Abstract: The evaluation of the deep excavation coupled influence zone is critical to the deep excavation supporting structure design and the protection of the adjacent buildings and utilities. This paper presents a case history of evaluation a slurry wall as the deep excavation supporting structure. The slurry wall system was simulated by the plane strain finite element model with modified CamClay soil constitutive model. The measured vertical and horizontal deflections in a single deep excavation pit were compared with the numerical analysis results. The required slurry wall dimensions at different spacing between two deep excavation pits, different excavation depths in each pit are investigated. Throughout the parametric studies on the spacing and depth of two adjacent deep excavations, the coupled influence zone was thoroughly evaluated. The results indicated that, the soil constitutive model and other soils parameters used in the analysis are appropriate. The influence of the adjacent deep excavation reduces with the increase spacing between two excavations. The horizontal influence zone can be characterized as ten times of the excavation depth.

Key words: adjacent areas, deep excavations, soft soil area, large deep excavations with great depth, lateral deflection of slurry wall, ground subsidence