青藏高原多年冻土区路基表面浅层地温探讨

Discussion on Shallow Ground Temperature of Embankment in Permafrost Regions on Qinghai-Tibet Plateau

冻土路基温度场是决定冻土路基稳定性的关键因素。在多年冻土区修筑道路工程后,由于工程施工的扰动作用,改变了地表与外界的热交换条件,打破了原有的热平衡状态,使冻土路基温度场变化十分复杂。鉴于青藏高原独特的自然地理环境,实测地温及气象资料获取的困难性,通过青藏铁路沿线有限的实测地温资料,建立了砂砾路面下路基水平表面浅层地温与理论太阳直接辐射强度之间简单的近似线性函数关系,并分析讨论了路基边坡表面浅层地温与太阳直接辐射强度之间线性关系较差的原因。

Temperature field is the key factor which, decides whether the frozen soil embankment is stability. After roadbed building of permafrost, the conditions of thermal exchange between the earth surface and exterior environment are changed due to engineering disturbance, which breaks down the original thermal equilibrium and makes temperature field of frozen soil embankment vary in a complicated way. In view of the specific natural environment of Qinghai-Tibet Plateau, it is difficult to get the monitored ground temperature and meteorological data. A simple linear functional relation between the shallow ground temperature and direct solar radiation is set up under gravel surface. Then, the reason of the bad linear relation between the shallow ground temperature and direct solar radiation on the slope is analyzed.