预应力锚杆对岩体板裂化的控制机制研究  

Study of controlling mechanism of slabbing failure of rockmass by prestressed anchor bolts

作　　者：周辉[1] 徐荣超[1,2] 张传庆[1] 卢景景[1] 孟凡震[1] 沈峥[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点试验室,湖北武汉430071 [2]华北水利水电大学资源与环境学院,河南郑州450011

出　　处：《岩土力学》2015年第8期2129-2136,共8页Rock and Soil Mechanics

基　　金：国家重点基础研究发展计划(973)项目(No.2014CB046902);中国科学院科技创新"交叉与合作团队"(人教字〔2012〕119号);中国科学院知识创新工程重要方向项目(No.KZCX2-EW-QN115);国家自然科学基金项目(No.41172288;No.51279201)

摘　　要：为探究预应力锚杆对岩体板裂化破坏的控制机制,首先进行了岩体板裂化破坏的室内物理模型试验,并运用FLAC数值模拟技术,模拟了平面应变状态下板裂化破坏的形成过程;在此基础上,通过3种不同的预应力锚杆施加方案,进行预应力锚杆对岩体板裂化破坏控制机制的数值试验。研究结果表明:预应力锚杆的作用削弱了裂隙尖端应力集中现象,有效地抑制了岩体内裂隙的扩展与贯通、板裂化破坏的形成;作用在板裂区边界的预应力锚杆,不仅能够抑制板裂化破坏的形成,而且能在一定程度上控制板裂化破坏的范围;作用在板裂破坏区内的预应力锚杆,可有效限制板裂岩体向临空面的位移,体现出提高板裂岩体整体变形刚度的作用。研究结果对认识深埋隧洞围岩板裂化破坏的形成机制、板裂化破坏的合理支护控制以及岩爆防治具有重要指导价值。To investigate the mechanisms of the prestressed anchor bolts in controlling the slabbing failure of rock mass, laboratory physical model experiments on slabbing failure are conducted and the forming process of slabbing failure in plane strain condition is simulated by using the FLAC simulation technology. On the basis of above work, numerical experiments based on three different applying schemes of prestressed anchor bolts are conducted to reveal the mechanisms of the prestressed anchor bolts in controlling the slabbing failure process. The results show that the effect of the prestressed anchor bolts manifest in weakening the concentration effect of stress near crack tip, restraining the crack propagation, coalescence and the slabbing failure process; when applied on the edge of slabbing failure zone, prestressed anchor bolts can not only effectively restrain the formation of slabbing failure but also control the scope of slabbing failure to some extent; when applied in the slabbing zone, prestressed anchor bolts have significant effect in restricting the displacements of the free surface of rock sample, improving the overall stiffness of the slabbing rock. The research results of this paper are of significant importance in understanding the formation mechanisms of slabbing failure, reasonable support control measures of slabbing failure and also rockburst prevention in deep tunnels.

关 键 词：板裂化破坏 模型试验 预应力锚杆 控制机制 数值模拟 

分 类 号：TU470[建筑科学—结构工程]