Analysis Of Horizontal Frost Heaving Force Of Abutment In Permafrost Region

There are some diseases occured on part of the bridge structure in the process of construction and operation of the railway in permafrost regions,For example,the abutment soil frost heave force produced inclined deformation,finally makes the beam segment and abutments are crowded together.Study on bridge pier,permafrost table deformation,China is mainly concentrated in the permafrost engineering disease investigation and management,and the key lies in the sinking of bridge pier and abutment foundation and abutment horizontal frost heaving deformation,stress and deformation problems of little research.Obvious deformation has occurred on the abutment of a bridge in the survey of a railway by China Railway Northwest Research Institute at the end of 2013,this abutment close to the Xining.After excavation,the abutment pile foundation has been cut off.This shows that the horizontal frost heaving force of abutment abutment in permafrost region is harmful to abutment and needs to be studied and controlled.Based on the existing literature,this paper summarizes the formation mechanism,influencing factors,bridge and culvert diseases and their causes in the permafrost regionThis paper analyzes the causes and the current situation of the bridge foundation and transition section of a typical disease;Taking the bridge as the object of analysis,using the finite element software ANSYS,establish Co.element model,simulation of temperature field of frozen soil and the abutment around,the temperature field variation near the abutment and soil,and far away from the abutment(without abutment and subgrade soil under the influence)conducted a comparative analysis of the abutment,It is concluded that the abutment has great influence on the geothermal field nearby,Increase the heat transfer rate,it makes the temperature field around the soil redistribution,and accelerate the freeze-thaw cycle.The thermo mechanical coupling analysis of the temperature field and the structure model is carried out.Study on the size and development of the horizontal frost heaving force behind abutment,and the deformation and displacement of the bridge abutment under frost heaving force.Through the numerical simulation of temperature field around the abutment,obtained from the soil near the abutment,the temperature change is faster,from the far side of the bridge abutment,the heat transfer boundary conditions has little effect.Compared with the unidirectional freezing process and natural foundation from top to bottom,after the construction of the bridge abutment,the heat change of soil near the abutment,the original thermal balance is broken,change of thermal equilibrium conditions the soil temperature distribution changes,these changes have adverse effects on abutment stability,The model is proved to be reliable.The abutment moves forward under the horizontal frost heaving force behind the abutment,Under the combined action of the frost heave force at the bottom and the horizontal force behind the abutment,it is inclined forward.The displacement values are different for each month,The displacement values are different for each month.As the cold and warm seasons alternate,the gap between the abutment and the beam body becomes smaller and finally squeezed together,which is consistent with the observed phenomenon.