对青藏铁路部分路段通风路基温度场的数值分析

NUMERICAL ANALYSIS OF TEMPERATURE FIELD IN SECTIONS OF VENTILATION SUBGRADE ON QINGHAI-TIBET RALWAY LINE

青藏铁路穿越部分冻土路段 ,为保护冻土的热稳定性 ,部分路段采用了通风路基。本文焓法处理带相变的瞬态温度场问题 ,推导了其有限元格式。对青藏铁路中年平均气温在 - 4 .3℃ ,地表年平均温度 - 1℃的路段应用通风路基 ,未来 5 0年 ,在气温上升 2 .6℃的条件下 ,对通风路基的三维温度场进行了数值计算。并和普通的填土路基温度场进行了对比分析。认为在青藏铁路部分路段应用通风路基以增强其热稳定性是有效的。

Some segments of Qinghai-Tibet railway are used the ventilated embankment to ensure the thermal stability for it pass through cold region. The finite element formulate was derived from the differential equation of three-dimension temperature fields taking into phase change by enthalpy-based methods and calculate the temperature distribution of the ventilated embankment under the case that the annual mean air temperature in Qinghai-Tibetan Plateau will be warm up by 2.6 ℃ in the future 50 years and the air yearly-avergae temperature is about -4.3 ℃ or the yearly-average temperature at the native surface is about -1 ℃ . And compare the traditional embankment to the ventilated embankment under the same situation mention above, the ventilated embankment structure can ensure the thermal stability of embankment.