The unfavourable geological conditions of tunnels of
Ya′anNyingchi section of SichuanTibet railway, such as very high stress and soft rock deformation,
rockburst, high ground temperature, active fault, high pressure and water rich
tectonic zone, etc. are systematically expounded in this paper. Based on the research
and analysis of similar tunnel construction experience in China and abroad, the
corresponding treatment principle and engineering countermeasures are put
forward: tunnels in soft rock subject to deformation should be treated by
principle of optimizing tunnel crosssection shape,
active reinforcement, deformation control according to deformation grade, and
strengthening support; tunnel subject to rockburst should be treated by
principle of early warning first, active control, more machines and fewer people,
and ensuring safety; high temperature tunnel should be treated by principle of
strengthening geological prediction, classified prevention and control of heat
damage, comprehensive cooling, reasonable matching materials, and strengthening
labour safety; the overall goal for the active fault section is: the tunnel
will not be damaged by small earthquakes, it can be repaired after moderate
earthquakes, and it will not collapse after large earthquakes, and the
treatment principle are: reserve space, optimize cross section, design by
sections and promote operation monitoring; the highpressure
waterrich tectonic zone should be treated by principle
of longdistance prediction in advance, water discharge
and pressure reduction in advance, water stopping and drainage limitation in
advance, surrounding rock reinforcement in advance, support structure
strengthening and monitoring strengthening.
TIAN Siming
,
WANG Wei
,
TANG Guorong
,
LI Xu
.
Study on Countermeasures for Major Unfavorable
Geological Issues
of Tunnels on SichuanTibet Railway
[J]. Tunnel Construction, 2021
, 41(5)
: 697
-712
.
DOI: 10.3973/j.issn.2096-4498.2021.05.002
