Normalized analysis of deformation for deep excavation diaphragm walls under different neighboring building conditions

Abstract

This study investigates the impact of neighboring buildings on diaphragm wall deformation during deep excavation for building foundations. Prior numerical analyses predominantly utilized surface loading models, overlooking the influence of neighboring basements. Employing the finite-element method with PLAXIS 3D AE software, we assess the effects of neighboring structures on deep excavation. Our simulation adopts the top-down construction method, employing plate elements to represent diaphragm walls Temporary retaining support measures are implemented using H-shaped steel assemblies with preloaded anchors to simulate realistic excavation conditions. Neighboring building structures are accurately modeled using plate elements. Our findings reveal that the lateral displacement of the diaphragm wall varies with the depth of neighboring basements. At depths approximately half that of the excavation depth, the displacement significantly increases, reaching approximately 1.7 times the excavation depth and stabilizing thereafter. When neighboring buildings are about twice the excavation depth away, the deformation curve of the wall converges to that of "no loading," suggesting negligible influence on diaphragm wall deformation beyond this distance. Additionally, within one excavation depth, the maximum lateral displacement depth tends to be closer to the surface as the distance to the diaphragm wall decreases. Beyond a distance of one excavation depth from the diaphragm wall, the maximum lateral displacement position is approximately at the excavation face. This study significantly contributes to the comprehension of neighboring structures' influence on diaphragm walls during deep excavation, providing crucial insights for enhancing safety measures.