The M 7.8 Gorkha Earthquake occurred at 11:56am local time in Nepal on April 25, 2015. This earthquake and the many aftershocks that followed significantly affected Nepal, causing human losses as well as widespread structural damage and ground failure. The building stock in the affected regions predominantly consists of poorly engineered unreinforced masonry buildings. However, approximately 25% of the buildings consist of reinforced concrete (RC) frames infilled with masonry walls.This structural system was widely employed in the 1920’s and 1930’s in California as well as in the Pacific Northwest; hence, understanding their failure mechanisms has direct implications for a large number of buildings in metropolitan areas in the United States (US).
This project focuses on post-earthquake assessment of existing RC building frames with masonry infill in Nepal. The team will acquire, process, and archive architectural and structural data, including building drawings, in residential buildings and critical facilities such as schools and hospitals. The data will be obtained through traditional methods as well as geo-referenced, 3D, ground-based lidar (GBL) scans and Structure from Motion (SfM), i.e. 3D reconstructions from 2D photographs, thus providing detailed, quantitative damage measurements. This collected data will provide new earthquake reconnaissance case studies of RC frame with infill buildings and will be used to evaluate current US guidelines for assessment of existing structures. Moreover, it will serve to inform local rebuilding and recovery efforts in Nepal though close collaboration with local agencies in Nepal.
The research team collaborated with researchers and practicing engineers from the US, Italy, Portugal, and Nepal. Hence, beyond its intellectual and technical merit, this project provides foreign research experiences to three graduate students and further strengthens ties between the scientific research communities in the United States, Nepal, and the European Union.
NSF-RAPID Project Team:
Oregon State University
People: Dr. Andre Barbosa (PI), Dr. Mike Olsen (co-PI), Dr. Dan Gillins, Rajendra Soti, Patrick Burns, and Matthew Gillins;
Tasks: Coordination, detailed structural assessment of RC frames with infill, ambient vibration testing;
Equipment: Total GPS stations, Laser Scanning Equipment, Unmanned Aerial Vehicles (UAVs), 360 panoramic camera (Thanks to PEER), rebar scanners, Schmidt hammer, and cables and connections for PCB accelerometers and DAQ for ambient vibration testing
University of Buffalo
People: Dr. Andreas Stavridis (co-PI) and Supratik Bose;
Tasks: Detailed structural assessment of RC frame with infill, ambient vibration testing;
Equipment: Accelerometers for ambient vibration testing
NSF-RAPID Project Collaborators:
University of Chieti-Pescara, Italy
People: Dr. Enrico Spacone, Dr. Giuseppe Brando, Davide Rapone;
Tasks: Assessment of reinforced concrete structures and vulnerability assessment of masonry structures.
Equipment: Rebar scanners, Schmidt hammer, ultrasonic testing for concrete
University of Roma, La Sapienza, Italy
People: Dr. Rosario Giglioti and Dr. Marco Faggella;
Tasks: Earthquake damage assessment
University of Porto, Portugal
People: Dr. Humberto Varum, Dr. Nelson Vila Pouca, Dr. Hugo Rodrigues, Andre Furtado, and Joao Oliveira;
Tasks: Assessment of RC frames with infill, and monuments;
Equipment: Three seismometers with data loggers and five accelerometers for measuring wall panel vibration characteristics
University of Nebraska, Lincoln
People: Dr. Richard Wood;
Tasks: Laser scanning and ambient vibration testing for assessment of RC frames with infill, vulnerability of historic centers, and monuments;
Equipment: Laser scanning equipment and UAVs
Tufts University
People: Dr. Babak Moaveni;
Tasks: Ambient vibration data processing;
Equipment: Accelerometers and DAQ
National Society for Earthquake Technology, Nepal
People: Dr. Ramesh Guaragain, Surya Naryan Shrestha, Dev Kumar Maharjan
PEER – Pacific Earthquake Engineering Research Center
People: Dr. Stephen Mahin, Grace Kang
Tasks: Webinar support and database development;
Equipment: Panoramic 360 camera
NSF-RAPID Acknowledgements:
The project team and collaborators would like to acknowledge the support of several people and institutions, including:
- Dr. Benson Shing, University of California San Diego
- Dr. Janise Rodgers, Geohazards International
- Dr. Albert Lin and Dr. Luke Barrington, Digitalglobe
- Khwopa Engineering College (Dr. Manjip Shakya, Dr. Ganesh Ram Nhamafuki, Chandra Kiran Kawan)