Analysis of deformation characteristics for deep excavation groups considering spatiotemporal effects

The construction of deep excavations is characterized by significant spatiotemporal effects. Reasonable zoned excavation can effectively reduce deformation caused by deep excavation construction, thereby minimizing impacts on the surrounding environment. This study focuses on a group of deep excavation projects adjacent to subway tunnels. Numerical simulation methods were employed to analyze deformation characteristics during zoned excavation, with comparisons made to large-area excavation approaches. Research findings indicate that the deformation characteristics of the retaining structures in deep excavation groups are closely related to both the construction procedures and the locations of monitoring points. Under both full-area excavation and zoned excavation methods, the deformation trends of the deep excavation retaining structure remain largely consistent. Compared with full-area excavation, zoned excavation reduces the horizontal displacement of the diaphragm wall adjacent to the tunnel side by approximately 9.94%, decreases the horizontal displacement of the diaphragm wall on the side away from the tunnel by 6.68%, and reduces the horizontal displacement of the middle partition wall by 8.28%.