The aim of this research project is to investigate (1) the effect of ground motion on ground response, including earthquake motions sufficiently severe to induce liquefaction and (2) the associated soil- pile interaction effects in liquefied soil deposits. Loose and dense sand and salt samples will be subjected to horizontal shaking similar to recorded earthquake accelerograms. Instrumented model piles and pile groups will be installed in the saturated soil for the study of dynamic soil-pile interaction. The models will be tested in the geotechnical centrifuge at the California Institute of Technology, and the model tests will simulate a prototype soil deposit with a depth of approximately 100 feet and subjected to ground accelerations in the range .05 to 0.5g. The objective of these tests is to determine: (1) the effects of strain levels on ground motions, (2) the ability of existing theories to predict the observed linear and nonlinear soil behavior, and (3) the conditions that lead to liquefaction and large permanent ground displacements. The realization of these objectives will contribute significantly to current procedures for assessing ground failure due to liquefaction as well as to the methods used to design piles in offshore areas located in seismic environments. Professor Scott is internationally recognized in this area of research and has the institutional facilities available to conduct the research. It is recommended that this request for support be approved.
