基于实测数据的机场水泥道面变温效应分析

Investigation into Effects of Temperature Variations on Airport Cement Pavements Based on Measured Data

摘要:

利用上海浦东国际机场“道面状态监测系统”实测的温度、应变和弯沉，分析了水泥道面温度以及温度作用下道面翘曲变形、弯沉、接缝传荷能力的变化.结果表明，土基和基层温度日变化较小，但季节性变化较大；道面板温度沿板厚分布呈非线性，下午时段更显著；全年正、负温度梯度占比基本相同，零温度梯度集中在7:00～10:00和19:00～22:00，且全年呈周期性；此外，在横缝（假缝）和纵缝（企口缝）板边中部以及板角，温度翘曲变形呈同步周期性变化，板角处最大，纵缝（企口缝）板边中部最小，向上（下）翘曲变形的全年最大值均分布在12月～1月（7月～8月）；板中最大弯沉基本保持不变，而板角和横缝（假缝）板边中部最大弯沉日变化和季节性变化显著；假缝和企口缝的传荷能力随平均温度的增大而增大，具有良好的二次曲线关系.建议在道面设计和评价中考虑温度作用的影响.

Abstract:

Using temperature, strain and deflection measured by “Pavement Condition Monitoring System” of Shanghai Pudong International Airport, this study analyzed temperature variation of cement pavements， curling deformation，deflection and load transfer capacity affected by temperature. The results show that daily variation of temperature in the subgrade and base layer is slightly, but seasonal variation is obvious. The temperature distribution along the depth of the slab is nonlinear, and it is more significant in afternoon; the proportion of positive and negative temperature gradients is basically the same throughout the year, and the zero temperature gradient is cyclical throughout the year, concentrating in the period from 7:00 to 10:00 and 19:00 to 22:00. In addition, under the effects of temperature, for the middle of the dummy joint, the slab corner and the middle of the groove joint, the curling deformation shows a synchronous periodic change within one day, and the curling deformation at the slab corner is the largest while it is the smallest for the longitudinal joint; it also shows that the maximum upward (downward) curling deformation happens between December and January (July and August) throughout the year. The maximum deflection at the slab center remains basically the stable, while the maximum deflection at the slab corner and the middle of the dummy joint exhibit significant daily and seasonal variations; the load transfer capacity of both dummy and groove joints increases with the increasing of the average temperature and they have a good quadratic relationship. It is suggested considering the effects of temperature on design and evaluation of cement pavements.