加铺沥青层路面纵缝在不同动荷载作用下的变化研究

Research on Longitudinal Crack Propagation Law of Asphalt Overlay Pavement Under Different Dynamic Loadings

采用有限元法对旧水泥混凝土路面加铺沥青混凝土面层路面结构进行数值建模,并分别计算研究原水泥混凝土面层作为基层时,层底裂缝在振动压路机荷载及标准车辆荷载作用下的裂缝尖端应力强度因子。通过计算对比发现,虽然振动压路机工作时有较大的激振力和振动频率,但其并不会增加路面裂缝扩展的概率;压路机振动荷载加载初期,由于存在较为明显的振动效应,会使路面层底纵向裂缝尖端出现较大的应力强度因子,因此需要避免在纵向裂缝上启动压路机。

The finite element method is used to numerically model the pavement structure of the old cement concrete pavement with asphalt overlay in this paper.The stress intensity factor of the longitudinal crack tip in the original concrete pavement under the action of vibratory roller and standard vehicle load is calculated and compared.It is found that although the vibratory roller has a large excitation force and vibration frequency when it is working,it does not increase the probability of crack propagation in the pavement.In the initial stage of vibration loading,due to the more obvious vibration effect,a larger stress intensity factor will appear at the tip of the longitudinal crack,which means that it is necessary to avoid starting the roller on the pavement with longitudinal crack.