综放沿空留巷顶板锚杆剪切变形分析与控制

ANALYSIS OF SHEARING DEFORMATION OF ROOF SUPPORT BOLT AND ITS CONTROL IN GOB-SIDE ENTRY RETAINING OF FULLY-MECHANIZED CAVING FACE

实现综放大断面沿空留巷,对综放开采技术的发展具有十分重要的意义,但综放大断面沿空留巷围岩稳定性控制是一项技术性难题,其支护必定要经受大变形的考验,可能会影响到传统锚杆支护中的锚杆受力状态的改变。应用结构分析软件ANSYS对综放沿空留巷顶板锚杆剪切变形特征进行了数值模拟,着重研究了锚杆的剪切力随老顶回转角度和锚杆布置倾角的变化规律。研究结果表明,采用传统设计的综放大断面沿空留巷顶板锚杆在大变形情况下将发生显著剪切变形,甚至会被剪断,但如果适当调整锚杆支护设计方案,即适当调整顶板锚杆的倾角,就可以显著降低顶板锚杆所承受的剪切力,其效果得到物理模拟试验和井下工业性试验的验证。

It is an important significance in the technique development of fully-mechanized caving face（FCF） to develop the large-section gob-side entry retaining in FCF, but the stability control of surrounding rock of large-section gob-side entry retaining in FCF becomes a technically difficult problem; and its support ways will endure the test of large deformation, which probably has an influence on the stress state of bolt in traditiOnal bolt supporting. The software ANSYS is applied to simulate the shearing deformation characters of bolt through roof in gob-side entry retaining and the rule that shear stress of the bolt changes with turning angle of main roof and obliquity of the bolt distribution is noted. The result indicates that the roof support bolt has obvious shearing deformation in the course of huge deformation or even shearing fracture if the traditional designed large-section gob-side entry retaining in FCF is adopted. If the design scheme of bolt supporting is adjusted properly, i.e., the inclination of roof support bolt is adjusted properly, the shearing force that the bolt is supported will reduce obviously, whose effect has been verified by the physical simulation and the underground industrial test.