大瑞铁路高黎贡山隧道花岗岩蚀变带存在地应力大、含水丰富、水压力高、节理裂隙发育、围岩软弱破碎、地层软硬不均、遇水软化崩解、砂化泥化严重等问题，容易发生大变形、坍塌和涌水突泥，导致TBM卡机。为解决上述问题，在正洞和平导外侧各增加一个迂回导坑，采用钻爆法进行侧方绕行施工。通过超前正洞和平导，进一步探明地质，同时提前释放高地应力和适量排水降压，并提前对正洞和平导花岗岩蚀变带进行处理，为正洞和平导TBM脱困创造条件。通过分析隧道出口平导右侧迂回导坑花岗岩蚀变带施工风险，总结平导右侧迂回导坑第一循环注浆的经验，并通过理论计算和现场施工数据分析确定主要注浆参数。研究表明： 在蚀变花岗岩地层采用大扭矩、大推力凿岩机冲击回转钻进和高气压风动潜孔锤冲击钻进2种高效的钻孔方法，短循环多分段前进式高压力注浆工艺，多种注浆材料组合注浆方式，可在一定程度上解决花岗岩蚀变带注浆堵水加固难题。
The granite alteration zone of the Gaoligongshan tunnel on the Dali-Ruili railway presents challenges such as high ground stress, abundant water content, high water pressure, well-developed joint and fissure systems, weak and fragmented surrounding rock, uneven hardness of the strata, softening and disintegration upon encountering water, and severe sandification and mudification. In addition, the zone is prone to large deformations, collapses, and water and mud outbursts, leading to TBM jamming. To address these issues, an additional detour guide tunnel is constructed on both outer sides of the main tunnel and the horizontal guide tunnel. Construction is carried out using the drilling-and-blasting method for lateral passages. First, advance geological prediction is conducted for the main and parallel guide tunnels; second, the high ground stress is released in advance and limited drainage is implemented to reduce the water pressure; and third, the granite alteration zones of the main tunnel and the parallel guide tunnel are pregrouted, creating conditions for the jam-release of TBM. Based on the construction risks associated with the granite alteration zone, the results of the first cycle of grouting on the right side of the detour guide tunnel are summarized, and the main grouting parameters are determined through theoretical calculations and on-site construction data analysis. Finally, various techniques, including two efficient drilling methods (large-torque and large-thrust impact rotary drilling, and high-pressure pneumatic drill for deep-hole construction), short-cycle multisegment high-pressure grouting technology, and combined grouting methods using multiple grouting materials, are developed and applied, successfully grouting and blocking the water in the granite alteration zone.
