Temperature And Deformation Analysis On Subgrade In Seasonal Frozen Area

Seasonal freezing and thawing disasters seriously affected the using and security operation of road in seasonal frozen soil area.The soil geothermal and deform distribution research is the important foundation to analysis the roadbed stability in seasonal permafrost areas.Based on the heat transfer and elastic-plastic deformation theory,deduced a two-dimensional numerical equation of temperature-stressdeformation for permafrost embankment;and realized the coupling analysis of temperature and deformation field in seasonal frozen embankment;based on the theoretical model,discussed the the shady and sunny slopes the effect caused by the sun radiation affect and the deformation-stress distribution under a comprehensive action with different subgrade during freezing and thawing of seasonal frozen embankment in Zhangye area,furthermore,in an example of permafrost embankment in Zhangye area,proposed the preventive measures to against the frozen heave and laterally inhomogeneous deformation diseases of seasonal frozen embankment.The simulation results shows that:(1)the temperature between the shady and sunny slopes is different markedly and the temperatures in the sunny slope are higher than that in the shady slope.The temperature difference between the shady and sunny slopes leads to the uneven settlements transversely.(2)global warming has an inhibition to the embankment frozen heave deformation and reduces the subgrade lateral deformation difference;(3)according the soil and climate conditions of Zhangye area,it is most appropriate to take 1.5m for the embankment height;(4)with the increases of subgrade frozen heave rates,the embankment vertical displacement and lateral deformation difference increases too,the vertical displacement in left and right side of the embankment exceeding the allowable vertical deformation value,and will endanger the traffic safety at the same time.In order to satisfy the embankment water stability and deformation requirements,a reasonable embankment height and dry-wet type should be satisfied when designing and construction of the embankment,in addition,to laying the permeable barrier layer at the lower position of embankment in wetting part of the road will reduce and control the occurrence of freezing and thawing disaster.