Evaluation of Liquefaction Strength of Sand and Effect of Partial Drainage Using Pore Pressure Generation Model

Abstract

Differences in liquefaction strength due to variations in grain size can be explained in relation to volume change characteristics. However, the differences in grain size also affect the soil permeability, increasing the apparent liquefaction strength as the partial drainage effect. A pore pressure generation model predicts the excess pore pressure using the unique index of volumetric strain, thereby enabling the consideration of both volume change characteristics and partial drainage effect in a unified manner. In this study, triaxial tests were conducted using sands of different grain sizes, and the liquefaction strength was evaluated using the model. From the triaxial tests and the predicted results, it was confirmed that the differences in liquefaction strength could be explained by the plastic volumetric strain and elastic modulus of the sand. Furthermore, a series of centrifuge tests was conducted to verify the increase in apparent liquefaction strength due to the partial drainage effect. The increase in liquefaction strength could be evaluated based on the volumetric strain due to the partial drainage.