Geotechnical Failures in Chile

Dr. Dominic Assimaki is an assistant professor in the School of Civil and Environmental Engineering at Georgia Tech who traveled to Chile after the devastating 8.8MB earthquake on February 12, 2010. Dr. Assimaki is a member of the Geo‐engineering Extreme Events Reconnaissance (GEER) organization, a group of experts dedicated to developing a systematic approach to conduct NSF‐sponsored reconnaissance efforts of the geotechnical effects of extreme events. GEER focuses on collecting data from post‐earthquake reconnaissance to support advancements in research, the state‐of‐the art, and the state‐of‐practice of geotechnical earthquake engineering.

Working with the second team sent in by GEER (Team B), Assimaki and colleagues were responsible for documenting geotechnical failure case studies. Her team's documentation was based on the observations and recommendations of the advance team, Team A.

Team B was lead by Jonathan Bray (UC Berkeley) and included Tara Hutchinson (UC San Diego), Pedro Arduino (University of Washington), Jonathan Stewart (UC Los Angeles), George Mylonakis (University of Patras, Greece), Kyle Rollins (Briham Young University), Laurie Johnson (Johnson Consulting, San Francisco), Rob Witter (USGS), as well as Dominic Assimaki. Team members worked in collaboration with Professor Ramon Verdugo (Universidad de Chile), Professor Christian Ledezma (Pontifica Universidad Catolica de Chile), and Dr. Terry Eldridge (Golder Associates). Additional members of the team included Chilean civil engineering students who assisted with navigation across the country and translation with locals and authorities.

One of many buildings destroyed on the coast of Chile by the 2010 earthquake.Team B was divided into three groups after arriving in Santiago on March 13. CEE Professor David Frost briefed team members on the reconnaissance results of Team A. The next day, Assimaki's group visited Ciudad Empresiarial, a neighborhood located north of Santiago that includes many newly constructed, high‐rise buildings and five damaged bridges on the ring highway around the city (Avenue Americo Vespucio). Other sites included the port of San Antonio, and Vina del Mar, a coastal summer resort north of Santiago. On day two, the team traveled to the port of Valparaiso, which is located south of Vina del Mar. At this site, they were able to complete documentation of damage in this resort town.

On the third day, Team B traveled south along Hwy 5 to document the extensive damage to bridges, embankments, and railroad overpasses (as seen in Photo 1). On Mar 17, the group headed south of Conception to the port of Coronel. This site incurred much more extensive damage than the previous locations due to its location closer to the epicenter (Photo 2). After carefully documenting the damage in this area, the team continued to move south, past the town of Lota, to the coastal town of Arauco where the tsunami caused extensive damage (Photo 3). The team continued to document damage as far south as Tupal where they evaluated a bridge site with critical damage (Photo 4). The team's last day in the field was spent in Talca, where the epicenter occurred. According the Assimaki, the extent of damage was unyielding.

The data collected by GEER Teams A and B will be readily used for the assessment of established Structural damage to bridges and roadways in Chile. numerical models/procedures and building code provisions. In addition, it will lead to improvements in the understanding and predictive tools designed and used to mitigate hazard and reduce risk from future earthquakes. The GEER Association is dedicated to developing a systematic approach to conduct NSFsponsored reconnaissance efforts of the geotechnical effects of extreme events.

GEER focuses on collecting data from post‐earthquake reconnaissance in an effort to support advancements in research, the state‐of‐the art, and the state‐of‐practice of geotechnical earthquake engineering.

For additional information, visit http://www.geoquake.gatech.edu/.