Basal heave stability analysis for excavations in deep soft clays

Basal heave stability is one of important pit design checks in the deep soft clays. Typical methods for heave stability in different specifications or codes are first introduced. Then the effects of some factors on the basal heave stability such as insertion ratio and strength of the soil above the retaining wall are presented, and reasonable corrections are proposed for these various factors. The calculation process is simple and convenient for application to design of excavations. Finally, 16 case histories of deep excavations in soft clays in Zhejiang Province are summarized and evaluated. The results by the improved method show that the safety factor of heave stability increases and the applicability of the proposed method is reasonable.