穿越富水断层破碎带隧道塌方机理分析与预防  

MECHANISM AND PREVENTION OF TUNNEL COLLAPSE THROUGH WATER-RICH FAULT FRACTURE ZONE

作　　者：杨建辉 沈恺 周杰[2,3] 薛亚东 YANG Jianhui;SHEN Kai;ZHOU Jie;XUE Yadong(School of Civil Engineering and Architecture,Zhejiang University of Science and Technology,Hangzhou 310023,China;Key Laboratory of Geotechnical and Underground Engineering of the Ministry of Education,Tongji University,Shanghai 200092,China;Department of Geotechnical Engineering College of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]浙江科技学院土木与建筑工程学院,中国杭州310023 [2]同济大学岩土及地下工程教育部重点实验室,中国上海200092 [3]同济大学地下建筑与工程系,中国上海200092

出　　处：《工程地质学报》2023年第1期248-257,共10页Journal of Engineering Geology

基　　金：浙江省自然科学基金(资助号:LHY19E090001)。

摘　　要：穿越山岭隧道常遇到断层破碎带。由于缺乏断层复杂岩体稳定性机理的研究与理解,隧道施工曾导致多起大变形甚至塌方事故。本文使用理论分析、离散元数值模拟方法,结合现场监测结果,对江西某高速铁路隧道过断层施工案例进行综合分析。在考虑断层破碎带地下水影响的前提下,开展富水断层破碎带施工过程中围岩失稳塌方的内在机理研究。研究得出:隧道穿越富水断层破碎带时,岩体结构面发育,且结构面间多充填碎屑或黏土充填物。随着施工扰动引发结构面发生错动,流动的地下水进一步对结构面形成冲刷,从而降低围岩的完整性与力学强度。断层破碎带抗剪强度越低,围岩松动范围越大,塌方概率与范围越大。根据“防水排水,强化围岩”的思路,本文提出了穿越断层破碎带防塌方的措施:设置迂回导坑、地层预加固、增加支护强度、优化施工工法及加强监控量测,可为此类隧道工程的安全施工提供参考。Tunnels across mountain always go through fracture zones. With lack of knowledge of the mechanisms on rock faults, constructions on rock tunnels used to bring about quite an amount of collapse accidents with large deformations. This paper applied a combination of theoretical and numerical simulation with the on-site monitoring data. It considered the underground water in rock faults and examined the surrounded rock instability and collapse mechanism during the construction process. The result shows that the discontinuous structural plane is fully infilled with debris or clay when the tunnels going through water-rich fracture zones. Coupled with construction disturbances, the structural surfaces are prone to dislocation, causing groundwater flow with further damages. The formation of structural surface erosion reduces the integrity and mechanical strength of the surrounding rock. The lowers the shear strength of the fault fracture zone, the larger the range of loosening of the surrounding rock and the greater the probability and range of collapse. Based on the principle of “water resisting, drainage and strengthening surrounding rock”,this paper proposes several measures letting tunnels go through fracture zones preventing collapse. These strategies can provide references for maintaining construction safety in upcoming project and include setting up detour pits, pre-reinforcement of the ground, increasing support strength, optimizing construction methods and strengthening monitoring measurement.

关 键 词：铁路隧道 塌方 离散元 机理分析 断层破碎带 

分 类 号：U45[建筑科学—桥梁与隧道工程]