Abstract: The analysis of the basal heave stability for the excavation is the core of deep excavation engineering design in the soft clay, which not only relates to the stability of the excavation and the safety of the surrounding environment, but also affects the construction cost of the excavation project. In this paper, the analytical methods, and applicable conditions of the basal heave stability for the excavation are combed. Combined with the engineering examples, based on the circular slip failure mode in the limit equilibrium method, the influence of the embedment ratio of the supporting structure, the position of the lowest support, the reinforcement in the excavation and the size of the excavation on the basal heave stability of the excavation are analyzed. The results show that increasing the embedment ratio of the supporting structure, reducing the distance between the lowest support and the excavation, and increasing the soil reinforcement at the excavation can effectively increase the basal heave stability of the excavation; For the narrow excavation with small width, the space constraint effect should be considered. If the traditional circular slip mode is too conservative, it will cause a large construction cost waste.

Key words: Excavation, Basal Heave Stability, Supporting Structure, Safety Factor