基于KENTRACK的铁路沥青混凝土底砟层疲劳特性评价

Evaluation on Fatigue Characteristics of Railway Asphalt Concrete Subballast Layer Based on KENTRACK Software

重复动载疲劳损伤是沥青混凝土底砟层的破坏形式之一。本文建立了沥青混凝土底砟层的三维有限元分析模型,分析其在列车荷载作用下的受力变形特性。采用KENTRACK设计方法分析了沥青混凝土底砟层的疲劳寿命。结果表明:沥青混凝土底砟层等厚度替代基床表层的路基结构形式在列车荷载作用下基床表层的竖向动变形和振动加速度明显减小;沥青混凝土底砟层的层底拉应变在10×10^-6~90×10^-6,处于较低水平;沥青混凝土底砟层具有良好的疲劳耐久性,可用于工程实践。

Repeated dynamic fatigue damage is one of the failure modes of asphalt concrete subballast.In this paper,A three-dimensional finite element analysis model of asphalt concrete subballast was established to analyze its stress and deformation characteristics under the action of train load.The fatigue life of asphalt concrete subballast was analyzed by using KENTRACK design method.The results show that under the action of train load,the vertical dynamic deformation and vibration acceleration of the surface layer of the subgrade are obviously reduced by replacing the surface layer of the subgrade with the same thickness of the asphalt concrete subballast.The bottom tensile strain of asphalt concrete subballast is in the range of 10×10^-6-90×10^-6,which is at a low level.The asphalt concrete subballast has good fatigue durability and can be used in engineering practice.