The theoretical
calculation, field monitoring, and numerical simulation analysis are employed
to examine the load characteristics of the surrounding rock and segments of a
super-large diameter shield tunnel on
Chunfeng road. Typical sections of the Chunfeng road tunnel are selected to
conduct a comparative analysis of the theoretical calculation values of full-soil cover and the measured pressure data of surrounding rock. The
mechanical behavior characteristics of the segment structure, steel bars, and
bolts are obtained through field monitoring, and a three-dimensional numerical model of the segment including actual
reinforcement is established for comparison and verification with the measured
values. The following conclusions are obtained: (1) The surrounding rock
pressure measured by the earth pressure gauge in the sandstone formation is in
good agreement with the calculated value of the full-soil
cover theory without considering the water pressure. (2) The measured load on
the off-load side of a section increases by 50%
relative to the calculated value, and the calculation of surrounding rock load
should consider the off-load effect of additional load
for local amplification. (3) The monitoring data analysis shows that the
mechanical safety redundancy of the segments and rebar is relatively high,
which does not exceed 40% of the design strength value. (4) The structural stress
values obtained by modeling are in good agreement with the measured values. (5)
Without considering the difference of artificial installation, the axial force
distribution of bolts between blocks is relatively uniform.
SUN Zhenchuan
,
LYU Qianqian
,
SUN Feixiang
,
YANG Zhenxing
.
Surrounding Rock Load and Segment Mechanical Behavior of Chunfeng Road Super-Large Diameter Shield Tunnel
[J]. Tunnel Construction, 2024
, 44(S2)
: 84
-92
.
DOI: 10.3973/j.issn.2096-4498.2024.S2.008
