火成岩侵入体不规则性及巷道围岩压力显现规律研究

侵入煤系地层的火成岩,其发育特征及赋存形态表现出有别于沉积岩层的不规则性,受此影响,沿火成岩侵入体顶板下掘进的煤巷,其围岩应力分布复杂,压力显现程度不一,局部围岩长期变形难以自稳,给巷道的支护及后期维护带来极大挑战。针对这一情况,从火成岩侵入层位、侵入体顶板形态两方面分析了火成岩侵入体顶板的不规则性,归纳出不规则火成岩侵入体顶板的发育原理、表面形态及岩性物理特征,在此基础上,结合工作面现场围岩破坏特征,利用Flac 3D数值模拟软件模拟多类不规则火成岩侵入体顶板条件下巷道围岩应力分布情况,分析总结出不规则火成岩侵入体顶板条件下巷道围岩压力显现规律。研究结果表明,顺煤侵蚀火成岩顶板下巷道围岩两帮较沿直接顶层间侵入火成岩顶板条件下压力显现更强烈,围岩更易遭受破坏。

Study on roof irregularity of igneous intrusive body and the pressure behavior law of roadway surrounding rock

The development characteristics and occurrence form of igneous rock invading coal measure strata showed different irregularity from sedimentary rock.Affected by this,the stress distribution of surrounding rock of coal roadway driving under the roof of igneous rock intrusive body was complex,the pressure manifestation degree was different,and the long-term deformation of local surrounding rock was difficult to self-stabilize,which brought great challenges to the support and later maintenance of roadway.In this paper,the irregularity of igneous rock intrusion roof was analyzed from two aspects of igneous rock intrusion horizon and intrusive roof shape,and the development principle,surface morphology and lithologic physical characteristics of irregular igneous rock intrusion roof were summarized.On this basis,combined with the surrounding rock failure characteristics of working face,the FLAC 3D numerical simulation software was used to simulate the stress distribution of roadway surrounding rock under the roof conditions of multiple types of irregular igneous rock intrusions,and then the pressure behavior law of roadway surrounding rock under the roof condition of irregular igneous rock intrusion was analyzed and summarized.The analysis results showed that the pressure behavior of roadway surrounding rock under the condition of along coal erosion igneous rock roof was stronger than that under the condition of intruding igneous rock roof along the top floor directly,the surrounding rock was more vulnerable to damage.