低应力软岩复合顶板大变形煤巷支护技术

 低应力软岩复合顶板煤巷,虽然埋深较浅,围岩自重应力水平不高,但因顶底板岩层岩性及结构的特殊性,巷道围岩具有软岩的特性。以黑沟煤业有限公司主采4-2煤层回采巷道为工程背景,对该地质条件下巷道支护技术进行研究,结果表示,锚杆支护产生的夹持作用可提高巷道浅部围岩完整程度及深部围岩承载能力,缩小浅部围岩的破坏范围;锚索支护能够提高深部围岩与浅部围岩的整体性,减缓围岩的整体沉降运动趋势;金属网与钢带可加强对表面围岩的约束作用,限制破坏区向深部发展和表面围岩的冒落变形,减小顶板岩层的变形;底角锚杆能够促使应力峰值向深部的转移,减轻垂直应力向水平应力的转化程度,控制巷道底臌变形。上述支护方式的综合运用,可实现复合软岩大变形煤巷的有效支护。

Support Technology for the Low Stress and Soft Strata Composite Roof with High Deformation Roadway

The surrounding rock stress level of low-stress composite soft strata roadway is lower for the shallow depth; however it displays soft rock characteristics for its unique lithology and structure of roof and floor. The roadway support techniques for such kind of geological conditions are researched with the background of Heigou Coal Co., Ltd. four-two coal seam. Clamping action produced by bolting support is able to not only increase the completeness of shallow rock and bearing capacity of deep rock, but also reduce the failure range of shallow rock; cable support could increase the integrity of shallow and deep rock, slowing the overall sedimentation trends of surrounding rock; metal mesh and steel belt could enhance the restraint action to surface adjoining rock, limit failure zone development towards depth and deformation of surface rock and roof strata; corner bolt induce peak stress shift to the depth, reduce the conversion level of vertical stress to horizontal stress, and control the roadway floor heave deformation. The composite applications of support methods mentioned above are able to achieve the valid effect of composite soft strata with high deformation roadway.