For deep and large pits composed of different shapes,
the excavation sequence significantly influences the deformation of the
foundation pit and its supporting structures. To minimize the impact of
different excavation sequences on construction stability and determine the
optimal sequence, numerical simulations are conducted using finite element
software based on the Fuzhou Metro Foochow Arsenal Station excavation project.
Circular and rectangular sections are considered, and various excavation
sequences are simulated. The following conclusions are drawn: (1) For smallspan
pits, excavating the rectangular section first and then the circular section
results in larger surface settlements compared to excavating the circular
section first, whereas for circular and largespan
pits, excavating the rectangular section first and then the circular section is
more favorable. (2) Excavating the rectangular section first and then the
circular section leads to smaller maximum horizontal displacements of the
sidewalls compared to the reverse sequence. (3) For the circular section, cut
and cover excavation is superior to open cut excavation, and preserving the
core soil during excavation is the optimal method. In summary, excavating the
rectangular section first and then the circular section, with the circular section
excavated using cut and cover excavation while preserving the core soil,
represents the optimal approach.
LIU Rui, FANG Chengcheng, CHU Zhumin, LI Meng
. Optimisation of Zoned Excavation Sequence of Deep and
Large Foundation Pit in Urban Metro Station[J]. Tunnel Construction, 2023
, 43(S2)
: 513
-522
.
DOI: 10.3973/j.issn.2096-4498.2023.S2.056