Abstract: In order to solve the problems of initial support deformation, inverted arch uplift,
secondary lining collapse and other problems during the construction of high ground stress soft
rock tunnel, the key technology research of large deformation control is carried out relying on
Daliangshan Tunnel of Yunlin Expressway. The large deformation section of the tunnel has a large
cumulative deformation amount, high deformation rate, and long duration of initial support
deformation. The inverted arch has a long disease section with large elevation difference and is
greatly affected by water; The deformation patterns and failure characteristics of the second lining
are as follows: crushing failure, failure location at the arch shoulder and arch crown, sudden
failure at the time, and delayed pouring of the second lining for several months. Through a
comprehensive analysis of the geological conditions, failure characteristics, deformation
characteristics, and supplementary survey conclusions of the soft rock large deformation section of
网络首发时间：2023-11-08 12:44:41
网络首发地址：https://link.cnki.net/urlid/44.1745.U.20231107.1430.003
the Daliangshan Tunnel, theoretical analysis, engineering analogy, numerical simulation, and
on-site measurement are used to propose a design plan for large deformation treatment, including
optimization of inverted arch curvature, initial support of double layer steel frame, secondary
lining reinforcement of lining, and limiting anchor bolts around the tunnel. After that, construction
and research on the experimental section are carried out. The experimental results show that: 1)
The cumulative construction of the experimental section is 323m, with an average monthly
footage of about 43m/month; 2) Co MPared with the original design, the support scheme for the
experimental section has reduced the maximum peripheral convergence value of the initial support
from 1.4m to 0.30m, the maximum arch settlement value from 0.80m to 0.52m, and the daily
average deformation amount from 7cm/d to 1-2cm/d; 3) The large deformation of the tunnel has
been effectively controlled, with no cracking or falling of the initial support, and no damage to the
inverted arch and secondary lining; 4) Based on monitoring data and on-site conditions, the
comprehensive support system scheme for the experimental section is analyzed and summarized
to be reasonable, and the key technologies for large deformation treatment are generally
successful.

Key words: Tunnel engineering, High geostress, Soft rock, Large deformation, Support system