综放仰采工作面覆岩移动规律及支架工作阻力确定

Movement law of overburden in upward fully mechanized working face and determination of support working resistance

综放仰采工作面覆岩运移规律与水平开采工作面有较大差别,顶板垮落频繁,为工作面支架的稳定带来了极大的考验。现有对综放仰采工作面安全开采的研究主要集中在仰采角度变化对覆岩运移规律的影响上,对顶底板受力特征缺乏系统的研究。针对以上问题,以瑞隆矿8102综放仰采工作面为背景,采用UDEC数值模拟软件分析了综放仰采工作面不同推进距离下覆岩运移规律及顶板破断特征:在仰斜开采中,受倾角和开采方式的影响,底煤应力最为集中,工作面具有明显的初次来压和周期来压特征,与近水平煤层综放工作面相比,周期来压步距明显减小,上覆岩层峰值强度相对较低,顶板不易形成结构,来压较频繁,矿压显现较剧烈;8102工作面直接顶初次垮落步距为25 m,基本顶初次来压步距为40 m,周期来压步距为10~15 m。利用顶板-支架力学关系确定支架工作阻力的计算方法较为繁琐,很多方法应用于工程现场不具有实用性,对比了目前几种常用支架工作阻力计算方法的优缺点及实用性,并根据8102工作面实际工况确定了动载荷计算法为最适合的支架工作阻力计算方法,具有计算结果精确且参数容易选取的特点,确定了该工作面的支架最大工作阻力为6359 kN/架,工作阻力大于7066 kN的支架即可满足该工作面支撑要求。工程应用结果证明了利用动载荷计算法计算8102工作面支架工作阻力的正确性。

The overburden movement law of the upward fully mechanized working face is different from that of the horizontal working face.The roof collapses frequently,which brings a great test to the stability of the working face support.The existing research on the safe mining of the upward fully mechanized working face mainly focuses on the influence of the change of the mining angle on the overburden movement law,and there is a lack of systematic research on the force characteristics of the roof and floor.In order to solve the above problems,taking the 8102 upward fully mechanized working face in Ruilong Mine as the background,the UDEC numerical simulation software is used to analyze the overburden movement law and roof fracture characteristics at different advancing distances of the upward fully mechanized working face.In the upward working face,affected by the inclination angle and mining method,the bottom coal stress is most concentrated,and the working face has obvious characteristics of initial pressure and periodic pressure.Compared with the nearly horizontal fully mechanized working face,the periodic pressure step is obviously reduced,the peak strength of the overburden is relatively low,the roof is not easy to form a structure,the pressure is more frequent,and the mine pressure appears more intense.The step distance of the first collapse of the direct roof of 8102 working face is 25 m,the step distance of the initial pressure of the basic roof is 40 m,and the step distance of the periodic pressure is 10-15 m.The existing calculation methods of using the roof-support mechanical relationship to determine the working resistance of support are relatively cumbersome.Many methods are not practical when applied to the engineering site.By comparing the advantages,disadvantages and practicality of several commonly used support working resistance calculation methods,it is concluded that the dynamic load calculation method is the most suitable method for calculating the working resistance of the support according to the actual working conditions of 8102 working face.The method has the characteristics of accurate calculation results and easy selection of parameters.It is determined that the maximum working resistance of the support of this working face is 6359 kN/frame,and the support of this working face with a working resistance greater than 7066 kN can meet the support requirements.The results of engineering application have proved the correctness of using dynamic load calculation method to calculate the working resistance of the support of 8102 working face.