Cavern stabilizing mechanism, key geological
parameters and their corresponding evaluation system, quantitative design
method, construction techniques, and monitoring methods of a giantspan
flat underground cavern are analyzed through literature investigation,
theoretical analysis, and application verification. Conclusions drawn from the
study are as follows: (1) A timely and active support system, which can warm up
and recover the bearing capacity of surrounding rocks, is key to a giantspan flat underground cavern construction. (2) The size effect must
be considered in the surrounding rock stability evaluation system of a giantspan flat underground cavern. The structural surface occurrence,
geostress, span, heightspan ratio, and friction angle
are also equally important for the cavern. (3) Spraying + anchoring + a
flexible support system is feasible, and it is recommended to adopt a
comprehensive design method combining numerical calculation, construction
experience of similar projects, and monitoring measurement. (4) Reserved doublerock column support method is rational. (5) The stress and
displacement fields of surrounding rocks and structures should be monitored
using various methods. A comprehensive identification method that regards the
convergence and settlements as key indices while considering internal
surrounding rock displacement is proposed to evaluate the stability of
surrounding rocks and structures during the construction and operation phases
of giantspan flat underground caverns.
LIU Yongsheng
,
HONG Kairong
,
ZHUO Yue
,
YANG Chaoshuai
,
SONG Chaoye
,
LIU Longwei
. Construction Techniques and Application of GiantSpan
Flat Underground Caverns[J]. Tunnel Construction, 2022
, 42(4)
: 532
-539
.
DOI: 10.3973/j.issn.2096-4498.2022.04.002
