深部破碎软岩巷道围岩稳定性分析及控制  

Analysis and control of stability of the fractured soft rock surrounding a deep roadway

作　　者：何富连[1] 张广超[1] 

机构地区：[1]中国矿业大学(北京)资源与安全工程学院,北京100083

出　　处：《岩土力学》2015年第5期1397-1406,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.51234005);国家重点基础研究发展计划(No.2010CB226802);中央高校基本科研业务费专项资金资助(No.2010YZ02)

摘　　要：针对深部破碎软岩巷道围岩稳定性控制难题,以邢东矿-980车场巷道为研究对象,采用现场调研、数值模拟、井下试验及现场观测等方法分析围岩变形破坏特征,揭示其破坏机制,针对性地提出了以高强锚杆密集支护、新型喷层结构护表、滞后注浆加固为主体的多层次锚喷网注联合支护系统,详细阐明了具体支护措施的围岩控制机制,并用数值方法分析了锚杆间距、喷层厚度对于围岩应力场和位移场的影响规律。研究表明:(1)随着锚杆间距减小(0.7 m→0.3 m),锚杆承压拱和喷层结构的承载能力呈幂函数增长趋势,锚固区围岩压应力呈线性增长趋势,围岩变形量明显降低;(2)随着喷层厚度增大,喷层结构承载能力近似线性增长,锚固区围岩压应力亦呈增长趋势,各部位围岩位移量显著降低;(3)当喷层厚度达到200 mm时,非锚固区内围岩大部分处于压应力状态,拉应力区大幅减少。基于上述研究,结合现场地质、生产条件确定试验巷道围岩支护方案,并进行现场应用。工程实践表明,多层次锚喷网注联合支护技术可有效控制深井破碎软岩巷道围岩大变形,实现深井巷道围岩的稳定性控制。To resolve the stability control problem related to the fractured soft rock surrounding deep roadways, a case study is performed on the Xingdong Mine-980 roadway tunnel to investigate the characteristics and mechanism of the deformation and failure of the surrounding rock mass, with combining the procedures of field investigation, numerical simulation, in-situ testing and monitoring and so on. A bolt-shotcrete-net-grouting combined supporting system is developed, which is composed of densely distributed high-strength anchors, newly shotcrete protecting layer and time-lag grouting reinforcement. The controlling mechanism is explored for the surrounding rockmass stability with different types of supporting structures, and a numerical analysis is performed on the influence of bolt spacing and shotcrete layer thickness on the stress and displacement fields of the surrounding rockmass. It is shown that： 1） With the bolt spacing decreasing from 0.7 m to 0.3 m, the bearing capacities of anchor bearing arch and shotcrete layer structure increase following a power law, the compressive stress in the anchorage zone increases practically linearly and the displacement of surrounding rock decreases sharply; 2） When the shotcrete layer thickness increases, the bearing capacity of shotcrete layer structure increases linearly, similar to the compressive stress in anchorage zone; meanwhile, the displacement of surrounding rock decreases substantially; 3） When the layer thickness reaches 200 mm, compression prevails in most part of the surrounding rock without anchors, and the tensile stress zone shrinks significantly. Based on the above simulations, a supporting scheme is proposed and implemented for an experimental roadway with combining production and geological conditions. The field practice shows that bolt-shotcrete-net-grouting combined supporting technique can effectively control the large deformation of surrounding rock.

关 键 词：破碎软岩巷道 高强喷层 喷层厚度 锚杆间距 

分 类 号：TU457[建筑科学—岩土工程]