深埋矿井全煤巷道围岩变形破坏特征与稳定性控制

发布时间：2018-09-13 13:15

【摘要】：本文以大同某矿6#煤回采工作面运输巷为工程背景，结合高应力全煤巷道围岩变形破坏特征、煤巷全断面锚杆索支护包络圈理论、高应力全煤巷道围岩支护参数与方式，综合研究了高应力全煤巷道围岩稳定性控制技术的影响因素。采用煤体原位力学特性试验测定、高应力全煤巷道围岩支护相似模拟、数值模拟、工程应用等方法，对高应力全煤巷道围岩稳定性控制的支护参数及其联合支护方案进行了研究，并在工程施工中对高应力全煤巷道围岩稳定性进行了监测，研究得出以下几点结论： 1、深埋高应力全煤巷道围岩，在高地应力及软岩煤体流变效应的影响下，其巷道围岩煤体原位力学性能强度偏低、自稳能力较差，在高地应力的作用下巷道围岩极易发生坍塌、冒落，高应力全煤巷道围岩的稳定性维护极为困难。对大同某矿6#煤回采工作面全煤巷道围岩煤样进行单轴压缩试验，巷道围岩在力学性质上主要表现为流变、塑性性质，这是造成巷道掘进初期围岩变形量大以及变形速率快的根本原因。 2、针对高应力全煤巷道围岩特性，，结合煤巷变形破坏特征，提出全断面锚杆索包络圈支护技术，其巷道围岩完整性得到改善，巷道围岩支护结构的承载能力得到提高；分析表明煤体原位力学性质、巷道围岩支护参数及联合支护形式的合理选择直接决定高应力全煤巷道围岩的稳定控制。 3、针对高应力全煤巷道围岩稳定性控制，采用全断面锚杆（索）联合支护方式，高应力作用下的全煤巷道围岩仅发生较小的变形破坏，随着载荷的不断增大，全煤巷道最终能保持一个良好的稳定状态，全煤巷道围岩应力、变形基本上得到较为完善的控制，全断面锚杆（索）联合支护方式改善煤巷变形破坏效果较为显著。 4、模拟试验研究表明，将改进方案与原方案普通锚杆索支护相比，采用全断面锚杆（索）联合支护方式使得高应力全煤巷道围岩变形得以有限控制，其中包括顶底板移近量、两帮相向移近量等方面。相似模拟分析可知，采用改进方案与原支护方案相比，高应力全煤巷道帮部相向移近量减小了42.6%，顶底板相对收缩量减小了63.4%，巷道断面收缩率减小了42.5%，由此说明针对高应力全煤巷道，采用全断面锚杆索联合支护的方法，大大减小了巷道煤体的移动、变形、破坏，高应力全煤巷道围岩的整体性和稳定性得到了较大程度的改善。数值模拟结果表明，采用全断面锚杆索包络圈联合支护方式对其全断面围岩煤体的支护效果良好，大大提高了高应力全煤巷道围岩的稳定性。 5、在工程应用的同时，对大同某矿6#煤高应力全煤巷道围岩应力与变形进行监测。结果表明：顶底板最大移近量为50.6mm，锚索最大载荷为122.5KN，且巷道断面收缩与顶板支护载荷均在15天以后达到了稳定状态。表明高应力全煤巷道围岩采用全断面锚杆索包络圈联合支护煤巷取得了良好的应用效果。
[Abstract]:Taking the transportation roadway of No.6 coal mining face in Datong coal mine as the engineering background, combined with the deformation and failure characteristics of surrounding rock of high-stress Full-coal roadway, the theory of full-section bolt-cable support envelope circle, the supporting parameters and methods of high-stress Full-coal roadway surrounding rock, the influencing factors of high-stress Full-coal roadway surrounding rock stability control technology are comprehensively studied in this paper. In-situ mechanical properties test and measurement of coal body, similar simulation of surrounding rock support in high stress coal roadway, numerical simulation, engineering application and other methods are carried out to study the supporting parameters of surrounding rock stability control in high stress coal roadway and its combined support scheme. The stability of surrounding rock in high stress coal roadway is monitored and studied in engineering construction. The following conclusions can be drawn:
1. The surrounding rock of deep-buried high-stress all-coal roadway has low in-situ mechanical strength and poor self-stability under the influence of high geostress and rheological effect of soft rock coal. Under the action of high geostress, the surrounding rock of roadway is easy to collapse and fall. It is very difficult to maintain the stability of surrounding rock of high-stress all-coal roadway. The uniaxial compression test was carried out on the surrounding rock samples of the Full-coal roadway in No.6 coal mining face. The mechanical properties of the surrounding rock of the roadway are mainly rheological and plastic. This is the basic reason for the large deformation and fast deformation rate of the surrounding rock in the initial stage of roadway driving.
2. According to the characteristics of surrounding rock of high-stress coal roadway and combined with the deformation and failure characteristics of coal roadway, the full-section bolt-cable enveloping ring supporting technology is put forward. The integrity of surrounding rock of roadway is improved and the bearing capacity of supporting structure of surrounding rock of roadway is improved. Rational selection directly determines the stability control of surrounding rock of high stress full coal roadway.
3. In view of the stability control of surrounding rock of high stress coal roadway, the whole section bolt (cable) combined support method is adopted. Under the high stress, the surrounding rock of the whole coal roadway only occurs small deformation and failure. With the increasing load, the whole coal roadway can maintain a good stable state eventually. The stress and deformation of the surrounding rock of the whole coal roadway are basically better. In order to improve the control, the whole section bolt (cable) combined support method is more effective in improving the deformation and failure of the coal roadway.
4. The simulation test shows that the deformation of surrounding rock of high stress full-seam roadway can be limited controlled by the combined support of full-section bolts and cables, including the displacement of roof and floor and the displacement of two sides. Compared with the protection scheme, the displacement near the roadway side is reduced by 42.6%, the relative shrinkage of roof and floor is reduced by 63.4%, and the section shrinkage is reduced by 42.5%. This shows that the method of bolt-cable combined support for high-stress coal roadway greatly reduces the movement, deformation, damage and high-stress coal mass. The numerical simulation results show that the combined support of full-section bolt-cable enveloping ring has a good supporting effect on the full-section surrounding rock, and greatly improves the stability of the surrounding rock of high-stress Full-coal roadway.
5. At the same time of Engineering application, the stress and deformation of surrounding rock of 6# coal roadway in Datong are monitored. The results show that the maximum displacement of roof and floor is 50.6 mm, the maximum load of anchor cable is 122.5 KN, and the shrinkage of roadway section and the load of roof support are stable after 15 days. Combined application of full section anchor bolt and enveloping ring to support coal roadway has achieved good application results.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353

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