Drained cavity expansion analysis with a unified hardening (UH) model for clays and sands

Abstract

This study presents a novel semi-analytical solution for the drained expansion of cylindrical and spherical cavities with a unified hardening model for both clays and sands (CSUH). The three-dimensional strength of soils is considered using the stress transformation method. Large-strain analyses are incorporated into the developed cavity expansion solution to obtain the entire stress-strain histories of soils in the plastic regions. By formulating the problem as an initial value problem in the Lagrangian scheme using an auxiliary independent variable, the present study solves the problem numerically. A thorough parameter analysis is conducted for both cylindrical-spherical and clay-sand scenarios, and the results are compared with other existing solutions to demonstrate the distinctive attributes of the present solution. It is found that the present solution can effectively capture the evolution processes of both strength and overconsolidation characteristics of soils, as well as the contracting and dilating behaviors of soils. Three key advantages of the present solution are its sufficient accuracy, less and easily determined parameters, and broad applicability in both clays and sands, resulting in extensive application in engineering, including tunneling, pile foundation construction, and cone penetration tests in clay-sand scenarios under drained conditions.