摘要
为了研究综采工作面卸压瓦斯覆岩裂隙优势通道的演化规律,以采动裂隙椭抛带理论为基础,工作面推进速度为关键参数,构建采动卸压瓦斯优势通道数学模型,并针对山西和顺某高瓦斯矿井主采工作面,开展综采工作面在不同推进速度条件下的卸压瓦斯覆岩裂隙优势通道演化规律物理相似模拟试验。研究结果表明:加快推进速度,三带高度降低,平均来压步距增大,优势通道在上覆岩层的空间位置也随之降低,优势通道发育的高度、宽度、垮落角和范围随着推进速度加快而减小。随着推进速度的加快,优势通道离层率和贯通度逐渐变小。随着工作面的推进,优势通道的分形维数由小到大对应的推进速度依次为7、5、3 m/d,呈现出降维的趋势。在现场高位钻孔试验中,对工作面推进速度不同时的高位钻孔参数进行优化调整,得到高位钻场抽采瓦斯占绝对瓦斯涌出总量的49.94%~89.88%,并且使得上隅角及回风巷平均瓦斯体积分数维持在0.27%以下及0.32%以下,从而保证工作面安全高效的回采。研究结果可为不同推进速度下采动覆岩卸压瓦斯富集区的识别提供一定的理论基础。
In order to study the evolution law of the dominant channel in the overburden fractures of the pressure released gas for the fullymechanized coal mining face,with the elliptic paraboloid zone theory of the mining fractures as the base,the advancing speed of fully-mechanized coal mining face was the key parameter. A mathematical model of the dominant channel for the mining pressure released gas was established. According to the main coal mining face in a high gassy mine of Shanxi Heshun area,a physical similarity simulation test was conducted on the evolution law of the dominant channels in the overburden fractures of the pressure released gas under the different advancing speed of fully mechanized coal mining face. The study results showed that with the advancing speed accelerated,the height of the three zones reduced and the average roof weight step distance increased,the dominant channel in the space location of the overburden strata would be decreased. The height,width,caving angle and scope of the dominant channel development would be reduced with the advancing speed increased. With the advancing speed accelerated,the separation rate and penetration of the dominant channel would be steadily reduced. With the continuous forward advancing of the coal mining face,the fractal dimensions of the dominant channel would get bigger gradually under the advancing rate 7、5、3 m/d and would be in a tendency of the dimension reduction. In the test of the site high level drilling,when the coal mining face with different advancing speed,an optimized adjustment was conducted on the parameters of the high level boreholes. The gas drained from the high level drilling site was taken 49.94% ~ 89.88% of the absolute gas emission. Thus the average gas volume fraction from the upper corner and the air return gateway was kept below 0.27% or 0.32% and the safety and high efficient mining of the coal mining face was ensured. The study results could provide a certain theoretical basis to identify the pressure released gas enrichment
作者
赵鹏翔
卓日升
李树刚
林海飞
刘超
双海清
ZHAO Pengxiang;ZHUO Risheng;LI Shugang;LIN Haifei;LIU Chao;SHUANG Haiqing(,School of Safety Science and Engineering,Xi＇ an University of Science and Technology,Xi＇ an 710054,China;MOE Key Lab of Mining and Disaster Prevention in Western Mine,Xi＇ an 710054,China)
出处
《煤炭科学技术》
CAS
北大核心
2018年第7期99-108,共10页
Coal Science and Technology
基金
国家自然科学基金青年科学基金资助项目(51604219)
国家自然科学基金重点资助项目(51734007)
国家自然科学基金面上基金资助项目(51674192
51674189)
关键词
采动覆岩裂隙
优势通道
工作面推进速度
高位钻孔
mining overburden fractures
dominant channel
advancing speed of fully-mechanized coal mining face
high level borehole
