温度应力对机场道面板疲劳损伤的影响

Influence of temperature stress on fatigue damage of airfield pavement slab

目前,中国机场水泥混凝土道面设计中并未单独计算温度应力。参考传热学研究成果在道路工程和场道工程中的应用,采用华北地区某机场实例及其气象数据,建立有限元模型模拟道面结构温度场,并计算分析该机场道面板温度场和温度应力情况。结果表明,温度荷载造成的板底应力曲线与气温、辐射曲线之间存在较大的相位差,板底最大拉应力出现在19—20时。将随时间变化的温度应力与随横向位置变化的飞机轮载应力叠加,并将轮载作用次数按横向、月度、时刻分布,计算机场道面板的累计损伤和剩余寿命。结果表明,采用该方法预测的机场跑道剩余寿命与钻芯取样检测、FAARFIELD软件预测结果,以及跑道实际继续运营时长较为接近。可通过所提方法计算厚度较大的机场道面板的温度应力,对既有机场水泥混凝土道面结构的剩余寿命进行预测评估,并为大尺寸机场水泥混凝土道面板的研究和设计提供参考。

At present,temperature stress is not calculated in the design of airfield cement concrete pavement in China.The finite element model is established to simulate the temperature field of the structure and analyze the temperature stress of the slab using the case of an airport in North China,its meteorological data,and the application of heat transfer theories in road engineering and airfield engineering.The results show that there is a large lag between the atmospheric temperature curve,the radiation curve,and the temperature stress curve of the slab bottom,which leads to the maximum temperature stress occurring at 19 to 20.We may examine the cumulative damage and remaining life of the airport pavement by superimposing the temperature stress,which varies with time,and the gear stress,which varies with transverse position,and dividing the number of gear load actions according to transverse position,month,and hour.The results show that the residual life of the airfield pavement analyzed by this method is close to the prediction result of core sampling and FAARFIELD,as well as the actual continuous operation time of the pavement.This method above can be used to calculate the temperature stress of the slab with large thickness,predict and evaluate the residual life of the existing airfield pavement structure,and is a reference for the research and design of the large-size airfield pavement structure.