考虑倾角与开度的薄基岩裂隙溃沙特性研究

Study of characteristics of collapsing-sand considering angle and fracture opening in thin bedrocks

顶板溃沙是我国西部矿区浅埋煤层开采过程中面临的安全威胁之一。利用自行研制的裂隙溃沙试验系统,开展无水条件下风积沙溃沙过程的模拟试验,研究沙层厚度、裂隙倾角和裂隙开度对溃沙速率的影响,获得不同影响因素与裂隙中风积沙流动速率之间的定量关系。研究发现,沙层厚度的变化对溃沙速率几乎没有影响;裂隙倾角的变化对溃沙速率有明显的影响,在裂隙开度一定的情况下溃沙速率随着裂隙倾角的增大而增大,两者之间呈对数关系;裂隙开度对溃沙速率的影响较为显著,裂隙倾角一定时溃沙速率随着裂隙开度的增大而快速递增,两者之间符合指数关系;裂隙开度对溃沙速率的影响权重最大,而沙层厚度的影响权重可以忽略。该研究成果可为西部煤矿溃沙灾害的防治提供理论依据和科学指导。

Roof sand inrush is one of the safety threats faced by mining in shallow coal seam in Western China. By using the self-developed test system of fracture sand inrush, the simulation test of sand inrush process of aeolian sand under the condition of no water are carried out in this paper. The effect of sand layer thickness, fracture angle and crack opening on the rate of sand inrush is studied; and then the quantitative relation between different influence factors and the flow rate of aeolian sand in the fissure is obtained. The research results show that the change of sand layer thickness has little effect on the rate of sand inrush; and the change of the slit angle has an obvious influence on the rate of sand inrush. In the case of a certain crack opening, the rate of sand inrush increases with the increase of the slit inclination, and they are logarithmic relation. When the fracture angle is fixed, the rate of sand inrush increases rapidly with the increase of the crack opening, which is in accordance with the exponential relationship, the crack opening has the greatest influence on the sand inrush rate; and the weight of the sand layer thickness can be ignored. The research results can provide theoretical basis and scientific guidance for prevention and control of sand disasters in coal mines in Western China.