Mechanical Mechanism of Hydraulic Fracturing Effect Caused by Water Inrush in Tunnel Excavation by Blasting

Table 1

Typical tunnel water inrush accidents with hydraulic fracturing effect [18].

Number	Location	Bad geology	Water source	Outlet position	Water inrush characteristics
1	Bagualing Tunnel DK132 + 340	A large cave on the left arch	Karst water	Advanced geological exploration	Water inflow was 15,000 m^3/h
2	Yuanliangshan Tunnel DK354 + 879	Cave in front	High-pressure karst water	Face	Peak water inrush volume was 3000 m^3/h
3	Yuanliangshan Tunnel DK361 + 764	A karst pipeline on the right side and developed bedding cracks	Karst water head is about 200 m	Karst pipeline	Maximum water inflow was 216 m^3/min
4	Bieyancao Tunnel DK406 + 422	The junction of soluble rock and nonsoluble rock	High-pressure karst water	Rock blast hole	The initial water pressure was over 1.0 MPa
5	Bieyancao Tunnel DK406 + 680 ∼+ 710	Fault zone, a dark river on the right	Karst water	Right wall	Peak water inflow was 2100 m^3/h
6	Pishuangao Tunnel RK63 + 094∼+102	Developed karst	Karst water	Construction joints at the bottom of the tunnel	Gushing
7	Yesanguan Tunnel DK124 + 602	Fault fracture zone	Karst water	Face	Water inflow in the first 30 minutes was 151,000 m^3
8	Wuzhishan Tunnel K29 + 543	Fault fracture zone	Karst water	Face	Peak water inflow was 16,000 m^3/d