RAPID: Geotechnical-driven Damage Patterns and Liquefaction in the January 2010 Haiti Earthquake

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

This Rapid Response Research (RAPID)award provides funding to allow the investigators to augment previous, limited-scope DCPT and Vs investigations with additional and deeper investigations into the effects of the Haiti earthquake. The magnitude 7.0 earthquake that struck Haiti on January 12, 2010 caused tremendous damage to the built and natural environment, destroying buildings, crippling the Port-au-Prince seaport, and causing large coastal, roadway, and slope failures. The PIs participated in a reconnaissance trip to Haiti as part of a Geo-engineering Extreme Event Reconnaissance team. The team published preliminary findings at: http://www.geerassociation.org/GEER_Post%20EQ%20Reports/Haiti_2010/Cover_Haiti10.html. The team brought back an extensive set of data from this initial reconnaissance, including shear wave velocity (Vs) and dynamic cone penetration test (DCPT) data at several sites. However, after an initial damage assessment and an evaluation of preliminary findings, a number of critical details that require further investigation have been identified. Given the tremendous damage that resulted from this earthquake, it is imperative that the profession maximize what is learned from this event in order to minimize damage during future earthquakes in Haiti, in other developing coastal nations, and elsewhere around the world. The intellectual merit of this activity is threefold. (1) The team will augment previous, limited-scope DCPT and Vs investigations with additional and deeper investigations, as well as soil sampling and lab testing to understand liquefaction in carbonate sands, as these sands are poorly represented in the worldwide liquefaction case history database despite their worldwide presence. This work will chiefly involve sampling and testing along the southern coast of Port au Prince Bay, primarily between Leogane and Petit Goave, and along the major rivers north of Port au Prince. Subsequent lab testing will include ring shear and cyclic triaxial testing. (2) The team will expand initial observations of potential topographic effects on damage patterns on the hillsides and slopes in communities surrounding Port-au-Prince, such as Petion-Ville. This effort will involve collecting slope strike and dip angles, proximity to ridge tops, and obtaining shallow Vs measurements in areas identified with noticeable damage patterns apparently influenced by topography. (3) The team will collect 15 to 20 near-surface Vs profiles in low-lying areas of Port-au-Prince where potential soft-soil amplification effects leading to noticeable damage patterns are observed. These measurements will be spatially-distributed in both areas that suffered heavy damage and areas that suffered minimal damage. These efforts will be enhanced using innovative 3D imaging software and calibrated digital cameras to develop 3D digital elevation models of damage at these sites. The broader impacts of this project are focused on training students and improving the state-of-practice of engineering. Each team member will bring one graduate student to train them to perform reconnaissance and will encourage them deliver seminars about their experiences and the team will interact with personnel from Ministry of Mines and Natural Resources in Haiti. Additionally, the team will publish findings on liquefaction of carbonate sands, topographic effects, and site effects. Evaluating geophysical data and laboratory testing of samples recovered at select sites will also involve training graduate and undergraduate students. This award is co-funded by the NSF Office of International Science and Engineering (OISE).