Evaluating the Effects of Deep Excavation on Nearby Structures Through Numerical Simulation

Traditional numerical analyses often overlook the potential impact of adjacent building basements on ground surface deformation. This study investigated the influence of neighboring structures on diaphragm walls and ground surface deformation during deep excavation for building foundations using PLAXIS 3D finite element software. This study simulated the top-down construction method with plate elements for diaphragm walls retaining H-shaped steel for support and pre-stressed anchors. The adjacent structures were modeled using plate elements. Numerical analysis results were compared with field observations for model validation. The results show that the lateral displacement of the retaining wall varies with the depth of neighboring basements. At 0.5 times the excavation depth, displacement was significant, and it stabilized at 1.0 times the depth. When the distance between adjacent buildings and the retaining wall was about twice the excavation depth, the deformation curve converged, indicating negligible influence beyond this distance. Ground surface settlement increased as the neighboring basement depth reached half the excavation depth, and stabilized at 1.6 times the depth. A closer proximity resulted in greater ground surface settlement. These findings offer practical references for deep excavation design and assessment, aiding engineers in ensuring project stability and safety.