Numerical analyses on mechanical performance of flat buried approach slab and soil deformation

The vulnerability problem of expansion joints could be fundamentally resolved using the concept of jointless bridges. The longitudinal deformation of the superstructure can be transferred to the backfill by using the approach slab. The flat buried approach slab (FBAS) has been used in many jointless bridges in European countries. In order to understand the mechanical performance of FBAS and soil deformation, a finite element model (FEM) was implemented in PLAXIS. Considering the friction between the FBAS and soil, the buried depth, the FBAS length and thickness as parameters, a parametric analysis was carried out. According to the obtained results and in order to reduce the soil deformation above the FBAS, it is suggested to increase the friction between the FBAS and sandy soil, and the buried depth of FBAS. Moreover, it should be paid attention to the vertical soil deformation and the concrete tensile stress of FBAS in pulling condition.