摘要
针对许厂煤矿4302轨巷顶煤裂隙发育、松软破碎、不稳定层厚度大,掘进过程中极易冒落等特点,提出"减小空顶距离+减小空顶时间+提高临时支护初撑力+预应力锚索支护"的支护技术对策;并据此制定了减小循环进尺,强有力的临时支护,左旋高性能预应力螺纹钢锚杆,以及小孔径短锚索加强支护控制顶板的支护方案;采用数值模拟方法比较了新旧支护方案的围岩控制情况.数值模拟表明,随着支护强度的增加,巷道围岩应力状态改善,塑性区范围减小,巷道表面位移得到有效控制,据此确定了最优支护参数并应用于现场施工.实测表明,采用新支护方案后巷道成形较好,围岩变形得到有效控制.
The top coal of 4302 rail roadway in xucnang mine is soft and broken,with a big thickness of its unstable layer and well developed fractures, making it very easy to have a roof falling in the process of roadway excavation. Aiming at this problem, we have suggested four support countermeasures, which are 1） reducing roof exposing distance, 2） reducing roof exposing time, 3） increasing setting pressure of temporary lining, and 4） using prestressed bolt- mesh-anchor support. The specific support scheme is reducing circle footage, having a strong temporary lining, adopting laevorotatory and high performance prestressed screw-thread steel bolts, and strengthening support with small aperture short anchor rope. This new support scheme was compared with the original scheme in surrounding rock controlling situation using numerical simulation, indicating that the stress state in surrounding rock is improved, the plastic zone reduced, and the surface displacement of surrounding rock controlled effectively. Based on this analysis, the optimal support plan is confirmed and applied in practice. The actual measurement indicates that, by using the new support scheme, the roadway is well shaped and the deformation is effectively controlled.
出处
《采矿与安全工程学报》
EI
北大核心
2007年第4期427-431,共5页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(50674085)
中国矿业大学科技基金项目(2005B001)
关键词
松软破碎围岩
不稳定
预应力
及时支护
锚网索支护
soft and broken surrounding rocks
unstable
prestress
support in time
boltmesh-anchor support
