Abstract: The causes for 101 tunnel construction accidents in China between 2009 and 2019 are analyzed to resolve the coupling effect of multiple risk factors on tunnel construction safety. To this end, the risk factors affecting tunnel construction safety are divided into four aspects: human, equipment, environmental, and management factors. Subsequently, the risk coupling theory is introduced into the risk analysis of these tunnel construction accidents, and then the coupling mechanism, classification, and decoupling principle of multiple risk factors accounting for tunnel construction accidents are discussed. Moreover, the NK model is used to build a tunnel constructionrisk coupling model. Based on the NK model, the coupling effect of tunnel construction accidents among multiple risk factors is revealed. The results also show that the more risk factors involved in the coupling effect, the greater the coupling values calculated by the coupling action form, and the greater the tunnel construction risk. It is observed that the coupling effect of humanequipmentenvironment factors causes the greatest tunnel construction risk in the coupling process involving the three risk factors. However, in the coupling process involving only two risk factors, the coupling effect between the equipment and environmental factors poses the greatest risk to tunnel construction. Therefore, based on the decoupling idea, it is established that the coupling effect of various risk factors in tunnel construction can be reduced, including the possibility of further reducing tunnel construction accidents.

Key words: tunnel engineering, construction accident, risk factors, coupling theory, NK model