Simulation of lateral spreading of gently sloping liquefied ground

This paper is focused on the simulation of the lateral spreading phenomenon and the anticipated maximum surface displacements of sloping ground. An innovative numerical methodology is proposed employing a generalized plasticity model implemented in a nite element code, which has been thoroughly validated against VELACS centrifuge liquefaction experiments. Lateral spreading is the term used to refer to the development of large horizontal ground displacements due to earthquake induced liquefaction, in the case of even small free ground surface inclination or small topographic irregularities. Recent earthquakes have emphasized the fact that this phenomenon has signicant practical importance for civil engineering structures (coastal structures, bridge piers, lifelines, etc.), since it imposes considerable lateral loads and may lead to widespread failures. Fortunately, there exist methods today which can be used for the design of such structures against lateral spreading (e.g. P-y analysis). However, their accuracy depends greatly on the ability to estimate the anticipated lateral ground displacements and their variation with depth. In this research, a fully coupled two-dimensional dynamic analysis based on effective stress formulation using saturated porous media considering uid movement has been used to simulate the lateral spreading and evaluate the amount of deformations occurred in liquefiable soils. The governing equations are developed for saturated porous media based on the extension of Biot formulation. The cyclic elastoplastic behavior of soil under earthquake loading is modeled using the generalized plasticity theory composing of a yield surface together with non-associated ow rule proposed by Pastor and Zienkiewicz. A fully explicit dynamic finite element method and a fully coupled (u-w) formulation are employed in a computer code to analyze soil displacements and pore water pressures (Taslimian et al., 2014). In order to ensure the accuracy of numerical analysis results, a centrifuge experiment results has been utilized. The results of numerical analysis compared with experimental measurements indicate that the proposed numerical model has the capability to simulate the lateral spreading phenomenon. The same finite element mesh was used for all numerical simulations, as shown in Figure 1.