青藏铁路旱桥的三维温度特性分析

根据带相变瞬态温度场问题的热量平衡控制微分方程, 应用有限元法对青藏铁路旱桥的温度特性进行了三维数值分析.结果表明: 修建于高温极不稳定冻土地段的旱桥在将来运行20 a的过程中对冻土有很好的制冷作用, 能很好地保护冻土, 保证铁路的运行安全, 并且分析和说明了在建的青藏铁路在高温极不稳定冻土地段的采用旱桥的形式是可行的和必要的.

Three-dimensional Temperature Character Analysis of the Land Bridge on the Qinghai-Tibet Railway

Attracted worldwide attention, the Qinghai-Tibet railway is built on the frozen soil regions more than 550 km long, of which about 100 km are built on high-temperature unstable frozen soil. The key to the success or failure of the railway is whether the embankment under it is stable or not. To resolve the problems of frost heaving and the thawing settlement, to insure the stable of the embankment and the unimpeded move of wild animals, the Qinghai-Tibet railway forms a land bridge on the high-temperature unstable frozen soil. However, up to now, nobody has researched the temperature character of the land bridge in cold regions. In this paper, based on differential equations of the problem on temperature field with phase change, a three-dimensional temperature character analysis of the land bridge built in cold regions with high-elevation was made by using the finite element formulae. The analysis shows that in the coming 20 years, the land bridge built on the regions of high-temperature unstable frozen soil could provide cool energy for the frozen soil greatly and protects the frozen soil under it obviously, and then meets the requirement of thermal stable of the frozen soil under it. Moreover, the analysis also proves that to build land bridge for Qinghai-Tibet railway in high-temperature unstable frozen soil regions is indispensable and feasible.