Theoretical Study On Horizontal Frost Heaving Force Of Shallow Buildings In Permafrost Regions

ABSTRACT:The engineering building in permafrost regions usually suffered from the destruction of horizontal frost heaving force produced by freezing soil. The damage caused by freeze injury had a severe influence on the service performance of buildings. In this thesis, the formation mechanism and influence factor of horizontal frost heaving force were analyzed by collecting the existing research results. The development and distribution law of horizontal frost heaving force of shallow buried buildings in permafrost regions were calculated by finite element method. It can be concluded as follows:(1) Temperature, soil property and moisture content have a significant influence on horizontal frost heaving force. The influence of moisture content is the most outstanding. At the same time, moisture content, temperature and soil property have obvious interaction effects.(2) The shallow buried buildings in permafrost regions were in two-way frozen state. Its temperature field is determined by both burial depth and structural style. There are a great number of differences in temperature field when the buildings own different burial depths and structural styles.(3) For the shallow buried buildings with a higher rigidity, horizontal frost heaving force was larger on the top. The horizontal frost heaving force was reduced along the burial depth. The reduction of the force in the region between one-third and a half of burial depth was the most drastic, while it reached the minimum in the middle. For the shallow buried buildings with a lower rigidity, horizontal frost heaving force on the top was the smallest. The horizontal frost heaving force was increased along the burial depth. The increase of the force in the middle was reached the maximum.(4) The distribution of horizontal frost heaving force in different structural buildings is basically consistent. The difference in the middle part of burial depth is relatively higher, while it is smaller on the top and at the bottom. The distribution form of horizontal frost heaving force along the buried depth in the building with the same structural style but different buried depths is basically the same. The value of the force in the middle of the buried depth differs a lot, while the values on the top and at the bottom almost have no difference.(5) The development of horizontal frost heaving force can be divided into four stages, i.e., formation stage-rapid growth stage-slow growth stage-attenuation stage.