王利明. 大倾角断层不良地质下TBM隧道稳定性分析[J]. 煤炭学报,2024,49(S1):1−8. doi: 10.13225/j.cnki.jccs.2023.0359
引用本文: 王利明. 大倾角断层不良地质下TBM隧道稳定性分析[J]. 煤炭学报,2024,49(S1):1−8. doi: 10.13225/j.cnki.jccs.2023.0359
WANG Liming. Stability analysis of TBM tunnel under unfavorable geological conditions of large dip faults[J]. Journal of China Coal Society,2024,49(S1):1−8. doi: 10.13225/j.cnki.jccs.2023.0359
Citation: WANG Liming. Stability analysis of TBM tunnel under unfavorable geological conditions of large dip faults[J]. Journal of China Coal Society,2024,49(S1):1−8. doi: 10.13225/j.cnki.jccs.2023.0359

大倾角断层不良地质下TBM隧道稳定性分析

Stability analysis of TBM tunnel under unfavorable geological conditions of large dip faults

  • 摘要: 依托滇中引水大理Ⅰ段香炉山隧洞工程,利用自主研制的微型TBM掘进综合试验系统,开展了TBM穿越断层不良地质工况室内模型试验及数值模拟,研究高地应力下断层对TBM隧道稳定性的影响,分析总结隧道围岩应力应变变化规律及隧道破坏现象,揭示断层不良地质卡机致灾机理。研究结果表明:利用微型TBM掘进综合试验平台成功实现了高地应力条件下TBM开挖大倾角断层工况相似模拟试验,隧道成型质量好。TBM掘进过程中隧道上部围岩首先产生裂缝,当TBM掘进至两种材料交接处时拱顶产生少许掉落,在TBM刀盘整体进入断层带后,拱顶产生大范围塌方,最终形成筒仓式塌落腔,隧道结构被破坏;受断层界面上方围岩滑动影响,原岩内(交界面下方)围岩压力整体呈现先增大后减小的趋势。TBM掘进时对掌子面前方围岩压力影响范围主要在0.43D~0.50D(D为洞径),围岩压力最大增大1.19倍。隧道拱顶上方内部围岩位移随TBM掘进具有4个明显的变化阶段。上部围岩越靠近隧道轮廓线变形越大,TBM穿越断层交界面时围岩变形速率最大,对围岩内部位移影响范围主要在掌子面前方1.21D和上方1.50D以内,断层影响范围约在1.73H(H为断层交界面水平投影长度)以内。这主要是由于断层交界面上方松散围岩滑移松动,同时它极易导致TBM卡机,因此施工宜先对断层交界面处进行超前处理,降低TBM施工风险。

     

    Abstract: Based on the Dali I section of the Central Yunnan Diversion Dali Tunnel Project, an indoor model test of TBM traversing faulted geological conditions under high ground stress was carried out using the self-developed miniature TBM tunneling integrated test system to study the impact of faulting on the stability of TBM tunnels under high ground stress, analyze and summarize the change of stress and strain in the surrounding rock of the tunnel and the tunnel damage phenomenon, and reveal the disaster-causing mechanism of faulted geological jamming. The research results show that the TBM tunneling process first produces cracks in the surrounding rock at the upper part of the tunnel, and then a small drop in the vault when the TBM bores into the intersection of the two materials. The pressure on the surrounding rock in front of the palm face is mainly in the range of 0.43D~0.50D (D is the diameter of the hole), with the maximum increase of 1.19 times in the pressure on the surrounding rock. The internal rock displacement above the tunnel vault has four distinct phases of change with TBM tunneling. The closer the upper surrounding rock is to the tunnel contour line, the greater the deformation. When TBM passes through the fault interface, the deformation rate of the surrounding rock is the highest. The impact range on the internal displacement of the surrounding rock is mainly within 1.21D in front of the palm and 1.50D above it. The impact range of the fault is about 1.73H (H is the horizontal projection length of the fault interface), which is mainly caused by the loose sliding of the surrounding rock above the fault interface, and it is also easy to cause TBM jamming, Therefore, it is advisable to carry out advanced treatment at the fault interface during construction to reduce the risk of TBM operation.

     

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