Ground Temperature Characteristic Analysis On Rubble Slope Embankment And Bridge And Culvert Foundations Of Qinghai-Tibet Railway Permafrost Region

Rubble slope is one of the main kinds of engineering measures protecting permafrost under embankment. In order to cross the river and unstable permafrost region, bridge and culvert frames are Indispensable in the building of Qinghai-Tibet Railway. For holding their effects, several different project frames are constructed in Wudaoliang and mountain feng-huo test segment of Qinghai-Tibet Railway permafrost region, the ground temperature is monitored in one complete freezing-thawing cycle ,natural ground freezing-thawing characteristic and test segment embankments freezing-thawing are analyzed, The following basal cognitions have been drawn:1) The natural ground of Qinghai-Tibet Railway lies in low temperature steady permafrost region, because of none human disturbance, the temperature field is on balanceable state.2) The left side of the embankment of Qinghai-Tibet Railway lies in the sunshine slope, and the right lies in the shade slope. The difference of the thermal effect is obviously on both sides. This leads to the asymmetry of the temperature and the different depth of the temperature field.3) The natural ground temperature is basically the same to the temperature next to the bridge file. This tells us the building of bridge is no impact to protecting permafrost.4) The temperature is clearly different on both sides of the culvert structure. That obviously affected by the sunshine slope and the shade slope of embankment, even in the same side, temperature changes also quite obviously. With the decrease of the distance to the hole, the temperature becomes lower.