Abstract: This paper presents the comparative results calculated from the bottom heave calculations in the New National Building Design Specifications, Tianjin City Design Specifications and the Shanghai City Design Specifications. Factors that both considered in three different codes are analyzed and the bottom heave prevention measures are also presented. In a deep excavation site, both the width and the depth of the soil that requires to be improved are presented in accordance with the Prandtl formula.

Key words: Bottom Heave Checking, Circular Slip Mode, Prandtl Formula, Skempton Formula