A significant
length, large buried depth, and high stresses in the surrounding geological
strata of a plateau railway tunnel may induce rockburst and large deformations
in weak rocks in high groundstress areas. In this paper, the
major challenges associated with rockburst, deformation, and collapse
prevention for a tunnel boring machine(TBM) are comprehensively analyzed using
comparisons with previous projects, practical construction experience, and
technical analyses. Suitable countermeasures are proposed. Generally, the full
understanding of the construction project characteristics, TBMtargeted design, and TBM technical innovations are the key
considerations. These include the following: (1) TBMtargeted
design includes a suitable cutterhead expansion and shield length, shield
strength enhancement, shield protection range enlargement, and advance support
and emergency support strengthening. (2) Adopting hierarchic, active, and
passive prevention and control methods for rockburst in high groundstress areas. (3) Focusing stress resistance and release on areas
with soft rock strata with high ground stress and providing continuous and
rapid excavation and timely support. (4) Emphasizing stable excavation, advance
reinforcement, timely support, and backfill grouting in deeply buried broken
strata.
DU Chuangdong
,
HONG Kairong
,
LI Zhijun
,
YANG Yandong
. Key Technologies of Tunnel Boring Machine Passing
through Unfavorable Geology： a
Case Study of Entrance Section of a Plateau Railway Tunnel[J]. Tunnel Construction, 2022
, 42(7)
: 1274
-1288
.
DOI: 10.3973/j.issn.2096-4498.2022.07.016
