Abstract: The authors conduct a case study on the Zhuyuan Bailonggang sewage connecting pipe project in Shanghai, China, to examine the deformation patterns of the surrounding strata induced by the construction of a prefabricated suspended sinking shaft under complex environmental conditions. They also examine how varying construction parameters influence strata deformation. Additionally, a three-dimensional finite element model is established to simulate the shaft sinking process, enabling a systematic analysis of its effects on strata deformation. Furthermore, parameter sensitivity analysis is employed to determine the sensitivity of maximum soil deformation to various construction parameters. The results reveal the following: (1) The maximum surface settlement in soft soils induced by the construction of prefabricated suspended sinking shafts in soft soils is significantly smaller than that associated with the traditional press-in caisson method. The settlement remains well within the allowable limits for foundation pits under Shanghai′s first-class environmental protection standard. This demonstrates the suitability of this method for shaft engineering in soft soil areas with stringent requirements for stratum deformation control. (2) The surface settlement pattern transitions from a triangle to a groove shape with increasing sinking depth. The maximum horizontal displacement in the deep soil primarily occurs within weak soil layers. (3) Under the shaft diameter conditions of this project, the influence range of surface settlement is approximately 1.0H－1.4H (H refers to excavation depth). This range is considerably smaller than that typically observed in foundation pit projects in soft soil areas. (4) Among the construction parameters, the slurry level and slurry unit weight exert the most significant influence on soil deformation. For large-diameter shafts, the slurry unit weight should be rigidly controlled. Meanwhile, the slurry level can be raised to minimize the influence on the deformation of the surrounding strata.

Key words: prefabricated suspended sinking shaft construction method, numerical analysis, sensitivity analysis, soil deformation