The traditional temporary invert constructed by Isteel
+ shotcrete is complex in the construction process. Moreover, its construction
quality is greatly affected by human factors and cannot be reused. Therefore, a
novel detachable concretefilled steel tube temporary
invert and its supporting structure, designed for easy and rapid disassembly,
are proposed. The structures are tested and applied to the highspeed Zongka #2 tunnel of the TongrenSai′erlong railway. The steel pipe has an outer
diameter of 108 mm and a wall thickness of 8 mm, and is filled with C30 fine
stone concrete. The detachable components comprise a sleeve and a builtin wedgeshaped unloading block, and the concretefilled steel tubes are inserted from both sides to achieve segment
connection. Field application results reveal the following: (1) The proposed
temporary invert structure is safe, reliable, and feasible and can realize
factory prefabrication and quick disassembly on site. The proposed temporary
invert can improve construction efficiency by 643% and
reduce the settlement deformation rate of the arch and peripheral convergence
rate by 657%~661% and 746%~795%, respectively, compared to the
traditional temporary invert constructed by I-steel + shotcrete. (2) The axial
force value measured during the operation of the structure is less than the
calculated and designed ones, indicating that the structure is in a safe state.
The reutilization rates of the segment and detachable structure are up to 94.5%
and 100%, respectively.
CHEN Shihao
,
DAI Qinghua
,
CHEN Peishuai
,
YUAN Qing
,
XIONG Qihuan
,
YANG Zhao
. Technology and Application of Temporary Invert With
Detachable Components in Tunnels[J]. Tunnel Construction, 2023
, 43(10)
: 1779
-1787
.
DOI: 10.3973/j.issn.2096-4498.2023.10.014
