The deformation control is a priority in foundation
pit support design to effectively avoid safety risk of adjacent metro tunnel
caused by excessive deformation of deep foundation pit. The deep foundation pit
slope on the side of the metro tunnel near Chongqing Wuyue Square is taken as
an example, a scheme of grouting reinforcement combined with multipile
stepbystep support is
proposed, in which the structural stress is rational and the deformation
control capacity is strong. The test data of the onsite
grouting test area show that the shear strength and deformation modulus of the
soil after reinforcement have been greatly improved. The displacement and
internal force values of multistage retaining piles
and tunnels under two working conditions with and without grouting
reinforcement are calculated by finite element model. It is concluded that the
soil filling grouting reinforcement can effectively improve the mechanical
properties of the soil before and after the retaining pile, increase the shear strength parameters and
the proportional coefficient of the horizontal resistance coefficient of the
soil, and reduce the internal force of the retaining pile, the length and crosssection size of the pile body. The multistage
platform is set in combination with the building retreat scheme, which
increases the horizontal distance between the slope foot and the slope top, and
reduces the soil pressure value of each step slope. The grouting and multistage platform play a positive role in controlling the support pile
and tunnel deformation, effectively avoid the safety risks caused by excessive
deformation of the foundation pit slope on the metro tunnel and the surrounding
environment.
LI Yangqiu
,
TANG Gengchen
,
LIU Jianning
,
LI Anxing
,
QIU Hong
.
Case Study on Effect of Soil Filling Grouting
Reinforcement on Deep
Foundation Pit Support Structure and Adjacent Tunnels
[J]. Tunnel Construction, 2020
, 40(S2)
: 58
-66
.
DOI: 10.3973/j.issn.2096-4498.2020.S2.008
