基于散体相似材料模拟的综放开采初始放煤特性研究

Characteristics of initial coal drawing in fully mechanized top coal caving based on similar simulation with granular material

综放开采过程中,由于顶煤移动边界的影响,初始与周期放煤特性不尽相同,准确描述初始放煤特性对提高顶煤回收率,优化放煤工艺参数有着重要意义。以王家岭煤矿12309工作面为背景,运用理论分析、现场实测及相似模拟试验相结合的方法,对综放工作面顶煤的初始放出特征及规律进行了研究。结果表明:将顶煤等效直径分为0~9cm、9~18cm、18~27cm、27~36cm四个区间,每个区间顶煤块体质量分数分别为13.83%、46.31%、20.34%、27.36%;相似模拟试验求出的放出体左右两侧的重力加速度修正系数分别为1/108、1/92,将系数引入到改进B-R模型后计算得出12309工作面的初始放煤时间为33.95s,与实测放煤时间的误差仅为7.74%,可准确描述顶煤的放出特征。

In the process of fully mechanized caving mining,the initial and periodic caving characteristics are different due to the influence of top-coal moving boundary.Taking the 12309 working face of Wangjialing Coal Mine as the background,the initial drawing characteristics and laws of top coal in fully mechanized caving face are studied by combining theoretical analysis,field measurement and physical simulation test.The results show that:the equivalent diameter of the top coal is divided into four sections:0~9cm,9~18cm,18~27cm and 27~36cm.The mass fraction of the top coal in each section is 13.83%,46.31%,20.34%,and 27.36%,respectively.According to the similar simulation experiment,the correction coefficients of gravity acceleration on the left and right sides of the drawn-out body are 1/108 and 1/92 respectively.After introducing the coefficient into the improved B-R model,it is calculated that the drawing time of 20309 working face is 33.95s,and the error with the measured drawing time is only 7.74%,which can accurately describe the drawing characteristics of top coal.