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7/10/2018
1
Earthquake and Structural Damage Reconnaissance with Advanced Tools
Andre R. Barbosa, Ph.D.
Associate Professor, Oregon State University
Overview• What’s unique? Why is a Rapid needed…
• The Extreme Event• Research Questions• The Team / “The Fixer”• Contact NSF…
• Trip Planning• Team Logistics• Equipment, tools, Software, Data Collection Procedures• Health and Safety, Risks• Contact NSF…
• Example Data• Data Collection• Reports and Published Data:
• Other potential applications• Other hazards: recon• Large‐scale testing
https://doi.org/10.17603/ds2p082
7/10/2018
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The Extreme Event: 2015 Gorkha Earthquake
EpicenterMay 12
EpicenterApril 25
Mt. Everest
Kathmandu
Mainshock on April 25, 2015 with magnitude 7.8
Shallow earthquake, with a focal depth of 8.2 km
Epicenter was in Lamjung, Gorkha district, 75 km northwest of Kathmandu
Mainshock followed by 400 aftershocks of 4.0 Mw, including a 7.3 Mw east of Kathmandu (May 12)
Measured peak ground accelerations (PGA)
in the E‐W: ~ 0.26g; in the N‐S ~ 0.16g
Caused more than 9,000 fatalities, almost 25,000 injuries and damaged beyond repair over 500,000 buildings
Most of the damage was on poorly engineered unreinforced masonry buildings.
Approximately 25 per cent of the building stock consisted of reinforced concrete (RC) frames infilled with masonry walls.
30 Miles
Research Questions
1. Post‐earthquake assessment of existing RC building frames with masonry infill. Thisstructural system was widely used in the 1920s and 1930s in California as well as inthe Pacific Northwest; hence, understanding the damage to this structural systemfrom the Nepal earthquake has direct implications for the seismic performance of alarge number of buildings in metropolitan areas in the United States.
2. Quantitative damage measurements performed using 3D, ground‐based lidar (GBL)scans, UAS Structure fromMotion (SfM).
NSF RAPID
Additional work / Initial WishlistA. Dynamic system identification of RC infilled buildings
a) Non‐engineered buildings (with and without damage)b) Well designed buildings (with and without damage)c) Identification of frequency of infill walls (with and without damage)
B. Damage assessment of urban/rural areas using visual damage assessments (rapid anddetailed)
C. Inform local agencies in Nepal on suggested rebuilding and recovery guidelines.
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The Team / The Fixer Oregon State Univ. : Andre Barbosa, Michael Olsen, Dr. Dan Gillins,
Rajendra Soti, Patrick Burns, Matt Gillins
U. Buffalo: Andreas Stavridis, Supratik Bose
NSET: Surya Shrestha, Ramesh Guragain, Dev Maharjan
PEER: Stephen Mahin, Grace Kang, Matthew Schoettler
U. Porto: Humberto Varum, Antonio Arede, Hugo Rodrigues,
Nelson Vila Pouca, Andre Furtado, Joao Oliveira
U. Chieti‐Pescara: Enrico Spacone, Giuseppe Brando, Davide Rapone
U. Roma‐Sapienza: Rosario Gigliotti, Marco Faggella
U. Nebraska: Richard Wood
Tufts U.: Babak Moaveni
Trip Planning
30 Miles
Epicenter12 May
Epicenter25 April
Mt. Everest
Nuwakot
Charikot
Barabise
Chautara
Kathmandu
Bhaktapur
Piskar
Manakamana
Towns and areas to be visitedAdditional towns and areas visited
• Information about the existing field situation• Main objectives/goals/focus for each group• Research opportunities to gather, analyze
and synthesize field data • Areas of interest • Pre‐departure checklists, authorizations, and
procedures o Examples: EERI, Masonry Society, GEERo Travel information: Health, Visa,
embassy letterso Liability release forms o Practical/sharable data collection and
uploading Google Drive? Others? Forms: ATC‐20, NSET, Others?
• Contact information about on‐site people as resources, as well as other earthquake recon teams
• Travel dates
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Trip Planning
• Travel information pre‐trip checklist, authorizations, and procedures o Logistics:
Base camp Equipment / Work room / Debrief room
Transportation of people, food, water, and equipment (Rentals, Drivers, Licenses, Safety) Payment methods (Cash only? Credit cards? Contingencies?)
o Equipment: List of Equipment, Special Needs, Authorizations, Carnet
o Travel information: Weather Food/water safety Disaster Preparedness Supplies Avoiding Illness Information about the existing field situation
o Health CDC (Center Disease and Control)o Check with your university Risk Consultant on
Risk management plan and travel insurance Risk mitigation plans, including training on: communication plan, knowing what to do in the
event of an earthquake, plans for shelter, develop plans to avoid food/water contamination, etc.
Trip Planning
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RC structures with infills
Three (3) tall buildings
Six (6) school buildings
Two (2) hospitals
25 residential buildings
Two (2) Historic Centers
Bungamati and Bhaktapur
Seven (7) Urban and Rural Areas
Kathmandu – Gongabu, Sitapaila
Sindhupalchowk – Chautara, Barabise, Charikot, Piskar
Ghorkha – Manakamana
Three (3) historical URM structures
Landslides and liquefaction
Full list available at: http://web.engr.oregonstate.edu/~barbosa/NEPAL/earthquake‐reconnaissance/list_of_assessed_structures.htm
Forms:
ATC‐20 Rapid Evaluations
ATC‐20 Detailed Evaluations
Non‐destructive Testing
Schmidt Hammer Testing
Rebar Scanner
Ultrasonic testing
Ground‐based Lidar (laser scanning)
Unmanned Aircraft Systems (UAS)
StructuresType of Assessment
Team Effort
GBL and Ambient‐vibration Testing at the Building Structure Scale
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18‐story RC Building, Katmandu
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18‐story Building: Cityscape #1
• 18‐story building, located in Kathmandu, Nepal.
• Extensive non‐structural and moderate structural damage.
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Observed damage• Mostly infill walls
• Some beam‐column joint cracks
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Data Collection• Ambient vibration using wired accelerometers
• LIDAR on the outside and inside of the structure
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Laptop
Portable DAQ
Accelerometer
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FE model vs System ID Correlation
• The first three natural frequencies are very closely spaced
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Frequency [Hz] Mode1 Mode2 Mode3
FE Model 0.64 0.72 0.85
System ID 0.61 0.67 0.73
FE model of Cityscape #1 building in SAP2000
Response Prediction
• Linear time history analysis for mainshock (M7.8) and aftershock (M7.3)
• Inter‐story drift ratios of the different stories
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Light Damage Moderate Damage
Sto
ry
Peak inter-story drift (%)
6th story
3rd story
9th story
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4‐story RC School Building, Shanku
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• 4‐story RC frame building with masonry infill walls
• Damaged during 2015 Gorkha EQ
• Visited by authors in 2015
• Collected post‐EQ ambient vibration and laser scan data
School Building, Sankhu
Sankhu
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Damage Quantification
FEM Modeling Results
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Frequencies (Hz)
System ID
Initial Model
Mode1 1.19 1.30
Mode2 2.16 2.69
Mode3 3.16 3.39
SystemID
InitialModel
DeterministicModel
Updating
BayesianModel
Updating
Frequencies(Hz)
Mode1 1.19 1.30 1.19 1.20
Mode2 2.16 2.69 2.17 2.16
Mode3 3.16 3.39 3.15 3.14
MACValues
Mode1 ‐ 0.99 0.99 0.99
Mode2 ‐ 0.89 0.99 0.99
Mode3 ‐ 0.91 0.98 0.98
» Calibrated models from both approaches match data accurately
» Crossing of the closely spaced modes made mode‐pairing challenging in the updating process
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Use of GBL and UAS at the Urban Scale
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Bungamati
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Bungamati: Flight Plan
~ 1600 High‐Definition Aerial Photos of Bungamati, Nepal
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https://www.youtube.com/watch?v=ey7jADUWrFk&feature=youtu.be
Bhaktapur
VIDEOVIDEO
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Reports and Data1. Akhlaghi, M., Bose, S., Moaveni, B., Stavridis, A. (2018). "Bayesian model updating of a damaged school building in Sankhu, Nepal." Proc. of 36th International Modal Analysis
Conference (IMAC‐XXXVI), Orlando, Florida, USA.2. Barbosa, A.R., Fahnestock, L.A., Fick, D.R., Gautam, D., Soti, R., Wood, R., Moaveni, B., Stavridis, A., Olsen, M.J., and Rodrigues, H., (2017). “Performance of Medium‐to‐High Rise
Reinforced Concrete Frame Buildings with Masonry Infill in the 2015 Gorkha Nepal Earthquake." Earthquake Spectra. Earthquake Spectra: December 2017, Vol. 33, No. S1, pp. S197‐S218. https://doi.org/10.1193/051017EQS087M
3. Bose S., A. Nozari, A. Stavridis, B. Moaveni. "Nonlinear modeling of the seismic performance of a building at Sankhu Nepal during the 2015 Nepal Earthquake," Proc. 16th World Conference in Earthquake Engineering, 2017.
4. Bose S., A. Nozari, M.E. Mohammadi, A. Stavridis, B. Moaveni, R. Wood, D. Gillins, A. Barbosa. "Structural assessment of a school building in Sankhu, Nepal damaged due to torsional response during the 2015 Gorkha Earthquake," IMAC XXXIV Dynamics of Structures, v.2, 2016, p. 31. doi:10.1007/978‐3‐319‐29751‐4_5
5. Bose S., A. Nozari, M.E. Mohammadi, A. Stavridis, B. Moaveni, R. Wood, D. Gillins, A. Barbosa.. "Structural assessment of a school building in Sankhu, Nepal damaged due to torsional response during the 2015 Gorkha Earthquake," IMAC XXXIV ‐Engineering Nonlinearities in Structural Dynamics, 2016.
6. Brando G., D. Rapone, E. Spacone, A. Barbosa, M. Olsen, D. Gillins, R. Soti, H. Varum, A. Arede, N. Vila‐Pouca, A. Furtado, J. Oliveira, H. Rodrigues, A. Stavridis, S. Bose, M. Fagella, R. Gigliotti, R. Wood.. "Reconnaissance report on the 2015 Gorkha Earthquake effects in Nepal.," Anidis Conference, 2015.
7. Brando G., D. Rapone, E. Spacone, A. Barbosa, M. Olsen, D. Gillins, R. Soti, H. Varum, A. Arede, N. Vila‐Pouca, A. Furtado, J. Oliveira, H. Rodrigues, A. Stavridis, S. Bose, M. Fagella, R. Gigliotti, R. Wood.. "Reconnaissance report on the 2015 Gorkha Earthquake effects in Nepal," XVI Convegno Anidis, 2015.
8. Brando, G., Rapone, D., Spacone, E., O’Banion, M.S., Olsen, M.J., Barbosa, A.R., Faggella, M., Gigliotti, R., Liberatore, D., Russo, S., Sorrentino, L., Bose, S., Stravidis, A. (2017). “Damage Reconnaissance of Unreinforced Masonry Bearing Wall Buildings after the 2015 Gorkha, Nepal, Earthquake." Earthquake Spectra. Vol. 33, No. S1, pp. S243‐S273. https://doi.org/10.1193/010817EQS009M
9. Nozari, A., S. Bose, B. Moaveni, a. Stavridis. "Finite element model updating and damage identification of a school building in Sankhu Nepal," Proc. 16th World Conference in Earthquake Engineering, 2017.
10. Rodrigues, H., Furtado, A., Vila‐Pouca, N., Varum, H., Barbosa, A.R. (2018). “Seismic Assessment of a School Building in Nepal and Analysis of Retrofitting Solutions.” International Journal of Civil Engineering. https://doi.org/10.1007/s40999‐018‐0297‐9
11. Varum H., A. Barbosa, A. Arede, A. Vila‐Pouca, H. Rodrigues, A.F. Furtado, J. Dias‐Oliveira, G. Brando, D. Rapone, E. Spacone, M. Olsen, D. Gillins, R. Soti, A. Stavridis, S. Bose, M. Fagella, R. Gigliotti, R. Wood.. "April 2015 Gorkha Earthquake in Nepal: field observations," 10th Congresso Nacional de Sismologia e Engenharia Sismica, 2016.
12. Varum H., A. Barbosa, A. Arede, A. Vila‐Pouca, H. Rodrigues, A.F. Furtado, J. Dias‐Oliveira, G. Brando, D. Rapone, E. Spacone, M. Olsen, D. Gillins, R. Soti, A. Stavridis, S. Bose, M. Fagella, R. Gigliotti, R. Wood.. "April 2015 Gorkha Earthquake in Nepal: field observations," 10th Congresso Nacional de Sismologia e Engenharia Sismica, 2016.
13. Wood, R.L., Mohammadi, M.E., Barbosa, A.R., Soti, R., Abdulrahman, L., Kawan, C.K., Shakya, M., Olsen, M.J. (2017). “Damage Assessment and Modeling of the Five Tiered Pagoda Style Nyatapola Temple." Earthquake Spectra. Vol. 33, No. S1, pp. S377‐S384. https://doi.org/10.1193/121516EQS235M
14. Yu H., A. Levine, M. Mohammed, T. van Oss, B. Moaveni, A.R. Barbosa, A. Stavridis. "System Identification and modeling of an 18‐story building in Nepal using post‐earthquake ambient vibration data," 16th World conference on earthquake Engineering., 2017.
15. Yu H., Mohammed M.A., MohammadiM.E., Moaveni B., Barbosa A.R., Stavridis A. and Wood R.L.. "Structural identification of an 18‐story RC building in Nepal using post‐earthquake ambient vibration data.," Front. Built Environ., v.3, 2017. doi:10.3389/fbuil.2017.00011
DesignSafe: https://doi.org/10.17603/ds2p082
Additional thoughts:Structural Geotechnical
Structural deformations\displacements\ deflections\rotations
Shear and other crack analysis (orientation, location, distribution, width (larger cracks), etc.)
Bridge collapse analysis Spalled concrete quantification Concrete wall blow‐out/in
failure analysis Permanent soil structure
impacts
Liquefaction\Lateral spreading Landslide\slope stability Coastal erosion Settlement Scour (depth distribution and
volume) Surface rupture Quay, retaining & sea wall failures Topographic analysis Sediment accretion Subsidence Geomorphic change detection
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Structural Engineering: Example Applications
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Acknowledgements
National Science Foundation Grant Number CMMI‐1545632 and 1545595
“RAPID/Collaborative Research: Post‐Disaster, Reinforced Concrete Building
Performance Data Collection following the April 25, 2015 Nepal Earthquake”
Kearney Faculty Scholar Endowment
Cascadia Lifelines Program
Dr. Manjip Shakya, Dr. Ganesh Ram Nhamafuki, Dr. Hemchandra Chaulagain,
Principal Chandra Kiran, Principal Sujan Maun, Sharoo Shrestha
Several building owners in Nepal that prefer to remain anonymous
Leica Geosystems and David Evans and Associates provided the Oregon State
University laser scanning equipment and software used for this project
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