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| Analysis of the Influence of Temperature Rise onthe Stability of FrozenSoil Roadbed Using Finite Element Method |
| CHU Xiao - gang1，ZHANG Jun - ping1，WANG Yin - sheng2，LIU Tao2 |
| (1. Nortliwest Research Institute Co. Ltd of C.R.E. C，Lanzhou，Gansu 730000， China;2. China Railway Academy Co. Ltd，Chengdu，Sichuan 610000，China) |
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Abstract Abstract ： Research purposes ： Influenced by global warming and human economic activities，the vegetation is declining and desertification is deteriorating in the Qinghai – Tibet Plateau，and the physical and mechanical properties of permafrost change，so the stability of the roadbed is facing challenges. In view of the influence of temperature rise on the stability of frozen soil roadbed， the research method of numerical simulation is adopted to analyze and predict the stability of the frozen soil roadbed based on the data of temperature measurement and geophysical prospecting data of permafrost roadbed in Qinghai - Tibet railway. Furthermore，the physical process of the ground temperature transferring and the changing law of tiie thawing area are obtained，providing the basis for tiie analysis of tiie long - term stability of the roadbed and the formulation of t!ie maintenance program. Research conclusions ： (1) Witii the pasage of time，construction of roadbed in permafrost regions shows a trend of gradual degradation， and the limit of the degradation speed of riprap embankment is less than that of the common roadbed. (2) Due to the basic body temperature distribution under endothermic effects on different slopes，the partial temperature field is asymmetric. (3) Compared with the common roadbed； layers of riprap roadbed can play a better cooling and heat insulation ：fect on the roadbed body and the soil below. (4) The annual average temperature of 15 meters belowthe center line of the roadbed is lower than that of 15 meters below the natural surface and increases year by year. (5) The artificial upper limit of riprap roadbed，common roadbed and natural surface decreases annually and the declining rates increase in turn. (6)The research results have guiding significance for the planning， design and construction ； operation and maintenance of the Qinghai – Tibetrailway and the permafrost regions.
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Received: 26 February 2016
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2016, Vol. 33 
