关键词: 砂化白云岩隧洞；地质灾害风险；分级标准；孕灾地质条件；施工处理措施；滇中引水工程

Abstract: During the construction of sandy dolomite tunnels, geological disasters occur frequently. Especially, the construction safety risk of water-rich sandy dolomite tunnels is high, which seriously affects the construction period and investment. In order to study the internal relationship between the geological disaster risk of sandy dolomite tunnels and the geological environment, taking the Yuxi section of the Central Yunnan Water Diversion Project as an example, this paper conducts an in-depth study on the geological disaster cases of sandy dolomite tunnels by using the statistical analysis method. The results show that the geological disaster types of sandy dolomite tunnels include collapse, water inrush and sand gushing, and water inrush; the main influencing factors of geological disasters are faults or compression zones, external water pressure, and the surface water collection area per unit tunnel length. According to the geological conditions of disaster formation, the geological disaster risk level of sandy dolomite tunnels can be divided into four levels: extremely high, high, medium, and general. The research results can provide technical support for selecting construction treatment measures and arranging tunnel alignment schemes for sandy dolomite tunnels, and provide a reference for the survey, design, construction, and management of sandy dolomite tunnels.

Key words: sandy dolomite tunnel; geological disaster risk; classification standard; geological conditions for disaster formation; construction treatment measures; Central Yunnan Water Diversion Project