应变软化挤压岩体巷道扩挖力学响应研究  

Mechanical Response Study on the Roadway Re-profiling Work in Squeezing Rock Mass Involving Strain-softening Behavior

作　　者：关凯[1] 刘洪磊[1] 高振领[2] 孙星 王京生 付秋波 苏环 Guan Kai;Liu Honglei;Gao Zhenling;Sun Xing;Wang Jingsheng;Fu Qiubo;Su Huan(Institute of Rock Instability and Seismicity Research,Northeastern University,Shenyang 110819,China;Yantai Design&Research Engineering Co.,Ltd.,Shandong Gold Group,Yantai 261438,China;Xincheng Gold Mine,Shandong Gold Mining Co.,Ltd.,Yantai 261438,China)

机构地区：[1]东北大学岩石破裂与失稳研究所,辽宁沈阳110819 [2]山东黄金集团烟台设计研究工程有限公司,山东烟台261438 [3]山东黄金矿业股份有限公司新城金矿,山东烟台261438

出　　处：《金属矿山》2020年第1期115-121,共7页Metal Mine

基　　金：“十三五”国家重点研发计划项目（编号：2016YFC0801607）;国家杰出青年科学基金项目（编号：51525402）

摘　　要：针对深部高应力软弱破碎岩体巷道变形侵限及重复返修维护的问题,基于有限变形理论和Lagrange物质观点,建立了考虑岩体峰后行为的大变形巷道重塑扩挖力学模型,实现了重复开挖扰动引起围岩累积劣化的定量表征,依次分析了不同岩体条件下维持巷道净断面所需的最小刚性支护载荷和返修效率,同时对实际工程中超前导洞施工法用于释放主洞围岩压力和挤压势的有效性进行了探讨。研究结果表明:①巷道的重塑扩挖是控制挤压变形的有利方式,能显著降低岩石压力和作用在支护结构上的载荷,并得到了基于洞壁收敛位移的巷道稳定性图表;②重塑扩挖施工需事先尽量释放初次开挖产生的应力和变形能,以提高巷道的返修效率;③超前导洞施工法对于降低主洞洞壁变形以及释放围岩压力的有效性与其开挖尺寸和岩体峰后本构关系密切相关,当导洞半径较大(至少超过0.3~0.5倍主洞设计尺寸)及岩体呈现出应变软化或理想塑性特征时,超前导洞施工法能有效改善主洞附近的围岩应力条件,降低挤压势和洞壁收敛变形。Centered on the problems including the significant reduction in cross-section of roadway and its repetitivemaintenance in deep soft and fractured rock mass,this paper developed the mechanical model of re-profiling of a squeezingroadway considering the post-peak behavior of rock mass according to the finite strain theory and Lagrangian material descrip-tion,the accumulated strength degradation of surrounding rock subjected to repetitive excavation disturbances is quantified.Then some practical questions are addressed with respect to the required minimum rigid support pressure to achieve the de-sired profile and the re-profiling efficiency.In addition,the effectiveness of advancing a pilot tunnel to release high stress anddeformtion is investigated under different conditions.The study results show that:(1)re-profiling work is an effective way to con-trolling the large deformation and alleviating the rock pressure as well as the load on a rigid support,and a stability graph withrespect to wall convergence is obtained;(2) the concentrated stress and squeezing potential of rock mass should be released inadvance,which is beneficial to enhancing the efficiency of roadway maintenance;(3)the effectiveness of advancing a pilot tun-nel to release high stress and deformation is closely related to its excavation size and post-peak behavior of rock mass,if thepilot tunnel size is large(more than 30% ~ 50% of the main tunnel radius) and the strain-softening or perfectly-plastic behav-ior of rock mass is presented,the construction method of advancing a pilot tunnel is beneficial to reducing the squeezing poten-tial and large deformation of the main tunnel.

关 键 词：深部开采 大变形 扩挖 应变软化行为 超前导洞 有限变形理论 

分 类 号：TD853[矿业工程—金属矿开采]