倒梯形巷道顶板全长锚索联合支护技术研究

Research on Combined Support Technology of Full-length Anchor Cable in Roof of Inverted Trapezoidal Coal Roadway

针对长城五矿1902S回风巷倒梯形煤巷的高地应力产生的围岩稳定性差,支护体失效的问题,在实地调研施工现场后,结合FLAC3D数值模拟分析原方案的支护失效体制,并提出“全长锚固锚索+组合支撑钢墩柱+W型钢带+钢筋锚网+钢带”的联合支护技术,从顶板围岩的变形量和帮部相对移近量两方面来分析矿压显现规律。结论如下:原方案锚杆锚索的组合支护体应力偏分布,不能解决倾斜顶板帮角处出现的应力集中现象,全长锚索支护对应顶板离层和应力集中位置,并采用支撑钢墩柱对顶帮角处进行补强支护,矿压监测数据显示,该技术明显改善了顶板的围岩稳定性,有效地减轻了帮部的压力和变形,锚索的承拉效果明显强于锚杆,为解决不规则巷道的顶板支护提供了重要的实践经验。

Aiming at the problem of poor stability of surrounding rock and failure of support body caused by high ground stress in the inverted trapezoidal coal roadway of 1902S return air roadway in Great Wall No.5 Coal Mine,after investigating the construction site on the spot,combined with FLAC3D numerical simulation,the support failure system of the original scheme is analyzed,and the combined support technology of"full-length anchor cable+combined support steel pier column+W steel strip+steel bar anchor net+steel strip"is proposed.The law of mine pressure appearance is analyzed from two aspects:the deformation of roof surrounding rock and the relative displacement of the side.The conclusions are as follows:The stress distribution of the combined support body of the bolt and anchor cable in the original scheme is biased,which cannot solve the stress concentration phenomenon at the corner of the inclined roof.The full-length anchor cable support corresponds to the roof separation and stress concentration position,and the supporting steel pier column is used to reinforce the support at the corner of the roof.The mine pressure monitoring data show that the technology significantly improves the stability of the surrounding rock of the roof and effectively reduces the pressure and deformation of the side.The tensile effect of the anchor cable is obviously stronger than that of the bolt,which provides an important practical significance for solving the roof support of the irregular roadway.