滇中引水工程香炉山深埋长隧洞主要工程地质问题

香炉山深埋长隧洞是滇中引水工程总工期控制性工程,隧洞总长62.596 km,最大埋深1 450 m,具有线路长、埋深大、勘察研究范围广、地质构造背景与岩溶水文地质条件复杂、地下水环境影响敏感等工程特点。勘察期通过大范围线路比选和综合勘察测试研究,逐步选定了隧洞线路并基本查明其工程地质与水文地质条件,对隧洞高地震烈度区抗震与穿越活动性断裂抗断问题、涌突水(泥)与地下水环境影响问题、高地应力与硬岩岩爆及软岩大变形问题、高外水压力问题及穿越煤层、膨胀土特殊岩土工程地质问题等进行了深入分析,为隧洞工程设计、施工提供了可靠的技术支撑,为类似深埋长隧洞的相关研究提供参考。

Major Engineering Geological Problems of Xianglushan Deep-buried Long Tunnel in Central Yunnan Water Diversion Project

Xianglushan deep-buried long tunnel is a control project for the total construction period of the water diversion project in central Yunnan Province. With a total length of 62.596 km and maximum buried depth of 1 450 m, the tunnel is featured with large survey scope, complex geotectonic background and complicated karst hydrogeological conditions as well as sensitive groundwater environment. In survey period, the tunnel line was selected and its engineering geological and hydrogeological conditions and major engineering geological problems were basically ascertained. In this paper, we probe into such problems including the seismic resistance in high earthquake-intensity area and shear resistance of structures passing through active fractures, the environmental impacts of water inrush and mud intrusion, the high geostress, hard rock burst, large deformation of soft rock, high external water pressure, and the special geotechnical engineering problems of coal stratum and expansive soils. The research result offers a technical support for the design and construction of tunnel and a reference for researches on similar deep-buried long tunnels.