Seismic liquefaction and rehabilitation of large earth dams in US

Earthquake induced liquefaction is a major concern for embankment dam safety. The U.S. Army Corps of Engineers (USACE) has responsibility for the safe performance of over two hundred dams in high seismic hazard areas of the U.S. The USACE periodically evaluate the safety of these dams against expected seismic events in the light of new hydrologic or seismic data or changes in the state-of-the-art design or construction criteria. Those dams that are found deficient are retrofitted through appropriately designed remediation methodologies. One of the major seismic safety problems for the dams is liquefiable foundation deposits. This paper is focused on the USACE experience in dynamic stability evaluation and remediation of earth dams with liquefiable foundations. Several major earth dam remediation case histories are discussed. Furthermore, the current state-of-the-art in retrofit ground improvement for liquefiable dam soil deposits is provided.