青藏铁路沿线地表和路基表面热力学模式(Ⅰ):物理过程与实验方案

Thermodynamic Model of the Ground Surface and the Roadbed Surface along the Qinghai-Tibetan Railway(Ⅰ): Physical Process and Experimental Scheme

路基表面的热状况具有时空分布的非均匀性 ,筑建在冻土区的路基 ,其下伏冻土层对上边界非均匀热强迫的响应 ,会引起冻土层的冻胀、融沉非均匀变化 ,进而造成路基的变形失稳 .因此 ,了解路基表面热状况的时空变化规律对监测和防治路基冻融病害、保证路基稳定性具有重要意义 .鉴于此 ,从热力学研究角度出发 ,以气候影响因子 -大气辐射传输 -地气交接面辐射特性 -地气间热量交换为研究主线 ,基于能量守恒原则 ,建立针对青藏铁路沿线地表、路基上表面和路基左右边坡表面的普适性热力学数值模式 ,用于高海拔青藏铁路全线的任意坡度和走向的路基表面热状况的定量化研究与应用 .

The thermal distribution on the roadbed surface is inhomogeneous with spatial and temporal variation. For the roadbed built on tundra, the asymmetry heating of the top boundary layer will make an asymmetry change of the permafrost with freezing to swell up or thaw to sink down, and then, cause the roadbed deformation and lose stability. Thus, understanding the spatial and temporal variation of thermal distribution on the roadbed surface is significant to monitor and prevent the roadbed frost-defrost disease and to keep its stability. Considering this, the thermodynamics research is made as a starting point, the climate impact factors, atmospheric radiation transmission, radiation characteristics of the ground-atmosphere interface and the heat exchanging between the ground and atmosphere are studied as a main thread. Based on the energy conservation principle, a commonly practicable thermodynamics numerical model is established, aiming at the environment ground surface, the top surface and the right and left side slope surfaces of the roadbed along the Qinghai Tibetan Railway. The model is suitable for quantitative research and for application to the heat status of the surface on the roadbed, with various slopes and directions, along the whole line of the Qinghai Tibetan Railway.