The method of solving the safety coefficient of an
underground cavern group based on the local strength reduction method is
investigated to accurately evaluate the safety state of large underground
cavern groups. A danger zone is defined as an area with YAI （yield
approach index） of less than 0.1. The danger zone
penetration of the surrounding rock between caverns is used herein as the
criterion for the overall damage of the cavern group. The discount factor
corresponding to the danger zone penetration is defined as the safety factor of
the cavern group damage. The overall stability of the cavern group is
quantitatively evaluated. Moreover, the differences in the calculation results
of the damage criteria of various cavern groups are analyzed. The results show
that: (1)The order of the safety coefficient of each criterion from large to
small is equivalent to plastic strain penetration, plastic zone penetration,
sudden increase in displacement at critical points, and danger zone
penetration. (2)According to the sudden increase in displacement at critical
points, the errors of the safety coefficients of the other three criteria are
33.7%, 13.9%, and 2.6%, respectively.
(3) The calculation result of the safety coefficient based on the danger zone
penetration is closer to that of the displacement surge criterion; moreover,
the damage zone based on the danger zone penetration is consistent with the
actual damage characteristics of the surrounding rock of the project. The
calculation volume is less.
CHEN Yichao
,
ZHANG Liming
,
CONG Yu
,
WANG Xiaoshan
,
WANG Zaiquan
. Damage Criterion of Danger Zone of Underground Cavern
Group Based on Local Strength Reduction Method and Its Engineering Application[J]. Tunnel Construction, 2023
, 43(4)
: 634
-644
.
DOI: 10.3973/j.issn.2096-4498.2023.04.010
