昭通隧道岩溶水文地质特征及突涌水危险性评价

Analysis of Karst Hydrogeological Characteristics and Risk Assessment of Water Inrush for the Zhaotong Tunnel

昭通隧道是渝昆高速铁路的控制性工程,也是全线高压富水岩溶隧道的代表性工程,其地形、地质及岩溶水文地质条件较为复杂,有必要查清隧道的岩溶水文地质条件。本文通过对隧址区地形地貌、地层岩性、地质构造、水文地质等条件的研究,分析了岩溶发育程度和岩溶发育规律;根据岩溶水补径排条件,进行了水文地质单位的划分;并在水文地质分区的基础上,进行了隧道涌水量预测和隧道涌突水危险性评价。昭通隧道涌突水危险性总体上为中危险,高危险段主要位于栖霞组(P 1q)、上石炭统(C 3)、岩关阶(C 1y)地层中,占总长度的5.2%,主要与岩性、地形及构造有关。本文岩溶水文地质条件的研究成果对岩溶地区高压富水隧道的勘察设计具有重要参考价值。

The Zhaotong Tunnel is the critical works of Chongqing-Kunming High-Speed Railway and also the representative works of high-pressure water-rich karst tunnels along the entire line.Since its topographic,geological and karst hydrogeological conditions are complicated,it is necessary to make a thorough investigation on the karst hydrogeological conditions of the Tunnel.In this paper,the degree and law of karst development are analyzed through studying the topography,stratum lithology,geological structure,hydrogeology,and other conditions of the tunnel site area;the hydrogeological units are divided according to the conditions of karst water recharge,runoff and discharge;the prediction of water inflow and the risk assessment of water inrush are also made for the Tunnel according to the hydrogeological zoning.The water inrush risk of the Zhaotong Tunnel is generally classified as medium risk.The high-risk sections are mainly located in the strata of Qixia Formation(P 1q),Upper Carboniferous Series(C 3)and Yanguanian Stage(C 1y),accounting for 5.2%of the total length and depending mainly on the lithology,topography and structure.The research findings of the karst hydrogeological conditions in this paper have important reference value for the survey and design of high-pressure and water-rich tunnels in karst areas.