顶板随机裂隙对采动煤岩体支承压力的影响

Numerical simulation of the effects of roof random fractures on abutment pressure of mining working face

基于Monte-Carlo方法利用UDEC中的fish语言编制了离散裂隙网络生成程序,实现了对采动顶板裂隙的模拟.基于某工作面地质条件,采用该程序生成了5种不同发育程度的裂隙数值模型,研究了顶板裂隙发育程度对采动煤岩体支承压力的影响.结果显示:裂隙率和分形维数均能定量描述岩体裂隙的发育特征,顶板的裂隙发育程度对工作面前方支承压力有着显著影响,对于裂隙不发育顶板,支承压力影响范围和支承压力峰值随着采面的推进显著增加,而对于裂隙发育顶板,随工作面推进工作支承压力基本符合周期性显现规律,且支承压力峰值和影响范围相对较小.根据模拟结果提出了支承压力集中系数与裂隙率的关系模型,该模型能够较好的描述支承压力集中系数与裂隙率的关系.

Based on the Monte-Carlo method, a program to generate random fractures in the rockmass was compiled by fish langue in UDEC. The program was used to simulate the random fractures in roof according to the condition of a coal mining face. Five simulation models contai- ning different development characteristics of fracture in roof ware produced. The effects of ran- dom fracture of roof on the abutment pressure of working face were studied. The results show that fraetal dimension and fracture rate can evaluate the rock mass quality quantifieationally, and the development degree of fractures has significant effect on the abutment pressure. When the factures development of roof is poor, the peak and the range of abutment pressure are raised with the advance of working face. When the factures development of roof is great, the appearance of the abutment pressure peak is periodical, and the value and range of abutment pressure is low relatively. According to the results, a model to describe the relation between coefficient of abutment pressure concentration and fracture rate is proposed.