Abstract: A large number of braced excavations in soft soils have shown that the safety factor of basal heave stability by using the circular arc sliding method suggested by the current codes in China is too large when the insertion ratio is small or large. Based on the finite element limit analysis, the existing problems in the current codes are deeply investigated. The variation mechanism of the safety factor of basal heave stability, the circular arc sliding radius and the anti-sliding moment of the retaining structures is clarified with the increase of the insertion ratio of the retaining structures. The formulas for calculating the upper and lower limits of the insertion ratio of the retaining structures are further established, and an improved circular arc sliding method for basal heave stability is proposed. The rationality of the improved method is verified through a comparative analysis of engineering cases. The improved method has addressed the existing problems in the current codes. It may provide a beneficial reference for the design of retaining structures in deep-braced excavations and the revision of the current codes.