青藏高原多年冻土区路基温度场数值模拟

Numerical simulation of thermal field in permafrost embankments of Qindhai-Tibet highway

根据青藏公路沿线近30年的气象资料,考虑太阳辐射、气温、风速、风向、蒸发等第二类、第三类边界条件,结合路线走向、路基高度、路面类型状况,对青藏公路五道梁地区路基温度场进行有限元分析。经验证,计算结果与路基温度场实测资料基本一致。有限元分析表明,在年周期内路基边界处的温度仍然可按正弦曲线较好地加以拟合;路线走向对冻土路基温度场的对称性有着重要影响,东西走向路基阴阳坡效应最为显著,南北走向路基的温度场基本对称;当路基存在坡向差异时,其阴阳坡效应的强弱与季节密切相关,夏季较弱,冬季较强。

The 30 years＇ meteorological datum along the Qinghai-Tibet highway, such as the solar radiation, air temperature, wind velocity, soil moisture evaporation, were concluded as the combination of the second and third boundary condition for thermal field, and the route strike, embankment height, pavement type were also taken into account. The FEM model of embankments was set up. The calculation results have a good agreement with field measurements. The analysis results show that, in a year circulation, the embankment boundary temperatures vary as sinu- soidal wave. Route strike has great influence on the thermal regime symmetry in embankment in permafrost region. The asymmetry of thermal field is the strongest in E-W strike embankment and the mino- rest in N-S strike embankment. The asymmetry of thermal field is closely related with season variation, which is the minorest in summer and the strongest in winter. 4 tabs, 10 figs, 7 refs.