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.
FANG Xin
,
LIU Shannan
,
PENG Xiajun
.
Strata Deformation Caused by Construction of Prefabricated Suspended Sinking Shafts in Soft Soil Areas: A Case Study of a Working Shaft of a Connecting Pipe
in Shanghai, China
[J]. Tunnel Construction, 2025
, 45(3)
: 567
-578
.
DOI: 10.3973/j.issn.2096-4498.2025.03.012