Collapse is one of the typical common geological hazards during the construction of shallow tunnels. Real-time control conducted using dynamic evaluation model and risk aversion is an effective way to ensure the safety of tunnel construction and can be fallen into the following procedures: ①Based on the geological conditions in and out of the tunnel

the risk factors of collapse are analyzed and a fuzzy analytic hierarchy process (FAHP) model of risk assessment for tunnel collapse is proposed. Static evaluation of collapse is then conducted using the risk environment and the proposed model. ②The risk environment is updated based on the actual geological conditions. Furthermore

dynamic evaluation is carried out according to the risk environment

meteoric water

excavation method

support measures and monitoring measurement. ③A risk aversion method is proposed using the results of dynamic evaluation. The purpose of risk reduction can be realized through the optimization of construction scheme. The presented approach has been successfully applied to the construction of Duanjiawu tunnel to avoid collapse

which can provide references to the risk assessment of other similar engineering cases.