The utilization of offshore composite foundations with
deep cement mixing(DCM) piles in immersed tunnels lacks precedence in China.
Further exploration of the adaptability, stress characteristics, and layout
forms of DCM piles in immersed tunnels is crucial. Therefore, a case study is
conducted on the ShenzhenZhongshan link immersed tunnel. A
threedimensional finite element model is employed to
assess four distinct layout forms of DCM piles. A rational layout form for DCM
piles is indentified and validated through field load plate tests. Key findings
include: (1) DCM piles with shallow cover exhibit subpar quality and low
strength, while the quality of the short pile section under the bracket layout
form cannot be guaranteed. (2) Under similar replacement rates, the simulated
settlement of piles with a singlepile layout is
smaller than that with a bracket layout. Therefore the singlepile layout is superior for DCM piles. (3) The allowable bearing
capacities of the composite foundation, with pile spacings of 3 m × 4 m and 3 m × 3 m, are not less than 158.3
and 211.1 kPa, respectively. These values align well with the calculated
results. (4) Considering the foundation load distribution pattern and load
plate test results, a variable space DCM pile layout of 3~5 m is preferred for
the ShenzhenZhongshan link immersed tunnel.
XU Yu
,
XU Guoping
,
CHEN Weile
,
SONG Shenyou
. Optimal Layout of Deep Cement Mixing Piles for
Composite Foundations in Immersed Tunnels: A Case Study of
ShenzhenZhongshan Link[J]. Tunnel Construction, 2023
, 43(11)
: 1944
-1953
.
DOI: 10.3973/j.issn.2096-4498.2023.11.014
