Currently,
there are problems such as lack of onsite monitoring data and
single research method in giantspan flat caverns,
which cause difficulties in analyzing the deformation characteristics and
stability of caverns. Here, a case study is conducted on a giantspan cavern with horizontal stress as the main stress. Additionally,
based on the geological conditions, insitu stress, and excavation sequence of
the cavern, the settlement characteristics of a giantspan
cavern arch are analyzed using onsite monitoring data
analysis and threedimensional numerical calculations.
The results reveal the following: (1) The overall settlement of the giantspan cavern is relatively small, with a maximum value of 22.8 mm, it
is affected by geological conditions, ground stress, and structure, and its
deformation has a certain degree of discreteness. (2) The dismantling sequence
of the rock pillar in the giantspan cavern accounts
for 40%~60% of the total settlement. (3) The deformation curve of the giantspan cavern during the excavation process presents the
characteristics of a combination of step and zigzag, and its stabilization
mechanism is a combination of the overall stability of stress control and the
local stability of the structural plane control. (4) The excavation disturbance
range of the vault of the giantspan cavern mainly
exists in the shallow rock mass around the cavern, and the excavation disturbance
range near the spandrel mainly exists in the shallow and middle rock mass
around the cavern, and the excavation has a weak influence on the deep rock
mass.
SONG Chaoye
,
LYU Shuqing
,
HE Weiguo
,
HONG Kairong
,
LIU Yongsheng
,
WANG Xing
.
Analysis of Arch Settlement Characteristics of Giant-Span Flat
Cavern in Construction Period
[J]. Tunnel Construction, 2022
, 42(10)
: 1712
-1719
.
DOI: 10.3973/j.issn.2096-4498.2022.10.005
