大瑞铁路高黎贡山越岭段主要工程地质问题与地质选线

在野外地质调查、钻探、地应力测量和室内测试分析的基础上,对大瑞铁路高黎贡山越岭段规划设计中可能遇到的高地温、高地应力、活动断裂断错、岩爆、涌水突泥、软岩大变形和边坡稳定性等主要工程地质问题进行了论述,认为高地温和热害是制约高黎贡山深埋隧道段建设的关键因素。根据地热钻探、测试资料分析,该区的地热分布受断裂构造控制明显,黄草坝断裂具有阻水隔热的工程地质特性。对比分析认为,C12K方案(34.5 km越岭长隧道方案)位于黄草坝阻水隔热断层之南,通道内相对低温,且在隧道口处避让了古滑坡等不利工程地质问题,在众多比选方案中工程地质条件较好。调查研究结果对大瑞铁路全线贯通具有重要意义。

RESEARCH ON THE ENGINEERING GEOLOGY CONDITION AND RAILWAY ROUTES COMPARISON ALONG THE Mt. GAOLIGONG SECTION, DALI-RUILI RAILWAY

Based on the field geological investigation, drilling, in-situ stress measurement and lab test analysis, this paper illustrates the main engineering geological problems that could be encountered in the Mt. Gaoligong section railway planning and construction, such as high geo-temperature, high geo-stress, active fracture dislocation, rock burst, water pouring out and mud squirting, large deformation of the soft rock, landslide, and so on. The paper deems that the high geo-temperature and thermal harm are the key factors restricting the Mt. Gaoligong deep-buried tunnel section. According to geothermal drilling and lad test results analysis, the geothermal distribution is obviously controlled by the geology structure, and the Huangcaoba fault has the engineering geology of block water and heat insulation. Based on comprehensive comparative analysis, the C12K scheme (34.6 km long tunnel scheme) is a better scheme, located in the relatively low geothermal channel, south of the Huangcaoba fault, and this scheme has avoided some unfavorable engineering geological problems such as the ancient landslide at the tunnel entrance. The survey and research results have great importance for the landslide optimization and further design.