近距重复采动无墙体沿空留巷围岩稳定与控制技术

发布时间：2018-04-17 02:19

本文选题：近距离煤层 + 重复懫动　；参考：《中国矿业大学》2015年硕士论文

【摘要】：老母坡煤矿2煤、3煤层间距6~12m,埋深较浅,无瓦斯隐患,为解决工作面接续紧张、资源采出率低等难题,进行了近距煤层重复采动条件下得无充填墙体沿空留巷。目前对于单一煤层开采条件下沿空留巷围岩控制技术研究较多,但对于近距重复懫动下无充填沿空留巷围岩控制理论的研究较少。本文综合采用理论分析、数值模拟与现场实测等方法,从上覆煤层懫后下伏煤层的矿压显现规律以及底板损伤范围入手,分析了下伏采空区下留巷顶板结构及其荷载特征,提出了重复懫动无墙体沿空留巷切顶力学模型,阐明了留巷侧向基本顶的断裂平衡机制,结合“给定载荷”、“给定变形”、“采空区矸石侧压”以及“底板比压”,设计了巷旁强力切顶支架作为巷旁支护方式,完善了近距煤层重复懫动无墙体沿空留巷围岩控制体系。主要研究成果如下:(1)运用弹塑性理论,结合上覆煤层顶板垮落特点及其应力分布推导得出上覆煤层懫后底板损伤破坏深度,并通过数值模拟及现场RQD质量指标实测进行验证;通过底板屈服比计算及老母坡矿实际地质条件,确定老母坡煤矿下伏巷道顶板存在单层基本顶,为下伏3煤顶板锚索长度的确定提供了初步依据。(2)以老母坡煤矿地质条件为例,通过数值模拟,揭示近距下伏煤层工作面矿压显现规律,为探讨近距下伏煤层无墙体沿空留巷围岩控制提供可靠的理论基础。(3)针对近距离煤层懫后顶板特征,理论研究了近距离下伏煤层沿空留巷顶板荷载的计算依据,分析了上覆煤层懫后下伏沿空留巷侧向基本顶的破断失稳特征。(4)通过对国内无墙体沿空留巷的成功案例进行归纳总结,分析了无墙体沿空留巷的适用条件;依据无墙体沿空留巷切顶力学模型,结合“给定载荷”、“给定变形”、“采空区矸石侧压”等分析了巷旁切顶支架载荷的设计依据;通过数值模拟计算,分析了巷旁400k N/m、600k N/m、800k N/m以及1000k N/m四种切顶载荷下留巷基本顶的破断形态及其对沿空留巷围岩应力分布及位移的影响情况;通过模拟分析巷内1排、2排及3排单体支护时,留巷顶板及实体煤支承压力及围岩变形情况,确定合理的巷内辅助单体支撑密度。(5)针对近距下伏煤层顶板受上覆煤层采动损伤影响,沿空留巷顶板破碎易冒顶等安全隐患问题,采用现场试验的方法确定了包括掘进期间锚杆的施工预紧力矩、合理的锚索支护长度以及留巷期间的巷旁强力切顶支架切顶、顶板深浅孔联合注浆加固技术、防漏风隔模和喷涂材料喷涂封闭采空区等安全保障体系,形成了一套较为完善的近距重复懫动无墙体沿空留巷技术,在取消巷旁充填墙体的条件下,保证了留巷的成功。老母坡煤矿近距重复懫动无墙体沿空留巷的成功实施,为重复采动下的沿空留巷开辟了一条新的路径,其实践过程中积累的技术和现场管理经验具有较高的推广价值。
[Abstract]:In Laomupo Coal Mine, the distance between 2 and 3 coal seams is 612m, the depth is shallow and there is no gas hidden danger. In order to solve the problems such as the tension of the working face and the low recovery rate of the resources, the roadway along the goaf of the wall without filling is carried out under the condition of repeated mining in the short distance coal seam.At present, there are many researches on the surrounding rock control technology of gob-side roadway under the condition of single coal seam mining, but there is little research on the control theory of surrounding rock without filling along gob-side roadway under short-distance repeated movement.In this paper, theoretical analysis, numerical simulation and field measurement are used to analyze the roof structure and load characteristics of underground roadway in underside goaf, starting with the law of rock pressure behavior and the damage range of floor in overlying coal seam.In this paper, a mechanical model of cutting roof along goaf retaining roadway with repeated wall is put forward, and the fracture equilibrium mechanism of lateral basic roof of retaining roadway is expounded. Combined with "given load", "given deformation", "side pressure of gangue in goaf" and "specific pressure of bottom plate",The strong roof cutting support beside the roadway is designed as the roadside support, and the control system of the surrounding rock along the gob retaining roadway is improved.The main research results are as follows: (1) based on the elastoplastic theory, combined with the characteristics of roof caving and its stress distribution, the damage and failure depth of overlying coal seam is obtained, which is verified by numerical simulation and field RQD quality measurement.Based on the calculation of floor yield ratio and the actual geological conditions of Laomupo Coal Mine, it is determined that there is a single layer basic roof in Laomupo Coal Mine, which provides a preliminary basis for the determination of the length of anchor cable for the roof of No. 3 coal mine.) the geological conditions of Laomupo coal mine are taken as an example.Through numerical simulation, the paper reveals the regularity of rock pressure in coal face, which provides a reliable theoretical basis for the control of wall rock of roadway left along goaf without wall wall in short distance coal seam, and aims at the characteristics of roof in short distance coal seam.In this paper, the calculation basis of roof load along goaf roadway in short distance coal seam is studied theoretically.Based on the analysis of the failure and instability characteristics of the lateral basic roof of the overlying coal seam, the author summarizes the successful cases of the roadway left along the gob without wall in China, and analyzes the applicable conditions of the roadway left along the gob without wall.According to the mechanical model of roof cutting along goaf retaining roadway without wall, combined with "given load", "given deformation" and "side pressure of gangue in goaf", the design basis of roof cutting support load by roadway side is analyzed.In this paper, the fracture morphology of the basic roof and its influence on the stress distribution and displacement of the surrounding rock along the goaf are analyzed under four cutting loads of 400K N / m 600k N / m and 1000K N / m beside the roadway, and the single support of 1 row, 2 row and 3 rows in the roadway is analyzed by simulation.The supporting pressure of roof and solid coal and the deformation of surrounding rock are determined, and the reasonable supporting density of auxiliary monomer in roadway is determined. Aiming at the safety hidden trouble, such as roof breakage and roof falling along goaf, the roof of coal seam in short distance is affected by mining damage of overlying coal seam, and the roof of roadway along goaf is broken and easy to fall.The method of field test is used to determine the construction pretightening moment of anchor rod during excavation, the reasonable length of anchor cable support, the roof cutting technology of strong roof cutting support and the combined grouting reinforcement technology of roof deep and shallow hole during roadway stay.The safety guarantee system, such as air leakage proof mould and sprayed material spraying closed goaf, has formed a set of relatively perfect technology of keeping roadway along the goaf without wall moving in short distance, and the success of retaining roadway can be ensured under the condition of canceling the wall filling beside the roadway.In Laomupo Coal Mine, the successful implementation of the short distance and repeated movement without wall along the gob-side roadway opens a new path for the gob-side roadway under repeated mining, and the accumulated technology and field management experience in the process of practice are of high popularizing value.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353

【参考文献】