基于累积损伤因子的水泥混凝土路面设计(英文)

考虑荷载疲劳应力和温度疲劳应力的综合疲劳方程,计算了单轴单轮及单轴双轮轴载的覆盖通行率,利用累积损伤因子替代标准轴载在交通量换算中的作用,提出了直接计算各级轴载对路面结构总的累积疲劳损伤方法和新的水泥混凝土路面设计方法,并采用两组交通量对轴载累积损伤量的计算方法的准确性与可行性进行了验证。分析结果表明:公路横断面上各点处轴载的作用次数是不同的,各级轴载的累积疲劳损伤峰值不一定在同一位置,利用基于累积损伤因子的水泥混凝土路面设计方法计算得到两组交通量下路面的最不利位置厚度均为22cm,符合设计要求,其他位置厚度可按累积损伤曲线相应减小,此设计方法避免了现行规范基于标准轴载和疲劳耗损等效原则的水泥混凝土路面设计方法与路面实际损伤中存在的差异及轴载换算方法的局限性。

Cement concrete pavement design based on cumulative damage factor

Based on the compositive fatigue equation of load fatigue stress and temperature fatigue stress,the coverage-to-pass ratios of single-axle-single-wheel load and single-axle-double-wheel load were calculated by adopting cumulative damage factor.A direct calculating method of total cumulative fatigue damage of pavement structure produced by multi-axle load and a new design method of cement concrete pavement were put forward by replacing design axle load with cumulative damage factor.The accuracy and application feasibility of calculating fatigue damage produced by multi-axle load were done through a design example with two types of traffic volumes.Analysis result indicates that the acting times of multi-axle load at all points on the cross section of highway are different,and the peak value of cumulative damage of each axle load may be not at the same location.The thicknesses of worst pavement places under the traffic volumes calculated by the design method based on cumulative damage factor are all 22 cm,which meets the design requirement,and the thicknesses of other places can reduce according to the cumulative damage curve.Thereby,it can avoid the differences and localizations of present specification design method of concrete pavement based on standard axle load and equivalent fatigue consumption principle.1 tab,8 figs,12 refs.