A case study is conducted on the Songhu roadSanmen
road underpass project to control the surface settlement and deformation of
adjacent structures while constructing a largesection
rectangular pipe jacking tunnel with shallow overburden in the urban core area.
Moreover, the metro jet system(MJS) method is used to reinforce the adjacent
existing box culvert structure, a new pressure selfcompensating
and locking pipe joint antireaction system is designed
and developed, the pipe jacking construction parameters are scientifically and
rationally set, and a novel frictionreducing
thixotropic slurry and injection technology are developed, realizing
microdisturbance on the surrounding environment caused by the construction of a
largesection rectangular pipe jacking tunnel with
small spacing. The results are as follows: (1) The MJS reinforcement technology
protects the existing structure crossed by the pipe jacking. (2) The
antireaction of the pipe joint controls the average cumulative retreat
deformation of the pipe joint within 20 mm. (3) The primary parameters during
the propulsion process are regulated within a predetermined range. (4) The
frictionreducing thixotropic slurry effectively fills
the building gap and reduces friction. According to the fieldmeasured deformation data, the cumulative surface settlement is
controlled between 〖WT5BZ〗-〖WT５《TNR》〗19.74 and
6.92 mm, the settlement of the surrounding soil around the box culvert
structure above the pipe jacking is controlled between 〖WT5BZ〗-〖WT５《TNR》〗3.67 and 3.01
mm, andthe vertical displacement of the structure is
controlled between 〖WT5BZ〗-〖WT５《TNR》〗4.54 and
4.26 mm, indicating a good construction effect.
LIU Xidong
. Microdisturbance Construction Control Technology for SmallSpacing Rectangle Jacking Tunnels with Large Section: A Case Study of Songhu RoadSanmen Road
Underpass Project[J]. Tunnel Construction, 2023
, 43(9)
: 1590
-1604
.
DOI: 10.3973/j.issn.2096-4498.2023.09.017
