Pile and Pile-Group Response to Liquefaction-Induced Lateral Spreading in Four Large-Scale Shake-Table Experiments

Four large laminar-box shaking table experiments are conducted to document pile response due to the mechanism of liquefaction-induced lateral spreading. Single-pile and pile-group configurations are tested in a mildly inclined ground configuration. Two ground profiles of about 5 m in height are investigated, one with a liquefiable saturated sand stratum and the second with an added upper crust. The recorded data sets from this series of experiments are analyzed collectively to document and track the evolution of lateral loading on the deployed pile and pile-group configurations. Ground and pile lateral displacement as well as excess pore pressure are discussed. In this series of tests, it is observed that some of the highest pile lateral loads occur at the initial stages of lateral deformation, as the excess pore pressures approach the level of liquefaction. Thereafter, lateral load might decrease with further shear strength reduction and deformation in the liquefied stratum. For such soil profiles, lateral ground deformation that continues to accumulate due to the shaking process may not always result in significantly larger loads on the embedded pile foundation.