Major engineering hydrogeological problems along the Ya’an-Linzhi section of the Sichuan-Tibet Railway

The Sichuan-Tibet Railway is located in the continental collision orogenic belt. Under the special geological structure background, the hydrogeological conditions along the railway are extremely complicated, which seriously restricts the planning and construction and safe operation of the Sichuan-Tibet Railway. To reduce the risk of major engineering hydrogeological disaster, and from the perspective of engineering hydrogeology, by combining the research results of basic geology and engineering geology, this paper expounds the major engineering hydrogeological problems along the Ya’an-Lingchi Section and puts forward suggestions for further research. The results show that the Ya’an-Lingchi section of the Sichuan-Tibet Railway may encounter three major engineering hydrogeological problems, namely, high water pressure and water inrush, high-temperature heat-damage of the tunnel, and the impact of tunnel drainage on ecological environment. Several regional fault zones developed along the railway may control the distribution of strata, hydrothermal activities and mineral resources and the circulation and evolution of groundwater, leading to prominent problems such as high-pressure water inrush, high-temperature heat-damage and groundwater drainage with high TDS in deep and long tunnels through the fault zone. The next step of the research on major engineering hydrogeological problems along the Sichuan-Tibet Railway is mainly to carry out high-precision and multi-scale hydrogeological survey, grasp the development rules and disaster-causing mechanisms of the major problems, and build a fine prediction and evaluation system and an active and passive disaster prevention and control system.