Temperature Field Distribution And Subgrade Deformation Of Asphalt And Wide Embankment In Qinghai-Tibet Plateau

G214is an asphalt road with the wide embankment, and it is also the first expressway built on Qinghai-Tibet Plateau. The ground temperature of permafrost is somewhat warmer and this kind of permafrost belongs to high-temperature regions and degradation seriously. Considering the conditions of global warming, based on the temperature field measurement data, the temperature field and deformation of this particular highway is discussed in this thesis. How the temperature field and deformation conditions are affected by the different pavement and different embankment width is analyzed and compared. The conclusions are as follows:1、The average annual temperature in Qingshui River、Maduo、Yushu have increased0.48℃、1.37℃、1.91℃, from1990to2008. And according the altitude increases the rate of warming is slowing.2、Consider the vehicle load on the highway, and build the finite element model found that, temperature spread in the embankment with a lag of about four months compared with surface. Vertical displacement of embankment internal was found the biggest and the displacement variation law was in accordance with the variation of melt soil cores. It shows that the freeze-thaw cycle is the main reason for vertical displacement.3、Temperature of asphalt pavement subgrade is significantly higher than the temperature of the cement pavement subgrade, and the melt soil cores in the cement pavement subgrade disappeared3months earlier than those in asphalt pavement subgrade. The vertical deformation of concrete pavement is2～3mm less than that of asphalt pavement. The melt soil cores in the normal embankment disappeared1month earlier than those in wide embankment. The displacement of normal embankment is always less than that of wide embankment except April and May. The biggest difference between the two vertical displacements occurred in December at about5.53mm.Compare with the cement pavement and the normal embankment, the asphalt road with the wide embankment absorb more beat and produce more displacement, the cement pavement subgrade is better to protect the permafrost than the normal subgrade.