Abstract:In order to accurately investigate the development of hidden karst in highway tunnels in Karst areas, provide reliable basis for later treatment design, effectively reduce water inrush and mud inrush accidents during excavation, scientific exploration model can effectively overcome the difficulties of concealment and complexity of karst development, and achieve the purpose of fine investigation of tunnel karst development. This paper studies a comprehensive exploration model combining geological survey, geophysical exploration, drilling, three-dimensional scanning in boreholes and hydrogeological experiments, and has been successfully applied in the karst exploration of Deze Tunnel of Zhanhui High-speed in Yunnan Province. The results show that the geological survey work was in the first place, and the karst development in the work area can be judged macroscopically; the tunnel through geophysical exploration can be used to determine the specific karst development form and the karst development. Scope delineation can guide the selection of drilling location; drilling work can verify geophysical anomalies and accurately judge the location and scale of karst development; three-dimensional scanning in boreholes can accurately visualize the karst development form; hydrogeological experiments can judge the nature of site rock mass; through various means and progressive ways, it can effectively and accurately determine the karst development. The development of karst in tunnels is investigated. It can be seen that the new tunnel karst fine survey model is effective in practical application and has good application value in similar work areas.