裂纹对直墙拱形隧道围岩损伤破坏模式的影响规律研究  

Influence of cracks on surrounding rock damage-failure mode of straight wall arch tunnel

作　　者：周磊 朱哲明 刘邦 

机构地区：[1]四川大学建筑与环境学院能源工程安全与灾害力学教育部重点实验室,四川成都610065

出　　处：《岩土力学》2017年第12期3688-3697,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.11672194;No.11702181);四川省安全监管局安全生产科技项目(No.aj20170515161307)~~

摘　　要：运用不同的有限元分析软件(RFPA^(2D)、ABAQUS)模拟研究隧道周边裂纹对直墙拱形隧道围岩稳定性的影响。裂纹分布在隧道拱底、边墙、拱肩、拱顶等部位,将两种数值模拟方法进行对比分析,研究隧道周边裂纹的起裂、扩展机制及隧道围岩在围压载荷作用下的破坏形式。为了验证数值模拟结果,采用水泥砂浆制作隧道模型进行模型试验并与数值模拟结果进行对比分析,其数值分析与模型试验结果较为一致。结果表明,隧道墙脚处的裂纹是隧道围岩破坏的较弱位置;隧道拱顶圆弧位置处的裂纹与隧道拱顶圆弧圆心成45°夹角时,隧道模型的抗压强度最低,稳定性最差;隧道在围压作用下,破坏形式主要是拱底、拱顶的拉伸破坏和边墙、裂纹尖端的压剪破坏。The effect of cracks on the stability of surrounding rock of the straight wall arched tunnel was simulated by using different types of finite element analysis software（RFPA^（2D） and ABAQUS）. Cracks were normally distributed in the arch bottom, sidewall, arch shoulder, roof and other parts of the tunnel. This study investigated the mechanisms of crack initiation and propagation and the damage-failure patterns of surrounding rock under the confining pressure. The detailed comparisons and discussions of these two finite element methods（FEM） were presented. The model tests using cement mortar were conducted to validate the results obtained by numerical simulations. There was a good agreement between experimental results and numerical simulations. The results showed that cracks at the corner were the weak position of surrounding rock in the tunnel. When the crack at the arc of the tunnel roof formed 45° angle with the arc centre of the tunnel roof, the compressive strength of the tunnel was the lowest and the stability was the worst. Under the confining pressure, tensile failure mainly occurred at the arch bottom and the roof, and shear failure was observed at the sidewall and the crack tip.

关 键 词：裂纹 数值模拟 岩石破裂过程分析 隧道 

分 类 号：TU45[建筑科学—岩土工程]