综放沿空煤巷不同预应力锚杆锚索支护效果分析

Analysis on Support Results of Different Pre-stressed Bolt/Anchor in Seam Gateway Along Goaf of Fully Mechanized Top Coal Caving Mining Face

为了有效控制综放沿空煤巷在掘进期间的变形破坏,在不考虑原岩应力的情况下,采用FLAC3D计算程序分别模拟了锚杆、锚索、锚杆+锚索3种支护条件下施加预应力后在围岩中形成的附加应力场分布情况,分析了锚杆锚索施加预应力后对围岩的作用机理。计算了不同锚杆预应力值时沿空巷道的支护效果,现场工业试验表明:当锚杆预紧力达到30 kN时,不但对控制掘进期间沿空巷道围岩变形效果好,也能效控制回采期间围岩变形。

In order to effectively control the deformation failure occurred during the gateway driving period of the fully mechanized top coal caving mining face gateway along the goal, under the condition of the in situ rock stress not considered, the FLAC30 calculation program was applied to simulate the distribution condition of the additional stress field in the surrounding rock under the three type support condi- tions with the bolt, anchor or bolt plus anchor with pre-stressed force applied. The paper analyzed the function mechanism of the bolt,/an- chor after pre-stressed to the surrounding rock. The paper calculated the support results of the gateway along the goal with different pre- stressed values of the bolts. The site industrial trial showed that when the pre-tension force of the bolt reached at 30 kN, the deformation results of the surrounding rock in the gateway along the goaf would be good during the controlled driving period and also the surrounding rock deformation would be effectively controlled during the coal mining period. The research results could provide the theoretical and tech- nical basis to ensure the stability of the seam gateway along the goaf during the gateway driving and the coal face mining period.