ASCE and the Geo Institute have each individually contributed $25,000 as sponsors of the State of the Art and Practice in Earthquake Induced Soil Liquefaction Assessment, a National Research Council project that will solicit input from the technical community and critically examine the technical issues regarding liquefaction hazard evaluation and consequence assessment.
“Opinions on how to evaluate liquefaction potential have diverged since a consensus was reached among geotechnical professionals at workshops in 1996 and 1998, and new methods of evaluating liquefaction and its consequences have emerged since that time,” says Edward Kavazanjian Jr., Ph.D., P.E.., D.GE, NAE, F.ASCE, professor at the School of Sustainable Engineering and the Built Environment at the Ira A. Fulton School of Engineering at Arizona State University, and senior sustainability scientist at the Julie Ann Wrigley Global Institute of Sustainability. “Therefore, it was felt that a new community-wide assessment of the state of the art and practice is warranted.” Kavazanjian chairs the National Research Council committee formed to conduct the study.
The study will assess and evaluate:
- Sufficiency, quality, and uncertainties associated with laboratory and in situ field tests, case histories, and physical model tests to develop and assess methods for determining liquefaction triggering, and the resulting loss of soil strength and its consequences.
- Methods to conduct and analyze laboratory and physical model testing and to collect and analyze field case history data to determine both the triggering of liquefaction and postliquefaction soil behavior (e.g., strength loss, dilation, and hardening).
- Adequacy and accuracy of empirical and mechanistic methods to evaluate liquefaction triggering and postliquefaction deformations of earth structures and structures founded on or in the earth, such as large embankment dams, levees, dikes, pipelines, highway embankments, bridges, pile-supported decks, and other structural foundations. Effects at large depths and high static shear stresses on liquefaction triggering and postearthquake shear strength will be among those addressed.
The study will focus on developments since the 1996 National Center for Earthquake Engineering Research (NCEER) workshop and the 1998 National Science Foundation/NCEER workshop on liquefaction issues. Inherent characteristics associated with the data (e.g., uneven distribution, scarcity, uncertainty) will be investigated.
The study will include a workshop on data gathering, vetting of field and laboratory data, and new developments in the assessment of earthquake-induced soil liquefaction. The final report will assess the state-of-the-art and practice for liquefaction analyses and address future directions for research and practice related to (1) collecting, reporting, and assessing the sufficiency and quality of field case history observations as well as in situ field, laboratory, and model test data, (2) addressing the spatial variability and uncertainty of these data, and (3) developing more accurate tools for assessing liquefaction triggering and its consequences.
In addition to ASCE and the Geo Institute, the project is also sponsored by the Bureau of Reclamation, U.S. Nuclear Regulatory Commission, the Port of Long Beach, the Port of Los Angeles, the Los Angeles Department of Water and Power, and the Federal Highway Administration. The project is expected to be completed in 2015.