To further investigate the convergence deformation
mode of soft rock tunnel section in mountainous area, a case study is conducted
on the crown settlement and horizontal convergence of arch waist of a tunnel
section, the ratio 〖WT５《TNR#I》〗K〖WT５《TNR》〗 of crown settlement and horizontal convergence of arch waist is
proposed based on the existing uneven convergence mode of metro shield tunnel,
so as to parameterize the deformation of tunnel crosssection.
Additionally, three forms of convergence deformation of tunnel crosssection are proposed based on 〖WT５《TNR#I》〗K〖WT５《TNR》〗 value. Finally, the monitoring data of
tunnel crosssection deformation under different buried
depths in Gansu section of the Ganqing tunnel on XiningChengdu highspeed railway are analyzed. The results show the
following: (1) The parametric analysis of the 〖WT５《TNR#I》〗K〖WT５《TNR》〗 value shows that the deformation mode
of the tunnel crosssection is mainly affected by the
tunnel uniform convergence 〖WT５《TNR#I》〗〖ＱＸ（Ｙ８〗ε〖ＱＸ）〗〖WT５《TNR》〗 and the tunnel ovalization 〖WT５《TNR#I》〗〖ＱＸ（Ｙ１０〗δ〖ＱＸ）〗〖WT５《TNR》〗. (2) The
buried depth of the tunnel has a certain influence on the convergence deformation
of the tunnel crosssection after tunnel excavation.
Because the surrounding rock of the tunnel is relatively stable under the
condition of deep buried depth, the convergence deformation of the tunnel crosssection is small and tends to be stable in a short time. (3) The
uneven convergence model and the existing empirical parameters are suitable for
the tunnel crosssection in the shallow buried area
(buried depth of 17.8~19.3 m), but the applicability of the tunnel crosssection in the deep buried area (buried depth of 48.5~49.3 m) is not
good. (4) For the first time, the uneven convergence mode of the tunnel crosssection from the metro shield is introduced into the mountain
tunnel. Due to the complexity of the mountain tunnel construction, the current
research on the 〖WT５《TNR#I》〗K〖WT５《TNR》〗 value of the mountain tunnel is only a preliminary applicability
study, which needs further study.
LIU Xu, WU Honggang, GUAN Wei, SUN Hao
.
Applicability of Uneven Convergence Mode in Soft Rock
Tunnels
[J]. Tunnel Construction, 2023
, 43(S1)
: 240
-247
.
DOI: 10.3973/j.issn.2096-4498.2023.S1.028
