深部破碎岩体巷道围岩控制技术研究

Study on Surrounding Rock Control Technology of Roadway in Deep Fractured Rock Mass

某金矿进入深部开采后,由于围岩破碎,巷道开挖后出现了明显的变形和破坏现象,难以满足其服务期间的稳定性要求。针对这一问题,采用现场调查、数值模拟和现场试验等手段开展了研究。首先,分析了巷道变形和破坏特征,认为该矿巷道破坏表现为两帮破坏,然后发展至顶板。其次,从充分利用深部破碎岩体自承能力的角度出发,提出了马蹄形巷道设计方案,并采用数值模拟的方法分别模拟了矩形巷道,直墙半圆拱巷道,直墙三心拱巷道和马蹄形巷道的开挖过程,结果显示当采用马蹄形巷道时,能够减小围岩应力松弛区的范围,改善围岩的受力条件,极大限度地抑制了围岩的变形和破坏。再次,给出了优化的马蹄形巷道支护方案,在传统只采用顶板锚杆的基础上增加两帮锚杆和穿带,其中,顶板锚杆间距1.5 m,两帮锚杆间距1.0 m,排距均为1.0 m。最后,将得到的马蹄形巷道方案应用到该矿-900 m分段联巷的工程实践当中,结果表明马蹄形巷道施工后围岩没有发生明显的变形和破坏,取得了较好的施工效果,保证了巷道的稳定性。通过本研究可以为该种类型的深部破碎岩体巷道的围岩控制技术提供参考和借鉴。

Because of the broken surrounding rock,there were obvious deformation and destruction phenomena after roadway excavation when a gold mine entered into deep mining,which was difficult to meet the stability requirements during its service period.In order to solve these problems,field investigation,numerical simulation and field test were carried out.Firstly,the characteristics of roadway deformation and failure were analyzed.It was considered that the roadway failure in this mine was characterized by two sides of failure,and then developed to the roof.Secondly,from the view of fully utilizing the self-supporting capacity of surrounding rock,the design scheme of roadway with horseshoe-shaped section was put forward.The stress characteristics of rectangular roadway,straight wall semi-circular arch roadway,straight wall three-core arch roadway and horseshoe-shaped roadway were simulated by numerical simulation.The results showed that when the horseshoe-shaped roadway was adopted,the range of stress relaxation zone could be reduced,the stress conditions of surrounding rock could be improved,and the deformation and failure of surrounding rock could be restrained to the greatest extent.Thirdly,the optimum supporting scheme of horseshoe-shaped roadway is given.On the basis of traditional supporting roof bolts,two sides of bolts and through strips were added.Among them,the roof bolt spacing was 1.5 m,the two sides of bolts spacing was 1.0 m,and the row spacing was 1.0 m.Finally,the obtained horseshoe-shaped roadway was applied to the engineering practice of-900 m sublevel combined roadway in the mine.The results show that there is no obvious deformation and failure of the surrounding rock after horseshoe roadway construction,which has achieved good construction results and ensured the stability of the roadway.The study provided references for the surrounding rock control technology of this type of deep fractured rock mass roadway.