Liquefaction Mitigation Using Entrapped Air

Northeastern University, Boston MA

Investigators

Abstract

Abstract Incidents of liquefaction of loose saturated sands have been observed in almost every past moderate to large size earthquakes worldwide. Damage to engineered structures due to foundation soil liquefaction haas been dramatic and devastating. Mitigating liquefaction-induced damage to new and, more importantly, to existing structures in urban communities remains a major challenge. The primary objective of the proposed research is to investigate the scientific and technical feasibility of using entrapped air in liquefaction susceptible sands to mitigate potential earthquake-induced damages. The research will focus on developing an in-depth experimental and analytical understanding of the beneficial effect of introducing small amounts of air on the behavior of liquefaction susceptible sands under seismic excitations. This research program has a number of specific objectives that include: 1. Developing a unique experimental set-up that will integrate advanced sensing technologies including radar and bender elements with generation of gases using electrolysis, with a shaking table facility to permit cyclic and earthquake testing of saturated and air-entrapped sands. 2. Developing a fundamental understanding of the behavior of sand-water-gas mixtures subjected to seismic excitations. 3. Demonstrating that entrapped air can significantly reduce the liquefaction potential of sands, and holds promise as a cost-effective and readily applicable liquefaction mitigation measure. 4. Identifying the important areas of field research that must be conducted to advance the proposed mitigation measure for adoption in engineering practice. This research program and the shaking table facility will be utilized to enhance the awareness of urban communities to the potential devastating effects of natural disasters, in particular of earthquakes. A component of the research program is to reach out to high school students and to demonstrate the crucial role that engineers play in disaster mitigation. The goal of the outreach activities is to help improve disaster preparedness of our communities, and to attract bright students, especially women and minorities, into the field of engineering.