道面结构不均匀冻胀水热耦合模型试验及现场验证

为更加全面客观地认识机场道面结构的温度场、水分场及其耦合作用的基本规律,为季冻区机场道面结构不均匀冻害的防治提供理论依据和措施建议,设计道面结构不均匀冻胀水热耦合模型试验箱,开展外部水分渗入道肩试验和道面结构不均匀冻胀水热耦合模型试验,并利用现场冻胀量监测结果验证了模型的可靠性和适用性.结果表明:模型试验直观地模拟了跑道与道肩冻胀错台现象,阐明了其产生的原因和机理;揭示了机场道面结构温度场、水分场及其耦合作用的基本规律;外部水分入渗对机场道面结构水分场重分布有较大影响;机场道面结构的不均匀冻害是其内部水热耦合作用的产物,降温速率和温度梯度影响冻结时的水分积聚和迁移,反过来水分的重分布也影响温度的传递.采用室内缩尺物理模型试验和现场监测相结合的研究思路和实施方法不仅为季冻区建筑物不均匀冻胀问题的防治提供了理论基础,也丰富了人们探索水热耦合规律的方法,具有一定的参考价值.

Hydro-thermal coupling model test and field validation of uneven frost heave of pavement structure

In order to understand the basic law of temperature field, water field, and the coupling effects of airport pavement structure, and to provide theoretical basis and measure suggestions for the prevention and control of uneven frost heave damage of airport pavement structures in seasonal frozen regions, we designed a test box and conducted the test of external water infiltration and a model test of uneven frost heave of an airport pavement structure. The reliability and applicability of the model were verified by the results of on-site frost heave monitoring. Results showed that the model test intuitively simulated the phenomenon of faulting of slab ends between runway and shoulder with the reasons and mechanism clarified. It objectively revealed the law of temperature field, water field, and the coupling effects of airport pavement structure. The external water infiltration exhibited a great impact on water field redistribution. Uneven frost heave of airport pavement structure is the result of the coupling of temperature field and water field inside the airport pavement structure. The cooling rate and temperature gradient impact the moisture migration and accumulation, and in turn, the water field redistribution affects the delivery of temperature. The research method of combining the physical model test and the on-site monitoring test not only provides a theoretical basis for the prevention and control of the uneven frost heave of the buildings in the frozen area, but also enriches ways of exploring the law of hydro-thermal coupling.