基于Flac3D数值模拟的软弱岩体联合支护机理研究  

Research on Combined Supporting Mechanism of Fractured Rock Mass Based on Flac3D Numerical Simulation

作　　者：周国军 贺严[2] ZHOU Guo-jun;HE Yan(Hunan Nonferrous Credit Project Supervision Co.,Ltd.,Changsha 410007,China;School of Resources and Safety Engineering,Central South University,Changsha 410012,China)

机构地区：[1]湖南有色诚信工程监理有限责任公司,湖南长沙410007 [2]中南大学资源与安全工程学院,湖南长沙410012

出　　处：《有色矿冶》2019年第5期6-10,共5页Non-Ferrous Mining and Metallurgy

基　　金：湖南省教育厅科研基金项目“大水矿山地下开采岩体稳定性分级”(编号:17C1375)

摘　　要：为解决矿山深部高应力破碎岩体巷道围岩变形严重、施工风险高、使用周期短等问题,以安徽某铁矿为例,通过现场调研、理论分析、Flac^3D数值模拟及在线监测相结合的方法,针对深部-440 m中段进路开挖后支护困难的问题,提出了锚网喷注联合支护技术,在探究高性能预应力锚杆、金属网、喷射混凝土及注浆补强联合作用机理的基础上,对其施工关键技术难题开展了系统研究,并通过围岩松动圈测试及围岩表面位移监测等方法对联合支护效果进行评价。研究结果表明:深部进路开挖后,顶板竖直位移为1 183.8 mm,竖向应力达到15.85 MPa,围岩变形破坏严重,单一支护措施无法满足安全高效采矿作业的要求,锚网喷注联合支护技术将锚杆、金属网、喷射混凝土、注浆等多种支护手段充分结合,形成复合支护结构,扩大了支护体系的承载范围,锚喷网注联合支护作用下的围岩松动圈面积仅为原来的48.8%,围岩顶板竖向位移为385.6 mm,与原顶板竖向位移相比降低了66.1%,围岩稳定性显著提高,是使深部软弱围岩形成长期稳定整体的有效手段。In order to solve the problems of serious fractured rock deformation,high construction risk and short service period of roadway with high stress in deep mine.Taking an iron mine of Gushan Mining Company as an example,the bolt-mesh-concrete-grouting combined support technology was proposed in-440 m section by methods of field investigation,theoretical analysis,Flac 3D numerical simulation and on-line monitoring.To explore the action mechanism of high-prestress bolt,metal mesh,concrete and grouting reinforcement,the key technical problems were systematically studied and the effect of combined supporting was evaluated by means of loosening zone test and displacement monitoring.The results showed that:the vertical displacement was 1 183.8 mm and vertical stress was 15.85 MPa after excavated.Single supporting measure could not meet the requirements of safety and efficiency,but the bearing capacity was enhanced by the combined support structure.The area of surrounding rock loose zone reduced to 48.8%,and the vertical displacement of 385.6 mm was 66.1%lower than that of the original rock.It was indicated that the bolt-mesh-concrete-grouting combined support technology has become an effective way to form a long-term stable entirety with deep fractured rock.

关 键 词：软弱围岩 FLAC^3D 联合支护 稳定性评价 

分 类 号：TD856.13[矿业工程—金属矿开采]