高煤帮巷道锚杆锚索支护合理预紧力匹配设计及应用

巷帮锚杆锚索预紧力不匹配是造成高煤帮巷道支护失效的重要原因之一。文章分析了某矿30211综采工作面回风巷帮锚索崩断射人事故原因,采用FLAC_^3D软件模拟了巷道采用锚杆、锚索联合支护时二者的匹配关系。结果表明：锚杆、锚索两种延伸率差别很大的材料用在同一条巷道的同一侧帮时,延伸率小的锚索承担的载荷较大,先破断； 锚杆、锚索预紧力联合作用在巷道帮部围岩表面及内部附近形成了大小不等的压应力区,随着预紧力的增加,压应力值和范围也在不断扩大； 锚杆的预紧力矩设定在200~300N?m之间,且锚索的预紧力设定在200~250kN之间,是比较合理的匹配方案。研究结果对高煤帮巷道支护设计和施工具有一定的指导意义。

Design and Application of Reasonable Pre-tightening Force of Bolt and Cable Support in Coal Roadway with High Roadside

The mismatch of pre-tightening force of bolt and cable in roadway side is one of the important reasons for the failure of roadway support in high coal side. This paper analyses the cause of the breaking and shooting accident of the anchor rope in the back air roadway of 30211 fully mechanized mining face in a mine, and simulates the matching relationship between the two when the roadway adopts the combined support of anchor rod and anchor rope by FLAC3D software. The results show that when the two materials with different elongation are used in the same side of the same roadway, the load of the anchor cable with small elongation is larger and breaks first; the combined action of the anchor bolt and the pre-tightening force of the anchor cable forms different compressive stress zones on the surface and near the interior of the surrounding rock of the roadway. With the increase of the pre-tightening force, the value and range of the compressive stress are also expanding. The pre-tightening moment of anchor is set between 200 and 300N m, and the pre-tightening force of anchor cable is set between 200 and 250kN, which is a reasonable matching scheme. The research results have certain guiding significance for the design and construction of high coal roadway support.