深部超长孤岛工作面覆岩垮落结构特征研究

Study on caving structure characteristics of overlying strata in deep super long island working face

为了解决煤矿采深加大、工作面加长后工作面岩层控制的难题,通过理论分析、相似模拟、现场测试及验证,对深部超长孤岛工作面覆岩垮落结构特征及相应的矿压显现规律进行了研究,结果表明;采空区老顶的破断形态与工作面长宽比密切相关,超长工作面条件下老顶往往形成竖向"X"形破坏,并求得了基本顶上方覆岩下沉挠度函数;通过建立相似模型,分析了覆岩垮落形态和下沉曲线与工作面长度的关系,认为随着工作面长度的增加,工作面倾向极易形成砌体梁结构,使得工作面倾向有可能存在两个或多个压力峰值。并以寺家庄矿15106超长孤岛工作面为例,研究得出其工作面中部老顶并非一次性折断,而是在倾向方向分区域折断,工作面存在多个压力峰值的现象,与理论和相似模拟分析相吻合,为研究深部超长工作面覆岩垮落结构特征提供了理论依据。

Aiming at the working face strata control after the coal mining depth is increased and the working face is lengthened, theoretical analysis, similar simulation, field test and verification are carried out to study the structural characteristics of overlying strata caving and the corresponding law of mine pressure in the super long island working face. The result shows that the fracture pattern of the old roof in the goaf is closely related to the aspect ratio of the working face. Under the super long working face condition,the old roof often forms a vertical x-shaped failure,and the deflection function of the overburden subsidence above the basic roof is obtained. By establishing a similar model,the overlying strata caving pattern and subsidence pattern are analyzed. The relationship between the curve and the length of the working face shows that with the increase of the working face length,it is easy to form a masonry beam structure along the dip of the working face,which makes it possible to have two or more pressure peaks along the dip of the working face. Taking the 15106 super long island working face of Sijiazhuang Mine as an example,the field observation shows that the old roof in the middle of the working face,instead of being broken at one time,is broken at different regions. There are many pressure peaks in the working face,which are consistent with the theory and similar simulation analysis. The study can provide a theoretical basis for the study of overlying strata caving structure characteristics of deep super long working face.