Energy-based liquefaction assessment in sands and silty soils

Liquefaction phenomenon involves progressive contact deformation, slip, reorganization of contacts, and eventual collapse of soil skeleton. During the process leading to liquefaction energy is continuously lost mainly along frictional contacts. Many researchers identified the cumulative energy lost up to liquefaction as a useful index for liquefaction potential assessment. In this paper a theoretical model for estimating the frictional energy loss in soils during cyclic loading of saturated soils is presented. The nature of soil structure, mobilization of friction, and the occurrence of slip along the contact surfaces have been studied and incorporated in this model. This model is validated using experimental data for three sands and sand-silt mixes. A new pore pressure model based on energy dissipation is introduced. Based on above developments and understanding, a numerical simulation model is developed to simulate energy dissipation, pore pressure generation, pore pressure dissipation, and densification in a saturated soil deposit subjected to an earthquake shaking. The results are compared with data from centrifuge model tests.