Abstract: The traditional fixed-value method of designing the soil nail support system for a deep excavation project has challenges such as failure of the excavated area. Therefore, the reliability analysis of various failure modes such as, translational, overturning and pulling failures in the excavation support design of a project were performed by using the checkpoint method and Monte Carlo method. The results indicated that there are some errors in the reliability indices of the supporting structure failure categories predicted by the checkpoint method and the Monte Carlo method. Based on the theoretical and practical project experience, this paper recommends that the checkpoint method should be used. The reliability approach can provide the specific location of the supporting structure that requires improvement.

Key words: deep excavation support, checkpoint method, reliability indices, monte carlo method