To address the large
deformation encountered during the construction of the Haba Snow Mountain
tunnel on the Lijiang-Shangri-La section of the Yunnan-Xizang railway, the
authors employ numerical simulations and on-site
monitoring methods to examine the deformation of the tunnel and the stress in
the main tunnel area under different advance distances of parallel guiding
tunnels. A reasonable advance distance for the parallel guiding tunnels is
proposed. The research results indicate the following: (1) The advance distance
of the parallel guiding tunnel should be 100 m ahead of the main tunnel, which
can achieve a stress release effect of over 90% on main tunnel area by parallel
guiding tunnel. (2) On-site monitoring results show
that the parallel guiding tunnel reduces the settlement of the main tunnel
crown by 6.92%, the horizontal convergence of the upper bench by 14.58%, and
the horizontal convergence of the lower bench by 10.8%. Thus, it is evident
that the advance excavation of the parallel guiding tunnel can reduce the
deformation of the main tunnel support. The control effect on the horizontal
convergence of the main tunnel is greater than that on the crown settlement.
TAN Zhongsheng, ZHANG Baojin, MA Jianhua, CHEN Yingwu, ZHAO Jinpeng, FAN Xiaomin, WANG Xuebing
. Reasonable Advance Distance
of Parallel Guiding Tunnels
in Super-Deep Soft Rock Tunnels[J]. Tunnel Construction, 2024
, 44(S1)
: 1
-7
.
DOI: 10.3973/j.issn.2096-4498.2024.S1.001
