A team of earthquake researchers, sponsored by the Earthquake Engineering Research Institute (EERI) and the Geo-Engineering Earthquake Reconnaissance (GEER) Association, carried out a field investigation in conjunction with Chinese colleagues from August 4th to 10th to document scientific and engineering effects of the devastating earthquake (moment magnitude 7.9 according to the USGS) that occurred in Wenchuan County of Sichuan Province, China, on May 12, 2008. The EERI field investigation was conducted as part of the Learning from Earthquakes Program with funding from the National Science Foundation (NSF).

The EERI-GEER field investigation team was invited by Prof. Zifa Wang, Director of the Institute of Engineering Mechanics-China Earthquake Administration (IEM-CEA), to investigate the effects of the Wenchuan earthquake. During the short period of one week in the field, the EERI-GEER team could only get a small sample of the effects of the great earthquake. Prof. Junwu Dai of the IEM-CEA accompanied the team during the field investigation.

This presentation will show observations made during the EERI-GEER field investigation in Sichuan Province as well as observations made by other investigators who have visited the earthquake-affected region. The earthquake originated in the rugged Longmenshan Mountains, which form the transition between the Tibetan Plateau and the Sichuan Basin. The Tibetan Highlands were formed as a result of the collision of the Indian Subcontinent with the Eurasian Continent. The Longmenshan Mountains are characteristic of a massive thrust fault system which is capable of great earthquakes. Massive rock movements and landslides resulted in the earthquake as well as strong ground motions with long duration. Massive destruction was caused to structures and infrastructure and there were about 90,000 deaths with hundreds of thousands of injuries.

Dr. Marshall Lew has been with MACTEC Engineering and Consulting, Inc. (and its predecessors) for almost 30 years and is a Vice President and Senior Principal of the firm. Dr. Lew obtained his Ph.D. in structural engineering from UCLA and is a registered Civil and Geotechnical Engineer in California and is a registered Professional Engineer in ten other states. Dr. Lew has practiced geotechnical and earthquake engineering in the western United States and internationally. Dr. Lew has been involved with pioneering efforts in seismic isolation technology having been on the design teams for the earliest base isolation projects in the United States (including the Foothill Communities Law and Justice Center and the University of Southern California's University Hospital). Dr. Lew is a member of ASCE, Structural Engineers Association of Southern California, Earthquake Engineering Research Institute (Secretary-Treasurer), Los Angeles Tall Buildings Structural Design Council (Current President), Asian American Architects and Engineers Association, Seismological Society of America, California Engineers and Land Surveyors Association of California, and the Council on Tall Buildings and Urban Habitat. Dr. Lew has published over many technical papers and has led geotechnical earthquake investigation teams for several recent earthquakes in the United States and abroad including Loma Prieta, Chi-Chi, Taiwan, and Great Wenchuan earthquakes.