大倾角变角度综放工作面覆岩运移规律分析及应用

发布时间：2018-09-19 15:48

【摘要】：大倾角变角度工作面顶板破坏与运移规律特殊,变角段“支架—围岩”系统稳定性控制难度大。本文以枣泉煤矿大倾角变角度120210综放工作面为研究背景,通过现场观测、物理相似材料模拟实验和数值计算实验相结合的手段,运用已有的大倾角煤层开采理论,系统研究了大倾角变角度工作面特别是变角段处的覆岩运移规律,研究表明:大倾角变角度煤层覆岩垮落具有明显的时序性和不均匀性,以变角段为界工作面顶板的应力场分布、破坏场分布、采空区充填特征以及支架工作阻力分布均出现了不同于单一倾角煤层的规律与特点。变角段应力集中,变形程度高,采空区充填程度低、支架与顶板约束作用差,是工作面覆岩运移特征的关键影响因素;大倾角变角度工作面顶板应力呈“驼峰”状非对称分布形态。上下区段的应力场在变角段出现叠加,造成变角段附近顶板应力集中,变形破坏程度高,拉伸破坏范围增大。上区段及下区段的顶板最大垂直应力随着变角度的增大而降低,但峰值位置不断向变角度处移近,加剧了整个工作面顶板应力分布的非对称性;上区段煤层倾角较小,垮落矸石沿倾斜方向的滑移充填作用不充分,下区段上部和变角段顶板破碎程度高,垮落充分,垮落矸石在重力作用下向下区段发生滑移,呈现下区段充填压实、变角段部分充填、上区段完全充填的特征。同时上区段垮落矸石不能有效对变角段采空区进行补充,该处垮落矸石对顶板的约束作用最弱,上覆岩层运动程度加剧,失稳形式复杂化。枣泉煤矿120210工作面支架受载及稳定性特征验证了大倾角变角度工作面的覆岩运移破坏特征,基于这一特征并结合现场生产实际,枣泉煤矿大倾角变角度工作面依据“上区段为高效生产的主体,下区段是实现安全的基础,变角段是上下区段转换的关键”的原则进行生产技术管理,可获得良好的经济与社会效益。
[Abstract]:The rule of roof failure and movement is special in large angle and variable angle working face, so it is difficult to control the stability of "support-surrounding rock" system in variable angle section. In this paper, based on the research background of 120210 fully mechanized caving face with large dip angle and variable angle in Zaoquan Coal Mine, by means of field observation, physical similar material simulation experiment and numerical calculation experiment, the existing mining theory of large dip angle coal seam is used. In this paper, the overlying rock migration law of large dip angle variable angle working face, especially at variable angle section, is systematically studied. The study shows that the overburden rock collapse of large dip angle variable angle coal seam has obvious time series and inhomogeneity. The distribution of stress field, failure field, filling characteristics of goaf and working resistance distribution of support are different from that of single dip coal seam. Stress concentration, high degree of deformation, low degree of filling in goaf and poor constraint between support and roof are the key factors affecting the characteristics of overlying rock movement in the working face. The roof stress of the working face with large dip angle varied in the form of "hump" asymmetrical distribution. The stress field of the upper and lower section is superposed in the variable angle section, which results in the stress concentration of roof near the variable angle section, the high degree of deformation and failure, and the extension of tensile failure range. The maximum vertical stress of roof in the upper and lower sections decreases with the increasing of the angle, but the peak position moves closer to the variable angle, which intensifies the asymmetry of the distribution of the roof stress in the whole working face, and the inclined angle of the coal seam in the upper section is small. The slippage and filling of the caving gangue along the inclined direction is not sufficient, the upper part of the lower section and the variable angle section have a high degree of breaking and falling, and the caving gangue slips down the section under the action of gravity, which shows that the next section is filled with compaction. The characteristic of partial filling in the variable angle segment and complete filling in the upper section. At the same time, the caving gangue in the upper section can not effectively supplement the goaf of the variable angle section, where the caving gangue has the weakest constraint on the roof, the movement degree of the overlying rock is intensified, and the form of instability is complicated. The characteristics of bearing load and stability of 120210 working face in Zaoquan Coal Mine verify the characteristics of overburden movement and failure in the face with large dip angle and variable angle. Based on this characteristic and combined with the field production practice, According to the principle that "the upper section is the main body of high efficiency production, the lower section is the basis for realizing safety, and the variable angle section is the key to the conversion of the upper and lower sections", the production technology management is carried out. Good economic and social benefits can be obtained.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD325

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