Induced Partial Saturation (IPS)
Liquefaction Mitigation
NSF / NEESR Project

Abstract:

Mitigation of liquefaction-induced damage to the built environment continues to be an important priority and a major challenge in civil engineering. There is an urgent need to develop cost-effective liquefaction mitigation measures that can be applied to new sites as well as sites with existing structures.

The PI and Co-PI have been conducting laboratory research to explore the development of an innovative method for liquefaction mitigation based on induced partial saturation (IPS) in otherwise fully saturated liquefiable sands. The research to date has demonstrated the technical feasibility of the method. Laboratory tests have led to the conclusion that introduction of gas bubbles in sands, thus reducing its degree of saturation, prevents the occurrence of liquefaction.

Intellectual Merit:

To further advance IPS as a liquefaction mitigation measure to be considered by the professional engineering community in practice, a comprehensive research and verification program is proposed with testing in large-scale laboratory and field experiments. The goal of this proposed research is two folds: 1) to conduct fundamental research exploring the feasibility of inducing partial saturation under field conditions, by injecting very low concentration of sodium percarbonate solution and (through flow, transport, and reactivity processes) slowly generate oxygen gas bubbles in sands, and 2) to demonstrate the effectiveness of IPS in preventing the occurrence of liquefaction. The proposed research takes advantage of the unique experimental and field facilities of NEES to acquire fundamental knowledge on the behavior of IPS in sands and to develop enabling technologies to verify the effectiveness of IPS as a liquefaction mitigation measure. The research program will achieve its goal by integrating small- and large-scale laboratory investigations, field tests, and numerical simulation. The research outcomes will advance IPS as a cost-effective liquefaction mitigation measure for new sites and, more importantly, for sites with existing structures.

The research team is composed of experts in the geotechnical earthquake engineering and liquefaction, and the geoenvironmental field. The program includes small-scale laboratory tests and numerical simulations at Northeastern University, tests using NEES@Buffalo’s large laminar box, preliminary field tests at Northeastern University and at Boise State University (utilizing their drilling rig and equipment), and field research and verification of the effect of IPS on liquefaction using NEES@UTexas T-Rex at the NEES@UCSB Wildlife Refuge.

Broader Impact:

The outcome of this research will advance efforts at developing a cost-effective liquefaction mitigation measure that will have world-wide impact on human safety and protection of property from earthquake hazards. Also, oxygen delivery is of interest in geoenvironmental engineering, and this research will be valuable for improving in-situ implementation of bioremediation. The research is a collaboration between faculty and students in the fields of earthquake and geoenvironmental engineering. Such collaborations will benefit undergraduate and graduate students in engineering and promote interdisciplinary education and research. The EOT program will include laboratory and field demonstrations and videos of the beneficial effects of IPS in preventing liquefaction-induced building failure. These educational tools will also be used to heighten the public’s awareness of earthquake risk. Outreach activities of the project team will include participation in institutional programs of their universities such as Women in Engineering, Building Bridges, STEM Education, Program in Multicultural Engineering, NSF Young Scholars summer program, Upward Bound Summer Internship, and Louis Stokes Alliance for Minority Participation (LSAMP) programs.

Prof. Akram Alshawabkeh
Northeastern University

Co-PI: Transport and reactivity to generate oxygen bubbles; analytical simulation; IPS delivery system

Dr. Cliff Voss
USGS, CA

Advisor: Scientific and programing support to complete development of SUTRA-Bubble simulation program

Kurt Braun
Senior Machinist

Partially Saturated Sand Behavior