摘要
针对工作面开采过程中上覆弱胶结古近系砂砾岩含水层易导致溃水溃砂事故的问题,以西部某矿井21-1煤层开采过程为研究背景,研究确定了安全开采煤层厚度,以降低工作面发生溃水溃砂事故的可能性。利用离散元颗粒流PFC^3D软件构造工作面三维模型,依据工作面现场测得的宏观参数,通过宏细观参数转换公式转换成细观参数导入三维模型中,模拟工作面在开采厚度为2、4、6、8 m时水砂混合物流动的情况,从而分析工作面发生溃水溃砂灾害的可能性。结果表明:从溃水溃砂通道发育过程及含水层水压变化2个角度分析,煤层开采厚度为2、4 m时,溃水溃砂通道没有贯通到工作面,含水层水压还存在一定的压力,此时发生溃水溃砂事故的概率较小,而煤层厚度为6、8 m时,工作面与砂层之间竖向裂隙出现贯通,溃水溃砂通道形成,含水层水压在最终开采阶段逐渐降低至0,工作面发生溃水溃砂等灾害的概率较大,因此选择最优开采煤厚是降低溃水溃砂事故发生可能性的有效措施。研究为相似矿井工作面选取开采煤层厚度与防治溃水溃砂灾害提供理论支持。
In view of the problem of water and sand inrush accidents during the mining of different coal thicknesses in weakly cemented Paleogene sandy conglomerate aquifers,the mining process of a No.21-1 coal seam in a western mine was taken as the research background,and the thickness of the safe coal seam was determined by the study in order to reduce the possibility of water and sand inrush accidents in the working face.The discrete-element particle flow PFC^3D software is used to construct a three-dimensional model of the working surface.Based on the macro parameters measured in the field,the macro-micro parameter conversion formula are converted into the micro-parameters and imported into the three-dimensional model.The simulated thickness of the face is 2,4,6,8 m at the time of water and sand mixture flow,so as to analyze the possibility of water and sand inrush accidents on the working face.The results show that:from the perspective of the development process of the water and sand inrush channels and the change of the water pressure in the aquifer,when the coal seam mining thickness is 2 m and 4 m,the water and sand inrush channels do not reach the working surface,and there is still a certain amount of water pressure in the aquifer.At this time,the probability of water and sand inrush accidents is small.When the thickness of the coal seam is 6 m and 8 m,vertical cracks appear between the working face and the sand layer are penetrated,water and sand inrush channels are formed and the water pressure of the aquifer gradually decreases to zero in the final mining stage.Therefore,there is a high probability of occurrence of disasters such as water and sand inrush in the working face.The research provides theoretical support for the selection of coal seam thickness and the prevention of water and sand inrush hazards in similar mine working faces.
作者
石磊
SHI Lei(China Coal Research Institute,Beijing 100013,China;Xi'an Research Institute,China Coal Technology&Engineering Group Xi'an 710054,China;Shaanxi Key Lab of Mine Water Hazard Prevention and Control,Xi'an 710077,China)
出处
《煤炭科学技术》
CAS
CSCD
北大核心
2020年第7期347-353,共7页
Coal Science and Technology
基金
国家重点研发计划资助项目(2017YFC0804100)
中煤科工集团西安研究院有限公司面上资助项目(2018XAYMS11)。
关键词
弱胶结地层
水砂混合物
PFC3D
溃水溃砂
weakly cemented formation
water-sand mixture
PFC3D
sand and water inrush
