Using HDS to Assess the Effects of the Haiti Earthquake on Various Types of Structures

Using HDS to Assess the Effects of the Haiti Earthquake on Various Types of Structures

Shakhzod Takhirov and Khalid Mosalam Shakhzod Takhirov and Khalid Mosalam

nees@berkeley and PEERnees@berkeley and PEER

University of California, BerkeleyUniversity of California, Berkeley

2010 Leica Geosystems Worldwide HDS User Conference, October 25-27, San Ramon, CA

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High-Definition Leica Laser Scanners

Scan Station 21 unit was acquired in 2008Single-point range accuracy of ±4mmAngular accuracies of ± 60 micro-radiansLaser beam spot size of 4mm from 0-50m rangeField of view: 360° x 270°.Built-in camera for taking snap shots of the object and specifying scan zonesCyclone software application


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Background: Wood-Frame Building Evaluation after Earthquake

Wood-Frame Building Test: Before and After Scans4-5 scans in each conditionsAt least 4 reference targets for each scanBest resolution: 1000x1000 points Scans stitched together based on the reference targets


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Wood-Frame Building Test: Before and After ScansContour of deformed shape of the north wall


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Before and After ScansCompare vertical slices of building before and afterHDS point cloud well correlates to transducer data


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Before and After ScansCompare horizontal slices of building before and afterHDS point cloud well correlates with transducer data


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Background: Long Range Leica vs. Short Range Konica Minolta

Several individual scans from all sides of a specimen were obtainedStitched together in application supplied by the scanner manufacturer (Cyclone and Polygon)3D image of the specimen is generated

Model Manufacturer Range, m

Accuracy, mm

Target acquisitio

n accuracy,

mm

Achieved stitching accuracy (error)

Scan Station 2

Leica Geosystems

100 4 <1 < 4 mm

Vivid 910 Konica Minolta 1.2 0.22 NA < 0.4 mm


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Longitudinal slices:Scan Station 2 (slice thickness 4 mm: scan range ~ 10 m)Vivid 910 (slice thickness 1 mm: scan range < 1m)


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Transverse section:Scan Station 2 (slice thickness 4 mm: scan range ~ 10 m)Vivid 910 (slice thickness 1 mm: scan range < 1m)


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Points cloud from Vivid 910 scanner:Transverse sections with position transducer readingsLongitudinal sections with position transducer readings


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Structural Damage Assessment in Haiti

More than 20 structures were scannedFor each scan position a panorama was generated


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Environmental conditions on the sites

Structure Time of scanPeak temperature

shadow (direct sun), FDate

Residential building

PM scans NA 6/29/2010

Asscotia Hotel AM scans 104 6/30/2010

Mon Parfum PM scans 100 6/30/2010

Bank Building AM scans 106 7/1/2010

Hospital PM scans 105 7/1/2010

Block 7 AM scans 117 (136) 7/2/2010

Church PM scans 102 7/2/2010

Bridge AM scans NA 7/3/2010


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Bridge damaged during the earthquake was scanned from 2 positions


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3D panoramic view of the bridge from Station 2.


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The cross sections of the shear key (images #1 and 2) at it face is shown in image #3. The section taken at the middle of the shear key is shown in image 4 with zoomed view shown in image 5.

9.2 mm

1 2 3 4

5


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Registration of Asscotia Hotel and nearby intersection

N


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Two horizontal sections at the 1st story of Asscotia Hotel are reduced in Matlab and overlaid on top of the building image in Google Earth


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Clicking on balloon with Cal sign will bring interactive panoramic movie of the building and its surrounding (user can look around the shooting point and zoom into certain details)


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Clicking on balloon with Cal sign will bring interactive image that contains links to points clouds generated by the laser scanner (TruView), so measurements of the objects can be performed


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Points with colors based on deviation of columns from a vertical plane show residual deformation of south wall of Asscotia Hotel


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Residual drift and directivity is estimated from the difference of the top and bottom slices

7.4 7.5 7.6 7.7 7.8 7.9 8 8.1 8.2-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

East-West Coordinate (m)

Nor

th-S

outh

Coo

rdin

ate

(m)

Scans of Bottom and Top Portions of First-Story Columns (1 m Apart)

2.3%

Bottom Slice

Top Slice

-0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6

1.5

2

2.5

3

3.5


Nor

th-S

outh

Coo

rdin

ate

(m)


3.4%

Bottom Slice

Top Slice


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Two horizontal sections at the 1st story of Asscotia Hotel were reduced in Matlab and overlaid on top of the building image in Google Earth showing calculated residual drifts in

the columns


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Structural Damage Assessment in Haiti: Validation

Corner beam-column specimen for a study on non-ductile RC frames


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Structural Damage Assessment in Haiti: Validation

Validation of the technique in the lab conditions: digital level readings were 10.82% (top) and 11.82% (bottom)


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Block 7 from Google Earth imagery taken on January 25, 2010


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In opposite to conventional ground surveillance laser scans quantify the degree of permanent damage and its directivity

1st building at south-east corner

Ground observations presented by Eduardo Fierro


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In opposite to conventional ground surveillance laser scans quantify the degree of permanent damage and its directivity

2nd building at south-east corner

-21 -20 -19 -18 -17 -16 -15 -14 -13 -12 -11-2

-1

0

1

2

3

4

5

6

7

8

0.8%

1.8%


Nor

th-S

outh

Coo

rdin

ate

(m)


Bottom Slice

Top Slice

Ground observations presented by Eduardo Fierro


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Overall residual drift and directivity is estimated from the difference of the top and bottom slices for Asscotia Hotel

Rotation [radians]

X-translation

[mm]

Y-Translation

[mm]

Drift translation vector [%]

Drift angle to X

[degrees]0.0013 -14.4 -27.5 3.1 207.60

Thank you!

The authors acknowledge the financial support, Award # 1034808, from the National Science Foundation through the RAPID Program. Thanks are due to Mr. E. Fierro and Prof. E. Miranda for being members of the reconnaissance team. The following PEER/nees@berkeley summer interns: Victoria Servin, Clay Sorensen, and Sean Wade, contributed to the pre- and post-field work using the laser scanners. Their help is gratefully acknowledged.

http://nees.berkeley.edu

Using HDS to Assess the Effects of the Haiti Earthquake on Various Types of Structures

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