强力锚杆锚索联合支护预紧力匹配性试验研究

为了解决强力锚杆锚索联合支护时各自施加预紧力存在的匹配性问题，采用FLAC^3D数值模拟软件，对山西潞安环能股份公司漳村煤矿西下山回风巷在不同锚杆（锚索）预紧力下的围岩应力场分布规律进行了模拟分析。结果表明:预应力及其扩散是锚杆锚索发挥主动支护作用的关键因素；预紧力的施加在顶板表面形成压应力区的同时，也使得锚杆锚索的端部出现大小不等的拉应力区；当强力锚杆预紧力不低于85 kN且强力锚索预紧力不低于250 kN时，二者组合支护在顶板所形成的压应力区的连续性才具有支护作用，但是当锚杆预紧力大于140 kN或锚索预紧力大于350 kN后，再增加预紧力对压应力区的扩展效果不明显。根据数值模拟结果并综合考虑支护效果和施工工艺，建议进行强力锚杆锚索组合支护时，85~140 kN锚杆预紧力匹配250~350 kN锚索预紧力比较合理。

Experimental study on pre-tightening force matching ability of intensive bolt and cable combined supporting

To study the matching problem between intensive bolt and cable pre-tightening force，a FLAC^3D numerical simulation software was applied in this article to research the stress field distribution of surrounding rock under different bolt and cable pre-tightening forces of west down-dip return airway in Zhangcun Coal Mine of Shanxi Lu′an Environmental Energy Development Co.，Ltd. The results show that，the pre-tightening force and its diffusion were key factors for the bolt and cable to play active supporting effect. Pre-tightening force force applied compressive stress zone on the surface of roadway roof，but also made the end of the bolt and cable form tensile stress zone at the same time. When pre-tightening force of intensive bolt was not less than 85 kN and pre-tightening force of intensive cable was not less than 250 kN，the continuity of compressive stress zone formed by the two composite supporting had a supporting role. But the effect of compressive stress zone expansion was not obvious when the bolt′s pre-tightening force was greater than 140 kN or the cable′s pre-tightening force was greater than 350 kN. According to the results of numerical simulation and considering the supporting effect and construction technology，it is suggested that the intensive bolt′s pre-tightening force 85~140 kN matched with the intensive cable′s pre-tightening force 250~350 kN is reasonable.