采动高应力区沿空掘巷锚杆破断机理

发布时间：2018-06-29 20:09

本文选题：沿空巷道 + 锚杆尾部　；参考：《中国矿业大学学报》2017年04期

【摘要】：针对皖北钱营孜煤矿3_216沿空巷道实体煤侧顶板肩窝处锚杆尾部发生大面积破断现象,分析了断裂锚杆分布区域应力分布及塑性区发育特征,并结合锚杆尾部断裂的力学机理分析,探讨了锚杆破断的机理.根据3_216沿空巷道应力分布特征,将其掘进期间分为3个阶段:上区段固定支承压力影响阶段、上区段支承压力未稳定阶段和稳定阶段,发现实体煤侧顶板肩窝处锚杆破断现象集中出现在矿压显现最为强烈的上区段支承压力未稳定阶段.结果表明:塑性区不断扩展是造成该处锚杆所受拉力增大的主要外因,巷道掘进期间的大变形导致钢带位移致使锚杆尾部应力集中,进而引起锚尾产生裂纹.随着实体煤侧顶板浅部围岩塑性区不断发育,锚杆荷载增大,导致旧裂纹扩展并断裂.
[Abstract]:In view of the large area breaking phenomenon of bolt at the shoulder socket of coal side roof in Qianyingzi Coal Mine 3216 goaf along the goaf, the stress distribution and plastic zone development characteristics of fault anchor are analyzed. Combined with the mechanical mechanism analysis of bolt tail fracture, the mechanism of bolt breaking is discussed. According to the stress distribution characteristics of 3216 roadway along the goaf, the excavation period is divided into three stages: the influence stage of fixed support pressure in the upper section, the unsteady stage and the stable stage of the supporting pressure in the upper section. It is found that the phenomenon of bolt breaking at the shoulder socket of solid coal side roof is concentrated in the stage of unsteady supporting pressure in the upper section, where the rock pressure appears most strongly. The results show that the continuous expansion of the plastic zone is the main external cause of the increase of the tensile force of the anchors there. The large deformation during the tunneling of the roadway leads to the stress concentration at the end of the anchors resulting in the stress concentration at the end of the anchors and then causes cracks in the tail of the anchors. With the development of plastic zone in shallow surrounding rock of solid coal side roof, the load of anchor rod increases, which leads to the extension and fracture of old crack.
【作者单位】：中国矿业大学矿业工程学院深部煤炭资源开采教育部重点实验室;重庆大学三峡库区生态环境教育部重点实验室;山西潞安矿业集团高河能源有限公司;
【基金】：国家自然科学基金项目(51474208) 江苏省自然科学基金项目(BK20161184) 江苏高校优势学科建设工程项目
【分类号】：TD353.6

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