煤矿工作面推采采空区涌水双指数动态衰减动力学研究

Double-exponential variation law of water-inflow from roof aquifer in goaf of working face with mining process

基于系统动力学理论,提出了煤矿工作面推采采空区涌水双指数衰减动力学模型,选取宁东煤田鸳鸯湖矿区典型工作面推采顶板涌水过程为研究对象,进行了双指数动力衰减模型拟合,利用麦克劳林公式等方法确定了具有物理意义的模型参数的近似解,以及工作面推采过程采空区峰值水量及发生位置,动态平衡水量及发生位置,探讨了主要参数的影响因素。结果指示:以动、静两种形态涌入采空区的水量共同作用,控制采空区涌水变化特征,但动态补给量是主控因素;在顶板含水层特征类似,构造影响可忽略条件下,推采速度决定了峰值水量和动态平衡水量发生位置,峰值水量和动态平衡水量受采厚、顶板岩性特征、含水层特征等条件共同影响。研究结果为形成趋势合理、精度较高的工作面涌水量预测方法提供了新思路。

The roof aquifer will be destroyed by the extraction of coal working face,and affects the mining safety conversely.Based on the system dynamics theory,the authors proposed a double-exponential decay model to describe the water-inflow process of roof aquifer with the working face extraction.The authors tested the hypothesis that the process would exhibit spatial variation using typical coal faces with different mining rates in Yuanyanghu mine area,Ningdong coal field.As mining duration increased,the water-inflow process increased trend initially,until reached a peak value,and finally decreased to a equilibrium value with the certain advancing lengths of the coal faces.The approximate solution of model parameters with physical meaning was determined by McLaughlin formula,as well as the water-inflow with peak value and equilibrium value,and their occurring location.The results indicated that the characteristics of water-inflow process were controlled by the dynamic and static inflows,and the dynamic recharge was the main controlling factor.When the condition that the roof aquifer was similar and the tectonic influence was negligible,the mining rate determined the occurring location of the water-inflow with peak value and equilibrium value,while the peak value and equilibrium value were affected by the mining thickness,lithologic characteristics of the roof and the characteristics of the aquifer.The conclusion provides a new way for predicting the water-inflow of working face with reasonable trend and high precision.