Calculation of Displacement-Dependent Active Earth Pressure for Deep Excavations in Soft Soil

Abstract

In the urban environment, there are strict control requirements for deep foundation pit deformation, resulting in earth pressure on the flexible supports often being in a nonlimiting state. Therefore, it is important to consider displacement when calculating earth pressure. In this study, lateral unloading stress path triaxial compression tests were performed to investigate the radial stress–strain relationship of soft clay in an active region. Herein, a displacement-dependent earth pressure model is proposed with the assumption of the soil strain distribution in the disturbed area. From the surface of the ground to the deepest part of the support structure, the sufficient active displacement inversed by the proposed model decreased, which confirmed that the earth pressure along the entire wall could not achieve its active conditions simultaneously. The efficacy of the proposed model is demonstrated through a comparison of the predicted earth pressure with the experimental results reported in the published literature.