高黎贡山隧道破碎地层TBM施工技术与应对方法研究

Construction Technology and Countermeasures for TBM Boring in Broken Ground of Gaoligongshan Tunnel

为解决大瑞铁路高黎贡山隧道出口段岩石破碎地质影响TBM施工的问题,针对掌子面前方破碎围岩,提出掌子面前方化学灌浆加固、小导洞开挖及超前管棚等方法联合帮助TBM脱困,同时提出护盾向前延伸、刮渣口限粒板加密的TBM设备改进应对方法;针对破碎围岩露出护盾后易塌落问题,提出隧道顶部加强初期支护和化学灌浆、隧道腰部立模灌浆、隧道底部机械化清渣的应对方法。现场实践表明:采用上述方法,有效降低了TBM在破碎地层掘进刀盘被卡的风险,即使刀盘被卡也能在可控的时间内及时脱困;同时还有效提高了TBM通过破碎地层的施工速度。

The broken ground at exit section of Gaoligongshan Tunnel on Dali-Ruili Railway has adverse effect on TBM construction. Hence, a series of mehods for TBM releasing in broken ground, i. e. chemical grouting reinforcement ahead of tunnel face, small guide hole excavation and advance pipe-roof, are proposed;and TBM equipment improvements such as extending the shield and increasing the limit plate on scraper mouth are proposed as well. And then, for the problem that the surrounding rock is prone to collapse after shield passing, some countermeasures including strengthening the primary support and chemical grouting of tunnel top, installing template and pouring cement slurry at the waist of tunnel, and mechanized slag clearing at the bottom of tunnel, are put forward. The field practice shows that by adopting the above-mentioned methods, the risk of TBM being jammed in the broken ground is reduced effectively, and the cutterhead releasing time is reduced, which improves the TBM boring efficiency in broken ground.