Deformation and failure characteristics of soft rock tunnel surrounding rock under mining and water immersion conditions
解盘石房嘉睿胡博胜张波张希段思宇
XIE Panshi;FANG Jiarui;HU Bosheng;ZHANG Bo;ZHANG Xi;DUAN Siyu
西安科技大学能源学院西部矿井开采及灾害防治教育部重点实验室
在采动影响及淋水浸蚀双重作用下,软岩巷道围岩变形破坏严重,且淋水使锚固剂失效,造成锚杆及锚索锚固力衰减,承载能力下降,严重影响工作面安全生产。针对该问题,采用物理相似模拟实验、数值模拟实验与现场实测相结合的研究方法,分析了淋水软岩巷道围岩在采动影响及不同支护参数条件下的破坏情况,揭示了采动下淋水软岩巷道围岩变形破坏特征并给出了合理的支护参数。实验结果表明:① 采动影响下软岩巷道围岩变形破坏形态具有非对称性,且在淋水条件下,巷道围岩破坏范围进一步增大。② 锚索长度从9 m增加至10 m,巷道围岩破坏范围减小了4.3%;使用12.2 m长锚索支护顶板时,两帮破坏范围大于使用9 m锚索与10 m锚索,主要原因为12.2 m锚索贯通至顶板含水层,导致水体渗流加剧,巷道围岩进一步软化;使用9.2 m长锚索+4.2 m短锚索联合支护时,相较前3种支护参数,巷道围岩破坏范围减小,水体渗流情况明显改善。现场应用结果表明,采用9.2 m长锚索+4.2 m短锚索联合支护时,顶板下沉量、两帮变形量、底板鼓起量比采用原支护参数时分别减小77.5%,65%,76.5%,有效提高了巷道围岩抵抗变形破坏的能力。
The deformation and failure of surrounding rock in soft rock tunnels are significantly exacerbated by the combined effects of mining activities and water immersion erosion. Water immersion leads to the failure of anchoring agents, which reduces the anchorage strength of bolts and cables, thereby diminishing their load-bearing capacity and severely compromising the safety of the tunnel face. To address this issue, a research methodology integrating physical similarity simulation experiments, numerical simulations, and field measurements was employed. The study investigated the failure characteristics of water-immersed soft rock tunnel surrounding rock under mining influence and varying support parameters. The deformation and failure characteristics of surrounding rock under mining and water immersion were identified, and optimal support parameters were proposed. Experimental results indicated that, under mining influence, the deformation and failure of surrounding rock in soft rock tunnels exhibited asymmetry, and under water immersion, the failure range of the surrounding rock expanded further. Increasing the length of the anchor cable from 9 m to 10 m resulted in a 4.3% reduction in the failure range of surrounding rock. When a 12.2 m anchor cable was used to support roof, the failure range on both sides was larger than when using the 9 m or 10 m cables. This was mainly because the 12.2 m cable reached the water-bearing layer in the roof, leading to increased water seepage and further softening of the surrounding rock. The use of a combined support system, consisting of a 9.2 m anchor cable and a 4.2 m short anchor cable, led to a reduction in the surrounding rock's failure range and a significant improvement in water seepage conditions compared to the previous support schemes. Field application results demonstrated that the combined support system, comprising a 9.2 m anchor cable and a 4.2 m short anchor cable, reduced roof subsidence, sidewall deformation, and floor uplift by 77.5%, 65%, and 76.5%, respectively, compared to the original support parameters. This effectively enhanced the surrounding rock's resistance to deformation and failure.
软岩巷道围岩变形破坏特征顶板淋水支护优化联合支护
soft rock tunnel;surrounding rock deformation and failure characteristics;roof water immersion;support optimization;combined support
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会