Modeling the Response of a Pleistocene Sand during In Situ Liquefaction Testing

摘要

The results of a numerical study to predict the response of a Pleistocene uncemented sand deposit during an in situ liquefaction test with a mobile field shaker are presented in this paper. A plasticity model is used to represent cyclic stress-strain behavior of the sand. Input model variables are calibrated using results from field geotechnical testing and laboratory monotonic triaxial testing of intact specimens obtained by in situ freezing. The calibration required considerable adjustment of one primary input variable to account for increased liquefaction resistance due to aging processes. The simulations under amplitudes representative of the mobile shaker's highest output predicted an initial tendency towards contraction and maximum excess pore pressure ratios (r_u) of < 20%, followed by a dilative response and subsequent reduction in pore pressure.