Effects of Spatial Variability on Liquefaction-Induced Settlement and Lateral Spreading

Nonlinear dynamic numerical simulations of infinite slopes are used to examine the effects of spatial variability in penetration resistances on liquefaction-induced settlement and lateral spreading for gently sloping ground and to develop guidance on selecting representative properties for uniform models. Simulation results for models having uniform properties (uniform models) are compared to results for models having spatially correlated Gaussian random field property distributions (stochastic models). Results are presented for sets of stochastic model realizations and a set of ground motions scaled to a range of peak ground accelerations. Computed responses and ground deformations (settlements and lateral displacements) for these uniform and stochastic models are used to identify representative properties (as a percentile of the stochastic distributions) for which the uniform models produce reasonable agreement with the median of the stochastic model responses. The effects of the scales of fluctuation, nonliquefiable crust layer thickness, sand layer thickness, ground motion characteristics, sand density, and other factors are evaluated. Implications for engineering practice are discussed. (C) 2016 American Society of Civil Engineers.