隧道穿越断层破碎带突水机制及岩墙最小安全厚度研究  

Water inrush mechanism and the minimum safety thickness of the rock wall of a tunnel crossing a fault fracture zone

作　　者：袁东 肖坤 YUAN Dong;XIAO Kun(College of Water Resource&Hydropower,Sichuan University,Chengdu 610065,Sichuan,China;China Railway Eryuan Engineering Group Company,Ltd.,Chengdu 610031,Sichuan,China)

机构地区：[1]四川大学水利水电学院,四川成都610065 [2]中铁二院工程集团有限责任公司,四川成都610031

出　　处：《地质力学学报》2025年第1期80-90,共11页Journal of Geomechanics

基　　金：西藏自治区重点研发计划(XZ202201ZY0021G);中国中铁股份有限公司科技研究开发计划(2021-重大-01,2022-重大-01);中铁二院工程集团有限责任公司引导项目(KDNQ213043)。

摘　　要：隧道穿越富水断层破碎带时,掌子面前方的隔水岩体在高渗压作用下容易发生水力劈裂破坏,诱发围岩塌方突水等灾害。基于翼裂纹模型,文章从断裂力学角度分析了岩体含水裂纹扩展及岩桥贯通破坏机理,并且重点考虑了隧道开挖扰动导致岩体损伤弱化,提出了临近断层隔水岩体的最小抗劈裂厚度计算方法。通过对不同影响因素的敏感性分析,发现岩体抗劈裂厚度随隧道断面尺寸、断层水压力、开挖扰动因子的增大而增大,随隧道竖向应力和岩体强度的增大而减小;同时开挖扰动损伤对于岩体抗劈裂厚度的计算结果影响最为显著。最后,以临近雅拉河断裂的川西某隧道为例,考虑实际工程扰动和断层水压力因素,计算了现场施工风险防控岩盘厚度,进一步为类似工程提供理论借鉴。[Objective]With the relocation of major national strategic plans to western China,railway construction has gradually focused on the complex and dangerous mountainous regions of Yunnan,Sichuan,and Xizang Provinces,where the proportion of tunnels along the railway is very high.When a tunnel passes through a water-rich fault fracture zone,the rock mass in front of the palm face is prone to hydraulic fracturing and damage under high osmotic pressure,leading to disasters such as rock collapse and water inrush.[Methods]The wing crack model is introduced to fully account for the initiation and propagation of secondary wing cracks in water-saturated fractures,as well as the impact of excavation disturbances.The effective tensile stress and rock bridge size between intermittent fractures in the rock are revised.The tensile-shear failure mechanism of the water-insulating rock mass in front of the tunnel face is analyzed,and the critical water pressure for hydraulic fracturing of the water-insulating rock mass is derived.The minimum safety thickness for the tunnel face against water inrush in the proximity of a fault fracture zone is proposed.[Results]The theoretical formulas indicate that the anti-splitting thickness of the water-insulating rock mass is related to factors such as tunnel section size,fault water pressure,excavation disturbance,in-situ stress,rock mass strength,crack size,and fracture parameters.Through analysis of the sensitivity of the different influencing factors,it is found that the anti-splitting thickness of the rock mass increases with the increase of the tunnel section size,the fault water pressure,and the excavation disturbance factor,but decreases with the increase of the vertical tunnel stress and the rock mass strength.At the same time,the excavation disturbance damage has the most significant impact on the calculated anti-splitting thickness of the rock mass.[Conclusion]In practical engineering,there are certain empirical judgments and errors in obtaining excavation disturbance factors via rock

关 键 词：断层破碎带 突涌灾害 最小安全厚度 翼裂纹模型 岩体力学 隧道工程 

分 类 号：TU452[建筑科学—岩土工程] U25[建筑科学—土工工程]