厚煤层大断面巷道支护技术研究

Study on support technology of large cross section gateway in thick seam

为了研究厚顶煤大断面巷道掘进过程中的巷道围岩破坏情况及合理支护方式,采用数值模拟和井下试验方法分析了不同巷道宽度下巷道围岩的变形破坏情况及不同支护方式对巷道围岩稳定性的影响,研究结果表明:巷道宽度变化对厚煤层顶板稳定性影响较大,巷道宽度由4 m增加到6 m时,顶板沉降量增加了55 mm,最大变形出现在厚煤层顶板中部,采取高预应力锚杆索支护方式并适当提高顶板支护密度,可以对浅部围岩施加更大压应力,进而更好地控制顶板沉降,井下工程实践表明:合理的锚杆索预紧力及支护参数可保持巷道围岩结构稳定性,矿压监测数据显示,两帮变形最大均未超过40 mm,顶板最大离层值未超过100 mm,锚杆、锚索受力始终保持稳定,支护效果良好。

In order to study the failure condition of the gateway surrounding rock in the driving process of the large cross section gateway with thick top seam and the rational support method,a numerical simulation and an underground test method were applied to analyze the deformation failure condition of the gateway surrounding rock under different width of the gateway and the different support method affected to the stability of the gateway surrounding rock.The study results showed that the width variation of the gateway would have a big influence to the stability of the thick seam roof.When the width of the gateway was increased from 4 m to 6 m,the roof subsidence would be increased with 55 mm.The max deformation would be occurred in the middle of the thick seam roof.The application of the pre-stressed bolt and anchor support method and a proper improvement of roof support density could make a higher pressure stress to the surrounding rock in the shallow depth and could well control the roof subsidence.The underground engineering practices showed that the rational pretension and the support parameters of the bolt and anchor could keep the stability of the gateway surrounding structure.The mine pressure monitoring and measuring data showed that the max deformation of the two sidewalls both would not be over 40 mm,the max bed separation value of the roof would not be over 100 mm,the bolt and anchor stressed would keep stable and the support effect was excellent.