Abstract: A large number of braced excavations in soft soil have shown that the safety factor of basal heave stability through the circular arc sliding method suggested by the current codes is too large when the insertion ratio of retaining structures is small or large. Based on the finite element limit analysis, the problems existing 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. Calculation formulas for the upper and lower limits of the insertion ratio of the retaining structures is proposed. An improved circular arc sliding method for basal heave stability is proposed on the basis of modified circular arc sliding radius and the anti-sliding moment of the retaining structures. The rationality of the improved method is verified through a comparative analysis of engineering cases. The improved method has addressed the problems existing in the current codes, and may provide a beneficial reference for the design of retaining structures in deep braced excavations and the revision of current codes.