基于离散元方法的千枚岩隧道掌子面稳定性研究  

Study of phyllite tunnel face stability based on discrete element method

作　　者：王启志 张立舟 朱海明[1,2,3] 周成涛 陈林[1,2,3] WANG Qizhi;ZHANG Lizhou;ZHU Haiming;ZHOU Chengtao;CHEN Lin(Chongqing Institute of Surveying and Mapping Science and Technology,Chongqing 401121,China;Chongqing Survey Institute,Chongqing 401121,China;Technology Innovation Center for Spatiotemporal Information and Equipment of Intelligent City,Ministry of Natural Resources,Chongqing 401121,China)

机构地区：[1]重庆市测绘科学技术研究院,重庆401121 [2]重庆市勘测院,重庆401121 [3]自然资源部智能城市时空信息与装备工程技术创新中心,重庆401121

出　　处：《现代城市轨道交通》2024年第7期65-71,共7页Modern Urban Transit

基　　金：重庆市建设科技计划项目(城科字2022第1-12号);重庆市技术创新与应用发展专项面上项目(CSTB2022TIAD-GPX0046);重庆市自然科学基金项目(cstc2021jcyj-msxm3174)。

摘　　要：千枚岩隧道在施工过程中由于围岩软弱破碎,易在掌子面附近发生失稳塌方。文章采用颗粒流软件PFC模拟炭质千枚岩三轴试验,标定围岩材料的细观参数,以此构建隧址区三维离散元数值计算模型,模拟隧道在不同开挖进尺和开挖方法下开挖支护全过程,分析隧道开挖后掌子面位移发展规律和开挖扰动区分布范围特征,揭示千枚岩隧道掌子面失稳机理。数值计算结果表明:随开挖进尺的增大,隧道开挖扰动区范围增大;在不同开挖方法中,台阶法的开挖扰动区范围最小。相关研究可为类似软弱破碎围岩隧道的设计和施工提供参考。During the construction of phyllite tunnel,due to the weak and broken surrounding rock,instability and collapse often occur near the tunnel face.In this paper the discrete element software PFC is used to simulate the triaxial test of carbonaceous phyllite,and the mesoscopic parameters of surrounding rock materials are figured out,so as to establish a three-dimensional discrete element numerical calculation model of tunnel site area,and to simulate the whole process of excavation and support under different excavation footage and excavation methods.The development principles of tunnel face displacement and the distribution range of excavation disturbance area after tunnel excavation are analyzed,and the instability mechanism of tunnel face in phyllite tunnel is revealed.The numerical calculation results show that:with the increase of excavation footage,the range of tunnel excavation disturbance area increases;among the different excavation methods,the excavation disturbance area of the step method is the smallest.The relevant research could provide reference for the design and construction of similar tunnels with weak and fragmented surrounding rocks.

关 键 词：千枚岩隧道 掌子面稳定性 离散元方法 PFC 缩尺模型 

分 类 号：U455.5[建筑科学—桥梁与隧道工程]