摘要
随着开采条件的复杂化,巷道围岩裂隙发育程度较高,极大的影响了围岩空间的稳定性,造成大量巷道难于维护。为进一步深入研究裂隙岩体巷道工程特征并提出相应的控制对策,基于现场调研与理论研究分析了裂隙发育岩体巷道及典型支护结构体的变形破坏特征,采用三测线不连续面量测方法对煤矿现场的裂隙发育情况作了调查统计,利用离散裂隙网络(DFN)在FLAC^(3D)软件中对矿山现场调查得到的裂隙进行了重构还原,与现场监测数据对比分析后认为,裂隙重构模型能作为支护设计时不同支护方式和支护参数效果对比的定性参考;分析了我国南方地区部分矿区常规支护方式下典型裂隙巷道围岩变形破裂特征;提出了提高支护系统的初期支护刚度与强度、充分利用深层稳固岩体的承载功能、扩大支护系统的承载面积、准确把握支护系统,尤其是被动支护与主动支护的临界支护刚度、有效提高裂隙岩体的完整性及承载强度等5个裂隙岩体控制要点;运用叠加压缩拱承载理论,提出了以“长、短”锚杆(锚索)承载体系和可控注浆加固“内、外”结构承载为基础的联合控制技术,基于数值计算验证认为,该方案能消除或减小巷道围岩拉应力区,有效阻止裂隙围岩体的拉剪破坏形成松动变形。现场监测数据表明:在4个月的观测期间内,巷道两帮移近量0.1 m,顶底板移近量0.12 m,最终变形速率低于0.2 mm/d,说明以“长、短”锚杆(锚索)并结合注浆加固的支护方案能有效控制裂隙岩体巷道的大变形。
The mining conditions of underground coal mines are complex.The development degree of surrounding rock fissures of underground roadways is high,significantly affecting roadways’stability and making a large number of them difficult to maintain.To further study the engineering characteristics of fractured rock roadway and put forward corresponding control measures,the deformation and failure characteristics of fractured rock roadway and typical supporting structure are analyzed based on field investigation and theoretical research.The fracture development in the coal mine is investigated and counted using three line discontinuity measurement method.The discrete fracture network(DFN)is used to reconstruct and restore the fractures obtained from on-site survey in FLAC^(3D).After comparing with the field monitoring data,it is considered that the fracture reconstruction model can be used as a qualitative reference for the comparison of the effects of different support methods in support design.The deformation and fracture characteristics of typical fractured roadway surrounding rock in some southern China mining areas are analyzed.Five control points of fractured rock mass are put forward,including improving the initial support stiffness and strength of the support system,making full use of the bearing function of deep stable rock mass,expanding the bearing area of the support system,accurately grasping the necessary support stiffness of the support system,especially the passive support and active support,and effectively improving the integrity and bearing strength of fractured rock mass.Using the bearing theory of superimposed compression arch,a combined control technology is proposed,which is based on the bearing system of“long-short”bolt(anchor cable)and the controlled grouting reinforcement of“internal-external”structure.Based on the numerical calculation,it is considered that the scheme can eliminate or reduce the tensile stress zone of the roadway surrounding rock,and effectively prevent the loose deformation caused by the tensile shear failure of the rock mass.Field tests were carried out at Mukong Coal Mine,Guizhou Province,China.The on-site monitoring data shows that the two sidewalls’approach distance is 0.1 m during the four-month observation period.The roof-floor’s approach distance is 0.12 m.The final deformation rate is less than 0.2 mm/d,indicating that the support scheme of“long-short”anchor(anchor cable)combined with grouting reinforcement can effectively control the fractured rock roadway’s large deformation.
作者
余伟健
李可
芦庆和
郭涵潇
杜少华
YU Weijian;LI Ke;LU Qinghe;GUO Hanxiao;DU Shaohua(School of Resource&Environment and Safety Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;Hunan Provincial Key Laboratory of Safe Mining Techniques of Coal Mines,Hunan University of Science and Technology,Xiangtan 411201,China;College of Mining,Guizhou Institute of Technology,Guiyang 550003,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2021年第11期3408-3418,共11页
Journal of China Coal Society
基金
国家自然科学基金资助项目(51974117)
湖南省自然科学基金资助项目(2020JJ4027)
贵州理工学院学术新苗资助项目(GZLGXM-02)。
关键词
裂隙调查
裂隙重构
可控注浆
协调承载
变形控制
fracture investigation
fracture reconstruction
controllable grouting
coordinated load-supporting
deformation control