基于有效锚固层厚度的近距离煤层下伏巷道支护技术数值模拟研究

Numerical simulation study on support technology for underlying roadways of close distancecoal seams based on effective anchor layer thickness

针对近距离煤层下伏巷道围岩破碎、锚杆(索)支护控制难度大等问题,以任楼煤矿Ⅱ7_324S工作面回风巷为工程背景,通过理论分析和现场测试,计算了上覆7_2煤层开采后底板岩层破坏深度,分析了下伏7_324S回风巷顶板损伤特征及锚杆(索)可锚性。基于此,根据间隔层厚度对Ⅱ7_324S工作面回风巷进行了分区;基于顶板叠加梁支护理论,提出了Ⅱ7_324S工作面回风巷分区域锚杆(索)支护技术方案,并采用有效锚固层厚度指标,对各区域支护方案进行了校核,确定7_324S工作面回风巷各区域顶板处于有效锚固状态,并对其进行了数值模拟。结果表明,下伏煤巷分区域支护技术具备实际工程生产实践的可行性。

In response to the problems of surrounding rock fragmentation and difficulty in controlling anchor bolt(cable)support in the surrounding rock of the underlying roadways of close distance coal seams,taking the ventilation roadway of theⅡ7324S working face of Renlou Coal Mine as the engineering background,through theoretical analysis and on-site testing,the depth of damage to the floor rock layer after mining the overlying 72 coal seam was calculated,and the characteristics of damage to the roof of the underlying 7324S ventilation roadway and the anchoring ability of the anchor bolt(cable)were analyzed.Based on this,the ventilation roadways of theⅡ7324S working face were divided according to the thickness of the interlayer.Based on the theory of roof superimposed beam support,a regional anchor bolt(cable)support technology scheme for the ventilation roadway of theⅡ7324S working face was proposed.The effective anchor layer thickness index was used to verify the support schemes for each region.The roof of each area of the ventilation tunnel in theⅡ7324S working face was determined to be in an effective anchoring state,and numerical simulation was conducted.The results showed that the regional support technology for the underlying coal roadway has the feasibility of practical engineering production.