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虚心旋转综放工作面矿压分布特征分析

Analysis on the distribution characteristics of underground pressure in the fully

  • 摘要: 旋转综放工作面覆岩运动规律因受采空区形状及工作面侧向约束条件等因素的影响,同一工作面不同区域或不同开采阶段的矿压显现程度各有特点。考虑旋转开采期间割煤工艺和调斜开采可能对其采场矿压显现造成的影响,针对旋转综放工作面不同区域的顶板结构及其顶板压力分布情况等问题,以长春兴煤矿301综放工作面为工程背景,根据其开采条件及其上覆岩层的岩石力学特性,在推算出旋转开采期间工作面不同区域顶板结构模型的基础上,采用理论分析、数值模拟和现场实测的方法,对工作面旋转区的顶板压力分布特征与正常回采期间存在显著差异的现象进行了分析。研究表明:转采期间,由于机头推进速度远大于机尾,导致同一时期内沿工作面走向和倾向上各处的回采空间体积及采动影响范围差别较大;同时在机头区的三角弧形顶板影响范围内,随着转采步距的增加,距旋转中心越远的区域,弧形板悬顶面积就越大,加上覆岩采动影响范围内存在一层较厚的顶板可起到侧向传递力的作用,这3个条件共同作用的结果是采动空间较小处机头区的顶板压力比采动空间较大处的顶板压力明显增大,引起机头区的应力集中。

     

    Abstract: Due to the influence of gob shape, lateral constraint conditions of working face and other factors, the overburden movement law of the rotary fully-mechanized caving face has its own characteristics in different areas of the same working face or in different mining stages. Considering the influence of coal cutting technology and inclining mining during rotary mining on the ground pressure appearance of the stope, aiming at the roof structure and roof pressure distribution in different areas of the rotary fully-mechanized caving face, this paper takes the 301 fully-mechanized caving face of Changchunxing coal mine as the engineering background, according to its mining conditions and the rock mechanical properties of the overlying strata, based on the calculation of roof structure model in different areas of working face during rotatary mining, and uses the methods of theoretical analysis, numerical simulation and field measurement, the significant difference between the roof pressure distribution characteristics in the rotating area of the working face and the normal mining period was analyzed. The research results show that during the transfer mining period, the advance speed of the head is much faster than that of the tail, resulting in a large difference in the volume of stoping space and the mining influence range along the strike and dip of the working face in the same period. At the same time, within the influence range of triangular arc-shaped roof in the head area, with the increase of the mining transfer step distance, the farther away from the center of rotation, the larger the area of arc-shaped roof overhang. In addition, a thicker roof layer within the influence scope of overburden mining can play the role of lateral transmission force. As a result of the combined action of these three conditions, the roof pressure in the head area with a small mining space increases obviously compared with that in the area with a large mining space, which causes the stress concentration in the head area.

     

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