonry to be brokenaway

4*6*4,00*2,88*0,36=99,54m³

Masonry to be cleaned up 4*6*4,00*2,88*0,36=99,54m³

concrete (d= 25cm) 4*6*2,88*4,00*0,25=69,12m³

Steel (reinforcement: ca.120kg/m³)

120*69,12=8294,40kg

formwork 2*4*6*4,00*2,88=553,00m²

Material Costs

concrete 200,00*69,12= 13824,00DM

steel 8294,40*1,00= 8294,40DM

anchorelements 5,65*60*4*6= 8136,00DM

sum 30254,40DM

process costs

1.put up the scaffolding 16,00*360,00=5760,00DM

2. screening 72,00*2*4=576,00DM

3. put up and away the wastetub

72,00*4*4=1152,00DM

4. break away masonry wall 72,00*5,60*99,54=40134,53DM

5. floor break through 4*6*2*175,00=8400,00DM

6.clean up of masonry brokenaway

(25,00+11,50)* 99,54m³=3633,21DM

7. reinforce – anchoring of thereinforcement into existingreinforced concrete frames

(72,00/60*8294,40)=9953,28DM

(4*6*72,00*10)=17280,00DM

9953,28+17280,00=27233,28DM

8. casing 4*6*72,00*3=5184,00DM

9. paving over 4*6*72,00*1,5=2592,00DM

10. casing away 4*6*72,00*2=5184,00DM

99849,02DM



Spatial relationship

• Building divided in– points (nodes)– lines (beams and columns)– areas (Floors and walls)

• executed works are related to this elements• static programs can communicate with this elements• the elements will be assigned in a GI-System using the

concepts of edge, surface and node



Database

measures book

spatialmodel(GIS)

static

room book

building elements

service directory

1

1

1 1

nn

n

n



Conclusion

• The method wasn't‘t applied until now– no statements about certainty degree

• a service directory can be hold out from the same database

• modular structure– allows generalisation– values can be stored in a standardised format in order to build a

database of retrofitted objects• costs estimation for similar future projects

Malaga

Technology

spain calculation of

germany new buildings

university of karlsruhe

similar buildings applicable

costs estimation methods

bellum bucharest buildings

building retrofit

costs estimation available