高地应力不同断面形状巷道围岩破坏特征及支护试验研究

发布时间：2019-05-13 18:26

【摘要】：我国煤矿开采深度在逐年增加,中东部一些矿井已经进入深部开采。深部矿井面临更为复杂的开采环境,尤其是巷道支护难题日益凸显。其中,高地应力是造成深部巷道变形破坏严重的重要因素,严重影响矿井的安全生产和高产高效,高地应力巷道围岩控制已经成为深部开采亟需解决的难题。因此,研究高地应力巷道围岩破坏特征及控制对深部开采具有重要的指导意义。本文在对高地应力巷道变形破坏现状调研的基础上,采用理论研究、相似材料模拟试验相结合的研究方法,分析了深部高地应力巷道围岩变形破坏的影响因素、破坏特点及变形破坏机理,介绍了巷道锚杆支护理论及支护机理,研究了高地应力圆形、矩形两种断面巷道围岩破坏特征,采用目前高地应力巷道常用的支护方式进行支护效果对比,并给出了一些补强和支护的建议。主要得出如下结论:(1)研究了λ1状态下高地应力圆形巷道围岩破坏特征。在巷道开挖后,两帮围岩表面形成的切向应力集中超过其强度而发生剪切破坏,受上、下剪切滑移裂隙交汇切割,两帮围岩呈“楔形”破坏区域;剪切滑移裂隙延伸至顶板并相互交汇使顶板出现块状冒落,并呈现“月牙状”;剪切滑移裂隙延伸至底板并沿底板层理面发育,底板破坏呈现“盆底”状。(2)圆形岩层巷道采用锚网索喷的支护方式,与裸巷的破坏范围和顶底板变形量进行了对比。得出顶板下沉量减小13.3mm,底板底鼓量减小3.8mm,两帮破坏范围减小约30mm。锚网索喷支护有效控制了巷道围岩的变形破坏,支护效果较好。(3)研究了λ1状态下高地应力矩形巷道围岩破坏特征。在巷道开挖后,顶底角处形成的应力集中超过其强度而发生剪切破坏,随后两帮围岩出现片帮,并呈“弧形”片落;顶板下沉挠度增大,出现拉伸破断和离层现象;底板在水平挤压应力作用下发生剪切错动并出现离层。(4)矩形煤层巷道采用锚梁网索的支护方式,与裸巷的破坏范围和顶底板变形量进行了对比。得出顶板下沉量减小27.7mm,底板底鼓量减小3.9mm,两帮破坏范围减小约70mm。锚梁网索支护有效控制了巷道围岩的变形破坏,支护效果较好。
[Abstract]:The mining depth of coal mines in China is increasing year by year, and some mines in central and eastern China have entered deep mining. Deep mines are facing more complex mining environment, especially the difficult problem of roadway support is becoming more and more prominent. Among them, high ground stress is an important factor causing serious deformation and failure of deep roadway, which seriously affects the safety of mine production and high yield and high efficiency. The control of surrounding rock of high ground stress roadway has become an urgent problem to be solved in deep mining. Therefore, it is of great significance to study the failure characteristics and control of surrounding rock in high ground stress roadway for deep mining. Based on the investigation of the present situation of deformation and failure of high ground stress roadway, this paper analyzes the influencing factors of surrounding rock deformation and failure of deep high ground stress roadway by means of theoretical research and similar material simulation test. The failure characteristics and deformation failure mechanism are introduced, the theory and supporting mechanism of roadway bolt support are introduced, and the failure characteristics of surrounding rock of roadway with high ground stress circle and rectangle section are studied. The supporting effects of high ground stress roadway are compared, and some suggestions for reinforcement and support are given. The main conclusions are as follows: (1) the failure characteristics of surrounding rock of high ground stress circular roadway under 位 1 state are studied. After roadway excavation, the shear failure occurs because the tangential stress concentration on the surface of the two sides of surrounding rock exceeds its strength, and the two sides of surrounding rock are cut by the intersection of upper and lower shear slip cracks, and the two sides of surrounding rock are in the form of "cuneiform" failure area. The shear slip crack extends to the roof and intersects with each other, resulting in massive caving of the roof, and presents a "crescent shape". The shear slip crack extends to the floor and develops along the floor layer, and the failure of the floor is "basin bottom". (2) the circular roadway is supported by anchor mesh cable spray, which is compared with the failure range of the bare roadway and the deformation of the top and bottom plate. It is concluded that the subsidence of the roof is reduced by 13.3 mm, the bottom drum of the bottom plate is reduced by 3.8 mm, and the failure range of the two sides is reduced by about 30 mm. Anchor, mesh, cable and shotcrete support can effectively control the deformation and failure of surrounding rock of roadway, and the supporting effect is good. (3) the failure characteristics of surrounding rock of rectangular roadway with high ground stress under 位 1 state are studied. After roadway excavation, the stress concentration at the top and bottom angle exceeds its strength and shear failure occurs, and then the two sides of surrounding rock appear as "arc" sheet fall, and the subsidence and deflection of roof increases, and the phenomenon of tensile fracture and layer separation occurs. Shear dislocation and separation of floor occur under the action of horizontal extrusion stress. (4) the supporting mode of anchor beam mesh cable is adopted in rectangular coal seam roadway, which is compared with the failure range of bare roadway and the deformation of roof and floor. The results show that the subsidence of the roof is reduced by 27.7 mm, the bottom drum of the bottom plate is reduced by 3.9 mm, and the failure range of the two sides is reduced by about 70 mm. Anchor beam, mesh and cable support can effectively control the deformation and failure of surrounding rock of roadway, and the supporting effect is good.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD353

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