Finite element method analysis of bottom upheaval of deep foundation pits in soft-clay ground due to excavation

The construction of deep foundation pits in soft-clay ground relates to dewatering problem. In the traditional design, the elastic resistance method is commonly used to calculate their rebound deformation without considering the effect of dewatering. A three-dimensional finite element model is established to simulate the excavation processes of deep foundation pits with or without considering engineering piles on the basis of seepage consolidation coupling by means of ABAQUS. Through comparison and analysis, the basic upheaval rules of pit bottom are summarized. The influencing factors for the bottom upheaval of deep foundation pits are analyzed. The conclusions are drawn as follows: the soils are compacted during dewatering; the foundation pit exhibits plastic upheaval; the dewatering is in favor of the stability of the foundation pits; the engineering piles in the foundation pit in soft-clay ground play an obvious role in inhibiting its bottom upheaval.