Bridge Damage Assessment

Transcription

1 Remote Sensing for Post-disaster Bridge Damage Assessment Beverley J. Adams Ph.D. Charles K. Huyck Sungbin Cho Ronald T. Eguchi

2 Outline The Idea Damage Detection Algorithms Bridge Hunter Bridge Doctor Results for Northridge Damage Profiles Scatterplots Application to Salt Lake City SAR simulation The way forward

3 The Idea Remote sensing technologies will facilitate rapid and comprehensive assessment of postdisaster damage Application to a broad range of hazards: Earthquake, flooding, landslide Terrorist attacks Benefits: Saving lives Aiding emergency response Reducing overall losses

4 Damage that will look like this.. Hwy I5 118 MISSION GAVIN CANYON GOTHIC

5 Damage Detection Algorithms Tracks Diagnoses down bridges the health of interest of bridges in after Bridge remote Hunter sensing Doctor an earthquake or terrorist imagery attack

6 Bridge Hunter Database JOIN Dynamic Segmentation GIS Database JOIN

7 Bridge Doctor 1. BEGIN WITH BEFORE & AFTER IMAGES OF BRIDGE 2. CHANGE DETECTION COMPARE BEFORE & AFTER IMAGES 3. QUANTIFY DAMAGE COMPARE & INTERPRET CHANGE IMAGES Subtraction Correlation Damage profile Scatterplots Before [b 1 ] After [a 1 ] Bridge damage Change [b 1 a 1 ] Change Correlation Distance Difference

8 Sample of Bridges Collapsed No-damage

9 Change Detection I5 Gavin Canyon Mask Transect Bridge Non-bridge bridge

10 Difference USGS Air Photo SPOT PAN data

11 No Damage Profile SR101/Tampa DN value After Before Highway Bridge Highway Distance from start of transect (m) Before - After (DN value) Highway Difference Bridge Highway Distance from start of transect (m)

12 Collapsed Damage Profile I5 Gavin Canyon DN value Highway Bridge Highway Highway Bridge Highway After Before Before - After (DN value) Difference Distance from start of transect (m) Distance from start of transect (m)

13 Correlation I5 Gavin Canyon <

14 Damage Plot 40 Difference in Intensity, Average Value per Bridge Correlation Between Images Calculated in a Dynamic 5 by 5 Pixel Window, Average Value per Bridge -0.4 No damage Collapsed

15 Initial Findings Bridges and highways are readily distinguished on SPOT panchromatic data Damage profiles and bi-variate scatterplots are useful tools for damage assessment The Bridge Hunter / Bridge Doctor methodology successfully distinguishes between collapsed and non-damaged structures

16 Application to Salt Lake City C617 (a) No filter Highway Bridge Highway Highway (b) 7.5m filter Bridge Highway DN Value Time 2 Time DN Value Time 2 Time Distance from start of transect (m) Distance from start of transect (m)

17 Damage States FULL COLLAPSE FALLEN SPAN PARTIALLY FALLEN SPAN TILTED SPAN ELEVATION VIEW PLAN VIEW a c c

18 SAR simulation Plan Elevation

19 Output from X-patchX Before X-patch Specifications * Freq. = X band * Polarization = VV * Resolution = 1m * Flight path = parallel to bridge After No damage Fallen span Image Bin Number Unit in db Image Bin Number Unit in db Image Bin Number Image Bin Number

20 Operational End to End Solution Real-time monitoring Bridge Hunter & Bridge Doctor enable rapid damage detection Network Flow Modeling: REDARS Emergency response DETOUR AHEAD Network Attack modeling $$ 10 Redars/GH

21 Emergency Response Routing emergency vehicles E Detour routing Loss estimation for Presidential declaration Construction awards S Optimal route Post-earthquake Pre-earthquake

22 Remote Sensing for Post-Disaster Bridge Damage Assessment Contact: Dr. Beverley Adams