巷道设计在很大程度上是支护设计,而围岩松动圈作为支护设计的依据,进行现场实测是最可靠的方法.采用地质雷达对榆树岭煤矿进行松动圈测试,探究巷道跨度、采动应力等因素对围岩松动圈的影响.测试与分析结果表明:下5煤层巷道全断面松动圈均小于2.0 m,为中等松动圈,而水平应力远大于垂直应力是顶板松动圈大于两帮松动圈的原因;巷道跨度对围岩松动圈的影响并不显著,在5.0～11.5 m跨度范围内,松动圈增幅5％～15％,因此4～8 m 跨度范围内巷道采用相同支护方案时,可优化锚杆与锚索预紧力来保证巷道稳定;沿空掘巷一次采动影响后,全断面松动圈均超过2.0 m,松动圈增幅15％～22％,可作为沿空掘巷煤柱留设宽度的依据;围岩松动圈范围内的破碎区较易识别,而裂隙区的判断则需要结合经验或2种以上测试方法进行综合分析判断.
Test and Analysis on the Influence of Roadway Span and Mining Stress on Loose Circle of Surrounding Rock
Roadway design is heavily centered around support design.As the basis for the support design,field measurement of the surrounding rock loose circle is the most reliable meth-od.This study used geological radar to explore the influence of factors such as roadway span and mining stress on the loose circle of surrounding rock in Yushuling Coal Mine.The test and analy-sis results show that:The loose circles of the full-face roadway in the lower-5 coal seam are less than 2.0 m,which is a medium loose circle.Its horizontal stress is much larger than its vertical stress,which is the reason why the loose circle of the roof is larger than that of the two sides.The influence of the roadway span on the loose circle of the surrounding rock is not significant:within the span range of 5.0 to 11.5 m,the loose circle increased by 5％to 15％.Therefore,in the range of 4 to 8 m span,when the roadway adopted the same support scheme,the preload of anchor rods and anchor cables could be optimized to ensure the roadway stability.After the first mining along the gob,the loose circle of full-face roadway exceeded 2.0 m,and the loose circle increased by 15％to 22％,which could be used as the basis for determining the width of coal pil-lars along the gob.It is easier to identify the fracture zone within the loose circle of surrounding rock,while determining the crack area requires the comprehensive analysis and judgment based on experience or more than two testing methods.
surrounding rock loose circleroadway spanmining stressgeological radar testfracture zone and crack area
万方数据
维普
