Measuring techniques of building façades Rak-43.3312 Repair Methods of Structures II (4 cr) Esko Sistonen.

Measuring techniques of building façades

Rak-43.3312 Repair Methods of Structures II (4 cr)

Esko Sistonen

Information is needed:

the surface area of the façade to berepaired

-the whole façade dimensions, the original drawings (inaccurate or missing)

Information about the facade dimensional tolerances, especially important in the repair of the old facade in which it is covered with a cartridge or shell element solution

 Tachymeter+ GPS

Laser Distance Meter

DVP-photogrammetric method (stereo pairs of images)

The Use of ICT 3D Measuring Techniques for Visual Inspection

of Building Facades

KITARA- Rakentamisen laadun parantaminen 3D-mittaustekniikan avulla

– Background• Building envelope• Deterioration of building facades • Visual inspection• Similar laser-scanning research (different fields)

– Research focus– Methodology– Some expected results

Objective

• to develop ICT-based tools to automatically retrieve dimensions of factory-made elements and their surface quality as well as deformations after installation and automatic comparison of these variables against 3D CAD models

The work consists of the following tasks:1. To develop methods for analytic and visual inspection of deviations

between planned and measured dimensions of component units.2. To develop methods for verification of the skeletal structure of a

building and surface quality of the facade.3. To identify measuring devices and establish the tolerances for the

new up-to-date component technology and to study the propagation of precision through the whole measurement process, considering both instrumental properties and measurement geometry.

4. To improve the measuring process at the construction site.5. To study the potential of terrestrial laser scanner in construction

monitoring.6. To develope image based methods to extract geometric information

from buildings and to create methods to produce image data suitable for CAD-overlaying.

Research focus

• The research will focus on the building envelope facades, windows and outer doors.

• Brick and concrete wall façades will be investigated.

• The research doesn’t involve glass or steel facades (future work?).

Research procedure

• Selecting of building facades (concrete and bricks facades)

• Field work (Laser scanning and tacheometry as reference)

• Image processing (Scanning software)• Model creation (AutoCAD)• Database design (include modeling data + photos?)• Develop condition surveying methods (feature

extraction and inspection of the model)

Building envelope

Deterioration of building facades

Spalling of concrete cover due to corrosion

Frost damage

Cracking of concrete panels

Bending of concrete panels due to frost action

• Deformations and bending of concrete elements • Delamination of bricks and rendering coatings • Windows and doors cracks and paints etc (?)• Reconstitution (interpretation) of building facades and

balconies (comparing to original drawings)

Visual inspection of building facades

Literature reviewRoad surface texture inspection using high resolutionTransverse profile measurementsC. MAYS et al 2006,Phoenix Scientific Inc.

Literature reviewFeature Extraction And Modeling Of Urban Building From Vehicle-Borne Laser Scanning Data B.J. Li, 2004 Hong Kong, China

DoPP = Density of Projected points

Literature review Deformation Measurement using Terrestrial Laser Scanningat the Hydropower Station of GabčíkovoThomas SCHÄFER, 2004Slovakia

Selecting building facades

Selecting building facadesRaiviosuonmäki 7, Vantaa. Kohteessa on kaksi rakennusta 5- ja 4-kerrosta

FARO LS 880 laser scanner. www.faro.com

Scanning

The tacheometer Leica TCA2003

Potential research idea

Before earthquake After earthquake

• Current methods for evaluating earthquake damage for load bearing structures are visual

• Laser scanning is a potential measurement method for forming a database of load bearing structures of important buildings, like airports, train stations, governmental buildings etc.

• Quick scanning of damage after earthquake secure the safety of buildings & people

Results Examples from the literature review

Results

Examples from the literature review (quality control in the metal industry using laser scanning)

Detecting the Deterioration of Building Facades Using Terrestrial Laser Scanning Technique

• Field measurements (TLS & Tachymeter)• Bowing of marble cladding building facades • Crack in the building facade footing• The surface structure of the marble panel

Bowing Potential Test

Bow-meter

Field measurements (LTS & Tachymeter)

Anna Erving

KITARA- Rakentamisen laadun parantaminen 3D-mittaustekniikan avulla 20.3.2007

Building Quality

KITARA- Rakentamisen laadun parantaminen 3D-mittaustekniikan avulla

Building Quality

KITARA- Rakentamisen laadun parantaminen 3D-mittaustekniikan avulla

Building Quality

KITARA- Rakentamisen laadun parantaminen 3D-mittaustekniikan avulla

Building Quality

Antero Kukko

Crack in the building facade footing

KITARA- Rakentamisen laadun parantaminen 3D-mittaustekniikan avulla

Nina Heiska

The surface structure of the marble panel

Antero Kukko

Conclusions

• Laser scanning is a new technology for acquiring building facade data in three dimensions with high accuracy and low processing time.

• The rapid collection of 3D information serves several purposes including historical documentation, building condition documentation, construction as-built development, and BIM development.

• The result will be:– Methods to automatically extract geometric information from laser scanner

data– CAD-tools for analytical and visual monitoring of the building condition

• laser scanner instrumental and methodological errors!!

Conclusions

3D laser scanning has become an emergingly prominent vehicle for acquiring building spatial data in three dimensions with high fidelity and low processing time. The rapid collection of 3D information serves several purposes across GSA business lines, including historical documentation, facility condition documentation, construction as-built development, and BIM development.

The potential of terrestrial laser scanning for detecting the

deterioration of building facades

Concrete Solutions 20093rd International Conference on Concrete RepairVenice/Padova, Italy29 June-2 July 2009.

Outline of the presentation

o Introduction• Research project

• Laser scanning

• Building facades inspection

o Field measurements

o Results

o Conclusions

o Future work

Page 36

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

Research projecto This paper is a part of the research project:

“Use of ICT 3D measuring techniques for high quality construction” o Research group:

• Structural Engineering and Building Technology, TKK:

Fahim Al-Neshawy; Susanna Peltola; Jukka Piironen and Prof. Jari Puttonen

• Institute of Photogrammetry and Remote Sensing, TKK:

Anna Erving; Nina Heiska; Pano Salo and Milka Nuikka

• Finnish Geodetic Institute:

Antero Kukko

Page 37

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

How laser scanning works

Page 38

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

o Laser scanners use either the Time-of-Flight (TOF) measurement method or phase-based measurement to obtain target point distance.

o Time-of-Flight measurement is based upon the principle of sending out a laser pulse and observing the time taken for the pulse to reflect from an object and return to the instrument.

o Advanced high-speed electronics are used to measure the small time difference and compute the distance range to the target.

o The distance range is combined with high resolution angular encoder measurements to provide the three-dimensional (X,Y,Z) location of a point.

o Laser scanner is capable of measuring up to 50,000 distances per second.

Laser scanning data processing

Page 39

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

Raw XYZformatting and exporting the raw data into

raw XYZ data from the scanning system

Raw XYZformatting and exporting the raw data into

raw XYZ data from the scanning system

Aligned XYZdetermined by processing third-party

software

Aligned XYZdetermined by processing third-party

software

Processed modelis the basis for the interpretation and

decision making

Processed modelis the basis for the interpretation and

decision making

Raw observationscollected by the scanner

Raw observationscollected by the scanner

Laser scanning for building facades inspection

Page 40

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

Examples:• Deformations and bending of concrete elements • Delamination of bricks and rendering coatings • Reconstruction of building facades drawings

(comparing to original drawings)

Field measurements

Page 41

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

FARO LS 880HE80 terrestrial laser

scanning system

Leica TCA2003 tachymeter

Measurement distance to the façade• 4.5 m to the center of the facade• About 5 m to the corners

Sketch of the bow-meter and the location of the measuring points on the marble panel.

Bowing of marble panels

Page 42

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

Terrestrial laser scanning data, colored by the magnitude of the deformation in meters from the planarity.

Bowing of marble panels

Page 43

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

• The bowing of marble panels was calculated according the following formula:

where

B is the bowing magnitude (mm/m) d is the measured value of bowing (mmL is the measuring distance between the supports of the marble panel in (mm).

• The bowing of the convex and concave marble panels was calculated by fitting a second order curve to the laser scanning point cloud data from the centre line of the panel both in the vertical and the horizontal direction.

1000L

d B

Bowing of marble panels: examples

Page 44

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

Bowing of marble panels

Page 45

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

Method Marble panel Type of bowing B(mm/m)

Laser scanning

Mar–R4–C2 (Hal) Convex 6Mar–R4–C2 (Val) Convex 9Mar–R4–C4 (Hal) Concave -6Mar–R4–C4 (Val) Concave -9

Tachymeter

Mar–R4–C2 (Hal) Convex 8Mar–R4–C2 (Val) Convex 8Mar–R4–C4 (Hal) Concave -9Mar–R4–C4 (Val) Concave -10

Manual measurement (Bow-meter)

Mar–R4–C2 (Hal) Convex 5Mar–R4–C2 (Val) Convex 7Mar–R4–C4 (Hal) Concave -6Mar–R4–C4 (Val) Concave -7

Results of measurements carried out on the marble facade using terrestrial laser scanning system tachymeter and bow-meter

Surface delamination of bricks

Page 46

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

Aligned XYZGeoMagic studio

software

Surface delamination of bricks

Page 47

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

• Example of the delamination of bricks and the deterioration of joints detected from the laser scanning data.

• The maximum delamination of the bricks (red colour) was about 10 mm from the outer surface.

• The depth of the weathered plaster of the joint is about 10 mm.

Reconstruction of building facades drawings

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Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

Conclusionso Laser scanning is not a replacement for existing condition survey

techniques, but an alternative , which provides location based information on the building defects and deterioration

o Terrestrial laser scanning technique gives a reasonable method for measuring the bowing of marble and many other kinds of cladding panels

o The extracting of the deterioration features of building facades like surface delamination of bricks and joint failures can be performed from the laser scanning data

o Due to large amount of three dimensional data, efficient computing and analysis tools are needed to be developed and tested

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Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

Future work: 4D concept

Page 50

Introduction Introduction

Field measurements

Field measurements

ResultsResults

ConclusionsConclusions

Future workFuture work

Measurement technology (Real world)

Laser scanning

Photogrammetry

Visual inspection

Automatic evaluation of

the condition of the structure

Condition surveydatabase

Analysis

Time (years)