ISSN 2096-4498
CN 44-1745/U
ISSN 2096-4498
CN 44-1745/U
Fault and Fracture Zone Collapse Treatment Technology for Open Tunnel Boring Machine Applied in Beijiang Water Diversion Project
(1. China Railway 18th Bureau Group Tunnel Engineering Co., Ltd., Chongqing 400700, China; 2. China Railway 18th Bureau Group Co., Ltd., Tianjin 300222, China; 3. School of Civil Engineering, Central South University, Changsha 410075, Hunan, China; 4. School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, Sichuan, China; 5. School of Civil Engineering, Tianjin University, Tianjin 300072, China; 6. Tunnel and Underground Engineering Research Center of Central South University, Changsha 410075, Hunan, China; 7. Hunan Provincial Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering Structures, Central South University, Changsha 410075, Hunan, China)
Online published: 2024-01-04
Implementing the innovative "host shield+spray anchor support" open tunnel boring machine(TBM) in Guangzhou′s #4 tunnel for the Beijing water diversion project resulted in the collapse of fault and fracture zones. Consequently, considering the collapse characteristics and open TBM, a targeted treatment plan is proposed. This plan involves chemical grouting to fill collapsed cavities, reinforcing loose bodies, spray anchor support, dense arch support, and advance grouting reinforcement. A finite element numerical simulation model is established based on onsite conditions to assess the plan′s feasibility. The simulation results are: (1) The fault center experiences a maximum vertical displacement of approximately 2.1 mm, with a relative convergence displacement of the arch foot of 0.05%. (2) Shotcrete′s maximum tensile stress is approximately 1.0 MPa, and the bolt at the crown has a maximum tensile stress of 41.6 kN, which meets the stress and deformation control requirements. The applied chemical grouting effectively prevents further largescale collapses of the support structure. Reinforcement grouting successfully cements loose bodies, forming a 3 mthick bearing ring and preventing continuous collapse of the stone slag. After treatment, the primary support is substantially enhanced. The surrounding rocks not yet detached from the shield tail are pregrouted and reinforced, ensuring successful TBM passage through the fault and fracture zone. The measured maximum vertical displacement of the arch crown is approximately 2.0 mm, with a relative convergence displacement of approximately 0.10%, ensuring construction safety in the open section behind the TBM shield tail.This approach guarantees structural integrity and safety in challenging fault and fracture zones.
CHEN Songlin
,
WANG Lichuan
,
HU Hengqian
,
WANG Shuying
,
YANG Zebin
,
CHONG Panpan
,
LU Chuang
,
CHEN Hongwei
.
Fault and Fracture Zone Collapse Treatment Technology
for Open Tunnel Boring Machine
Applied in Beijiang Water Diversion Project
/
| 〈 |
|
〉 |