综放工作面回采巷道围岩变形阶段确定方法

为分析综放工作面前方巷道变形特征,以河林煤矿j7401综放工作面为研究对象,采用理论分析和现场实测方法进行深入研究。根据超前支承压力的分布曲线,定义了工作面前方巷道的3个变形阶段,分别为急速变形阶段、减速变形阶段和稳定变形阶段。急速变形阶段和减速变形阶段的分界点是超前支承压力和原岩应力的交点,减速变形阶段和稳定变形阶段的分界点是超前支承压力的峰值点。对j7401工作面开采过程中的超前支承压力和巷道变形分别进行观测,并采用最小二乘拟合方法分析整理观测数据。根据超前支承压力观测数据对巷道围岩变形阶段进行划分,急速变形阶段和减速变形阶段的分界点位于工作面前方8.1m,减速变形阶段和稳定变形阶段的分界点是工作面前方19.8m。根据巷道变形观测数据划分变形阶段,急速变形阶段和减速变形阶段的分界点位于工作面前方8.9m,减速变形阶段和稳定变形阶段的分界点是工作面前方20.1m。该划分方法的两个误差分别为0.8m和0.3m,证明根据超前支承压力划分巷道围岩变形阶段的方法可行,精度较高。

Determination of the deformation stage of a fully mechanized caving face in the surrounding rock of mining roadway

To analyze the deformation characteristics of the mining roadway located in front of the fully mechanized top-coal caving face, we researched the j7401 fully mechanized top-coal caving face of the Helin Coal Mine with theoretical analysis and field measurement. According to the distribution curve of the advanced abutment pressure, three deformation stages of the roadway ahead of the working face are defined, which are the quick deformation stage, the deceleration deformation stage, and the stable deformation stage. The cut-off point of quick deformation stage and deceleration stage is the intersection of advanced abutment pressure and the original rock stress. The cut-off point of the deceleration deformation stage and stable deformation stage is the peak of the advanced abutment pressure. In this work, the advanced abutment pressure and roadway deformation of j7401 working face in mining were observed respectively, and the observation data was analyzed by the method of least squares fitting. The deformation of the roadway surrounding rock was partitioned based on the advanced abutment pressure observation data:the cut-off point of quick deformation stage and deceleration stage was 8.1 m ahead of the working face, and the cut-off point of deceleration deformation phase and stable stage was 19.8 m ahead of the working face. The deformation was also partitioned based on the roadway deformation observation data, in which way the cut-off point of quick deformation stage and deceleration stage was 8.9 m in front of the working face, and the cut-off point of deceleration deformation phase and stable stage was 20.1 m ahead of the working face. The deviations of the two classification methods were respectively 0.8 m and 0.3 m, indicating the method to partition the roadway surrounding rock deformation stage based on the advanced abutment pressure observation data is feasible and the precision is high.