Earth pressure on rotating-about-top excavation retaining walls adjacent to existing structures

The load transfer mechanism and failure mode of narrow soils induced by rotating about the top of excavation retaining structures (RT displacement mode) are investigated using the Finite Element Limit Analysis (FELA) method with the Hardening Mohr-Coulomb (HMC) model. A logarithmic spiral curve model is innovatively proposed to accurately characterize the evolution of the failure surface in narrow soils behind retaining structures under RT displacement mode based on numerical simulation results. Through analysis of principal stress vector diagrams obtained from FELA simulations, an asymmetric soil arching effect is identified in the upper zone of the narrow soils behind the retaining structure. An optimized differential element method is developed by constructing asymmetric arched differential elements along the deflection of principal stresses at the soil’s limit state, thereby establishing an analytical framework for calculating earth pressure in narrow soils under RT displacement mode. The proposed analytical method is validated through favorable agreement with finite element analysis results. Additionally, sensitivity analyses are performed to evaluate the effects of soil strength parameters, interface friction angles, and aspect ratios on earth pressure distribution, earth pressure coefficients, and the location of the resultant thrust.