Seismic response of liquefiable sloping ground: Class A and C numerical predictions of centrifuge model responses

Numerical simulations of the LEAP centrifuge tests are performed to validate the numerical modeling approach and to provide insight on our capacity to simulate and predict the equivalent field responses. Measured and recorded dissipation patterns, accelerations, and displacements for a sloping ground of medium dense Ottawa Sand subjected to a sinusoidal acceleration input motion are compared to Class A and C [12] numerical predictions performed in FLAC using the constitutive model PM4Sand. The constitutive model calibration process is based on two cases of cyclic strength for the sand and is performed against the available laboratory data as well as published data for Ottawa sand. Computed results are illustrated for selected cases and compared to measurements. Key observations, mechanisms, and time histories are reasonably captured and bounded by the simulations showing that FLAC, PM4Sand as well as the overall employed methodology have the capability to predict the response of liquefiable sloping ground. The soil properties are found to be playing the most important role in capturing the finer details of the response, and parametric investigations of the soil stiffness and permeability are further needed to refine the predictions.