滇中引水工程地质构造背景与地震地质条件极为复杂。香炉山隧洞全长62.60 km,最大埋深1 450 m,穿越滇西北横断山脉及金沙江与澜沧江两大流域分水岭,跨越多条区域性深大断裂,是滇中引水工程中单洞最长、埋深最大隧洞,也是目前国内在建水利工程中施工难度最大、地质条件最为复杂的大深埋超长隧洞。结合香炉山隧洞复杂地质条件、存在的主要工程地质问题,以及可能产生的地下水环境影响风险,系统地总结了香炉山隧洞勘察研究过程中采用的基于3S技术的地质遥感解译、大地电磁测深、千米级深孔勘探测试、复杂岩溶区大埋深超长隧洞选线、地下水三维渗流场数值模拟等勘察关键技术和研究方法,创新性地研发了千米级深孔地应力测试技术、深部岩体水文地质参数测试技术以及适用于复杂地质条件下大埋深隧洞的超前地质预报关键技术;形成了一套较为系统、全面的大埋深超长隧洞勘察关键技术研究方法,为类似工程勘察研究工作提供了重要参考及借鉴。

The Central Yunnan Water Diversion Project features extremely complex geological structure background and seismic geological conditions. With a total length of 62.60 km and a maximum buried depth of 1 450 m, Xianglushan tunnel crosses the Hengduan Mountains in northwest Yunnan, the watershed of Jinsha River and Lancang River, and several regional deep faults. It is the longest single tunnel with the largest buried depth in the Central Yunnan Water Diversion Project and is also the most difficult to construct large, deep and super long tunnel with the most complex geological condition in water conservancy projects under construction in China. In view of the major engineering geological problems and the potential risks of groundwater environmental impact, we systematically summarize the key survey technologies including 3S-based geological remote sensing interpretation, magnetotelluric sounding, kilometer-level deep hole exploration and testing, route selection of large deep-buried and super long tunnels in complex karst areas, and numerical simulation of three-dimensional seepage field of groundwater. We also developed some key technologies of advanced geological prediction applicable for large, deep-buried, and long tunnels in complex geological conditions, kilometer-level deep hole geostress testing technology, as well as deep rock hydrogeological parameter testing technology. Such technologies form a whole set of systematic and comprehensive research methods for investigating large buried and super long tunnels.