针对深部回采巷道围岩变形导致锚杆支护失效的问题，提出通过改善锚杆受力状态、改变锚杆锚固方式、优化杆体形状，减少锚杆破断的方法，在此基础上，设计了1种新外形结构的螺纹钢锚杆。进行了实验室拉拔试验，结果表明：矿用右旋锚杆、左旋锚杆和大肋间距高强锚杆的平均拉拔力为136.9、106.1、147.6 kN，且大肋间距高强锚杆吸能效果更好。在现场试验前，先对回风巷的围岩结构进行探测，包括顶板钻孔窥视和松动圈测试，依据围岩结构探测结果，确定最终的巷道支护方案。回风巷采用原支护方案和大肋间距高强锚杆全锚支护2种方案支护，并对顶板离层和锚杆受力进行实时监测，试验结果表明：大肋间距高强锚杆支护的巷道顶板最大下沉量较原支护方案减小36.4%，顶板离层量较原支护方案降低24.1%；顶板和两帮锚杆受力的结果显示大肋间距高强锚杆支护较原支护方案锚杆受力更小，两种支护方案顶板锚杆受力最大值分别为442.9 MPa和78.1 MPa，改进方案较原支护方案降低了82.4%；其回采期间，全锚大肋间距高强锚杆支护方案与原支护方案相比，支护失效锚杆数量明显减少，这都表明全长锚固的大肋间距高强锚杆更有利于维护巷道的稳定。

Aiming at the problem of bolt support failure caused by surrounding rock deformation in deep mining roadway,a method was proposed to reduce the bolt breakage by improving the bolt stress state, changing the anchoring mode and optimizing the shape of rod body. On this basis, a new rebar anchor rod with a new shape and structurewas designed. Laboratory tests show thatthe average pull-out force of the right-hand bolt, the left-hand bolt and the high strength bolt with large rib spacings are 136.9 kN, 106.1 kN and 147.6 kN, andthe large-rib spacing high-strength bolts absorb energy better result. Before the field test, the surrounding rock structure of the return air roadway was detected, including roof drilling and loose circle testing. The final roadway support scheme was determined according to the detection results of surrounding rock structure. The original supporting scheme and full bolt supporting scheme were adopted for the return roadway, and the roof separation and bolt stress were monitored in real time. The test results show that the maximum roof subsidence of roadway supported by high-strength bolt with large rib spacing is reduced by 36.4% compared with the original support scheme, and the roof separation amount is reduced by 24.1% compared with the original support scheme. The results of the stress on the roof and two side bolts show that the stress of high-strength bolt with large rib spacing is smaller than that of the original support scheme, and the maximum stress of roof bolt is 442.9 MPa and 78.1 MPa respectively, and the improved scheme is reduced by 82.4% compared with the original support scheme. At the same time, compared with the original support scheme, the failure of bolt support is significantly reduced, which indicates that the full-length anchored high-strength boltwith large rib spacingis more conducive to maintain the stability of roadway. 

0 引言

1 巷道支护失效分析

   1.1 锚杆失效形式

   1.2 减少锚杆失效的方法

2 拉拔测试

3 现场工业试验

   3.1 试验方案

   3.2 锚固效果监测

   3.3 锚杆支护效果分析

4 结论