Active earth pressure analysis of finite soil mass under excavation conditions of adjacent foundation pits

Fang Kai; Wang Shuo; Liu Nianwu

doi:10.16186/j.cnki.1673-9787.2024010009

Abstract：Objectives When adjacent foundation pits are excavated simultaneously,the deformations of fi-nite soil between the pits on both sides influence the distribution of earth pressure.A rational analysis and determination of the characteristics of finite soil pressure have become crucial issues in engineering.Meth-ods To characterize the soil pressure of finite soil under the condition of adjacent foundation pit excavation,the deformation patterns of finite soil during simultaneous excavation of adjacent pits and the mechanisms by which excavation affects soil pressure development were analyzed using the discrete element method.By conducting stress analysis on soil elements in different regions,an analysis model for active soil pressure of finite soil during excavation of adjacent foundation pits was constructed,and the characteristics of soil pres-sure under varying retaining wall displacements were evaluated.Results The results show that the displace-ment field and slip mode of finite soil differ from those under unilateral foundation pit excavation.Com-pared with unilateral excavation,the earth pressure on retaining walls under simultaneous excavation of ad-jacent pits is smaller.The difference in earth pressure between the two cases is influenced by the aspect ra-tio of the finite soil and the displacement of the retaining wall,the smaller the aspect ratio,the greater the pressure difference.As the retaining wall displacement increases,the pressure difference first increases and then decreases.When the wall displacement reaches half of the displacement required for the overall active limit state of the soil,the pressure difference reaches its maximum.Conclusions The proposed method can effectively characterize the distribution of earth pressure under simultaneous excavation of adja-cent foundation pits,providing theoretical support for calculating active earth pressure of finite soil under the influence of displacements of retaining walls on both sides.