Deformation Characteristics Prediction for Asymmetric Retaining Structure Systems in Adjacent Excavations

This paper investigates the influence of different asymmetric retaining structure systems on deformation behavior and environmental impact in adjacent excavations using three-dimensional finite difference analysis. A simplified method for calculating non-limiting soil pressure in a finite-width soil mass is developed by integrating active earth pressure theory. The response of adjacent retaining walls and the surrounding environment is assessed using an improved beam–spring model that accounts for the distribution characteristics of non-limiting soil pressure. A three-dimensional numerical model is established to simulate the interaction between adjacent excavations effectively. The study analyzes the distribution of soil pressure, surface settlements, retaining wall deflections, and the effects of varying distances between adjacent excavations across different retaining structure systems. Results show that soil pressure in the non-limiting state varies with pile displacement and that nonlinearly distributed pressure decreases with increasing excavation depth. The surface settlement from the post-construction excavation is significantly influenced by the superposition effect, although its maximum value is smaller than that of the pre-construction excavation when different retaining structures are considered. The maximum deflection of retaining structures occurs at the excavation depth, and the land-side wall experiences less displacement in post-construction scenarios. Additionally, reducing the spacing between adjacent excavations leads to smaller surface settlements and only a slight increase in maximum retaining wall deflection due to the soil arching effect.