Rockburst has a significant effect on the safety and
speed of constructing deepburied tunnels such as the SichuanTibet railway tunnel project using a tunnel boring machine (TBM).
This is a technical difficulty and needs to be resolved. Accordingly, tunnels
with burial depths of over 2 000 m, such as the Hanjiang RiverWeihe River water conveyance project, the ABH project in Xinjiang,
and the Jinping Ⅱ hydropower project, are taken as case
studies. Based on the analysis of mass field data and the characteristics of
the TBM structure and construction method, the following points of
investigation are proposed: (1) the effects of safety and speed and the
spatiotemporal characteristic laws of rockburst on TBM construction; (2)
prevention and control targets of TBM construction corresponding to three
grades of rockburst (slight, medium, and strong); (3) guidelines for rockburst
prevention and control, including advanced speed control, risk control,
spatiotemporal control, and hierarchical control; (4) technical solutions for
the prevention and control of the three grades of rockburst. In this way, a
hierarchical rockburst prevention and control system with coordinated
"equipmentboringsupport"
is established and applied (theoretically and experimentally) to engineering
practices. Results reveal the following: (1) Compared with the TBM boring speed
under no rockburst, the boring speed under slight rockburst is lower by
10%~30%, that under medium rockburst is lower by 30%~50%, and that under strong
rockburst is lower by 50%~75%. (2) Approximately 20%~40% of rockburst phenomena
occur within 10 h after excavation; the highest rockburst frequency is within
10~24 h, with over 90% of rockburst phenomena occurring within 24 h and
approximately 9% of strong rockburst phenomena occurring within 24~48 h. (3)
Over 30% of medium rockburst phenomena occur within the area between the shield
body and tunnel face. Over 90% of medium and strong rockburst phenomena occur
in the area 15 m behind the tunnel face. (4) Approximately 80%~90% of strong
rockburst phenomena can be controlled to occur in the area between the TBM
shield body and tunnel face by controlling the TBM advancing speed. The
proposed technical solutions were successfully applied to the ABH project in
the Xinjiang and Hanjiang RiverWeihe River water
conveyance project, and good effects such as successful passage through the
rockburst section and high TBM construction efficiency were achieved.
DU Lijie
,
HONG Kairong
,
WANG Jiaxing
,
LI Qingwei
,
YANG Yalei
,
LI Weiwei
,
HUANG Junge
.
Rockburst Characteristics and Prevention and Control
Technologies for Tunnel
Boring Machine Construction of Deepburied Tunnels
[J]. Tunnel Construction, 2021
, 41(1)
: 1
-15
.
DOI: 10.3973/j.issn.2096-4498.2021.01.001
