Research on bearing capacity of pile foundation with impact of subpermafrost water

Abstract

Pile foundation has been widely applied in cold regions. In a special geological condition that subpermafrost water is developed, the shortage of bearing capacity is often encountered in these complex geological areas. In this paper, bearing capacity of pile foundation is studied by finite element method. Combined with geological and geothermal data of some bridge pile in permafrost region, temperature field is simulated by the finite element software ANSYS. Subpermafrost water at the depth of 20 m plays fixed boundary in the calculation model. Environmental temperature plays thermal boundary on the natural surface, including normal environmental temperature with rising amplitude 2.6 °C/50 a. According to the nodal temperature of pile-soil interface, the bearing capacity of pile foundation is calculated by interpolation method. The simulation results indicate that the subpermafrost water is especially significant to the geothermal field. Under impact of subpermafrost water and environment, pile-soil interface is warming, and permafrost base is rising. The bearing capacity of pile foundation decreases obviously with pile-soil interface warming.