地质力学学报2025，Vol.31Issue(1)：80-90,11.DOI:10.12090/j.issn.1006-6616.2024065
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
摘要
Abstract
[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 integrity assessment and rock wave velocity testing.Therefore,this method requires accurate acquisition of the damage conditions of the rock mass in front of the tunnel face.Various assessment methods can be used for comparison and selection,and a conservative approach can be adopted by using a larger value for the excavation disturbance factor.[Significance]Finally,taking a tunnel in western Sichuan near the Yalahe fault as an example and considering the actual engineering disturbance and fault water pressure,the minimum safety thickness of the rock wall at the tunnel face is calculated to verify the engineering applicability of the proposed method.This research can effectively guide on-site risk prediction and plan formulation;it provides a theoretical basis for the prevention and control of water inrush in tunnels crossing water-rich fault fracture zones.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Key words
fault fracture zone/water inrush disaster/minimum safety thickness/wing crack model/rock mass mechanics/tunnel engineering分类
土木建筑引用本文复制引用
袁东,肖坤..隧道穿越断层破碎带突水机制及岩墙最小安全厚度研究[J].地质力学学报,2025,31(1):80-90,11.基金项目
西藏自治区重点研发计划(XZ202201ZY0021G) （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) （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) This research is financially supported by the Key Research and Development Program of Xizang Autonomous Region(Grant No.XZ202201ZY0021G) （KDNQ213043）
the China Railway Group Limited Technology Research and Development Plan(Grants No.2021-Major-01 and 2022-Major-01)and the Guided Project of China Railway Eryuan Engineering Group Co.,Ltd(Grant No.KDNQ213043). （Grants No.2021-Major-01 and 2022-Major-01）
