基于Winkler地基模型的岩质隧道软弱底板塑性区研究  

Study on the Plastic Zone of Weak Floor in Rock Tunnel by Winkler Foundation Model

作　　者：于远祥[1] 王兵强 

机构地区：[1]西安科技大学建筑与土木工程学院,陕西西安710054 [2]中煤科工集团西安研究院,陕西西安710077

出　　处：《中国公路学报》2015年第9期82-90,共9页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51204113);陕西省自然科学基础研究计划项目(2014JM2-5052);西安科技大学博士启动资金项目(2014QDJ049)

摘　　要：为了给侧墙及底板的支护设计及施工提供参考,根据隧道侧墙岩层及其受力特点,将侧墙视为一半无限承载梁,其软弱底板岩体简化为连续的弹性地基,建立了隧道侧墙在支承压力作用下的Winkler弹性地基梁模型,分析了侧墙任一界面上挠度、转角、弯矩及剪力的分布规律,推导了侧墙极限平衡区宽度与隧道埋深、底板岩体的弹性特征值、上覆岩层重度及侧墙应力集中系数、弹性区宽度、弹塑性界面上岩体抗剪强度的关系式。在确定侧墙极限平衡区宽度的基础上,探讨了隧道软弱底板在其侧墙挤压下产生的最大塑性区破坏深度。结果表明:底板最大塑性区破坏深度与隧道埋深、侧墙应力集中系数及其极限平衡区宽度、上覆岩层及底板重度、底板黏聚力及内摩擦角等参数密切相关。To provide reference for design and construction of sidewall and floor, sidewall was regarded as a half infinite load-bearing beam and its soft and weak floor rock mass was simplified to a continuous elastic foundation, according to sidewall stratum and its mechanical characteristics of the tunnel. By setting up Winkler elastic foundation beam model of the sidewall under high bearing pressure, the distribution law of deflection, rotation, bending moment and shear force of sidewall on any interface of rock mass was analyzed and the relations between the limit equilibrium zone width and tunnel buried depth, the elastic characteristic value of floor rock, overburden rock mass density as well as stress concentration factor, elastic zone width and the shear strength of rock mass on elastic-plastic interface of the sidewall were derived. The maximum plastic failure depth of the weak floor under the squeeze of sidewall was discussed after the limit equilibrium zone width was certain. The result shows that the maximum plastic failure depth is closely related to the tunnel buried depth, stress concentration factor, the limit equilibrium zone width of the tunnel wall, the volume-weight of overburden rock mass and floor, the cohesion and internal friction angle of the floor.

关 键 词：隧道工程 岩质隧道 理论分析 软弱底板 支承压力 WINKLER地基 塑性区深度 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]