Interpretation of pore pressure dissipation of CPTu in intermediate soil considering partial drainage effect

Abstract

The degree of drainage that occurs during structure-soil interaction is a crucial factor that affects the stress on the structure in the intermediate soil. The consolidation coefficient is the most important index to evaluate partial drainage conditions, but the pore pressure dissipation curve used for consolidation coefficient inversion is also affected by drainage conditions. This paper adopts an effective stress numerical analysis work which combines finite-element penetration analysis and critical-state soil mechanics considering the partial drainage effect through changing the penetration rate. The significant advances of this work are the evaluation of the partial drainage effect on pore pressure test data and the influence mechanism of partial drainage on consolidation coefficient test results of intermediate soil. A modified consolidation coefficient inversion method can describe the pore-pressure response curve for dissipation tests performed in soils where pore pressure has dissipated partially. The modified theoretical relationship of vertical and horizontal consolidation coefficient and the theoretical relationship of ch under partial drainage and undrained condition are given. The consolidation coefficient inversion method of intermediate soil with high permeability is proposed, and the inversion results are consistent with the actual value.