岩溶台地高压富水特长隧道勘察的精细化探索

岩溶台地高压富水特长隧道精细化勘察应在收集和分析区域地质资料、前期勘察成果、前人研究成果及类似工程案例的基础上,找出主要的水文与工程地质问题,针对这些问题进行水文地质与工程地质调绘和地球物理探测,在此基础上构建地质模型,并采用有针对性的水文地质钻探、工程地质钻探、现场监测与测试及数值仿真等方法与手段,对地质模型进行验证、丰富与优化。本文以G59呼北高速张家界至官庄段沅古坪隧道为研究对象,为了查明岩溶台地高压富水特长隧道的水文地质与工程地质条件,在水文地质与工程地质测绘、地球物理探测、地质钻探及工程评价等方面进行了精细化勘察的探索与研究,提出了精细化勘察技术思路。根据精细化勘察技术思路,细分隧道区域的地下水系统,划为17个地下水系统,隧道穿越9个地下水系统,采用空气潜孔锤-孔内电视复合方法查清了大湖村段水文地质结构,在此基础上,采用解析法和数值法预测了隧道涌水量,隧道涌水量在150mm降雨量条件下为26.93×10⁴ m³/d,评价了突水突泥风险,在大湖村岩溶泉系统及柏杨坪岩溶地下河系统为高风险区。

Fine Survey of High Pressure and Rich Water Super Long Tunnel in Karst Platform

Based on the collection and analysis of regional geological data, preliminary investigation results, previous research results and similar engineering cases, the main hydrogeological and engineering geological problems should be found out in the fine survey of karst platform high-pressure water rich super long tunnel. Hydrogeological and engineering geological mapping and geophysical exploration should be carried out to solve these problems, and the geological model should be constructed on this basis. The methods of hydrogeological drilling, engineering geological drilling, field monitoring and testing and numerical simulation are used to verify, enrich and optimize the geological model. Taking Yuanguping tunnel of Zhangjiajie to Guanzhuang section of G59 Hubei expressway as the research object, in order to find out the hydrogeological and engineering geological conditions of high-pressure water rich super long tunnel in karst platform, this paper explores and studies the fine survey in the aspects of hydrogeological and engineering geological mapping, geophysical exploration, geological drilling and engineering evaluation, and puts forward the technical ideas of fine survey. According to the idea of fine survey technology, the groundwater system in the tunnel area is subdivided into 17 groundwater systems, and the tunnel passes through 9 groundwater systems. The hydrogeological structure of Dahu Village section is investigated by using the air DTH hammer borehole and TV composite method. On this basis, the tunnel water inflow is predicted by using analytical method and numerical method. The tunnel water inflow is 26.93×10⁴ m³/d. The risk of water and mud inrush is evaluated. The karst spring system in Dahu village and the karst underground river system in Baiyangping are high risk areas.