ABSTRACT
The buttress and cross wall is an excavation support system that has been widely used for the protection of the adjacent building during excavation. However, their mechanism in resisting the basal heave stability has not yet been fully understood. In this study, a series of three-dimensional finite element analyses were conducted to assess the influence of buttress and cross walls on basal heave stability in deep excavations. The results showed that the frictional resistance acting on the contact surface area between the wall (including buttress and cross wall) and the surrounding soil plays an important role in resisting the basal heave failure. Hence, increasing the dimension of the buttress and cross walls could enlarge the frictional area, which resulted in enhancing the factor of safety. Furthermore, a new simplified method considering the buttress and cross wall properties was proposed, which was validated by the finite element method.
