冰劈效应对沥青路面表面裂缝的影响性分析

Impact of Ice-split Effect to Surface Cracking in Asphalt Pavement

为研究冻融交替季节冰劈效应对沥青混凝土路面表面裂缝扩展的作用,基于断裂力学方法,采用ABAQUS有限元分析软件建立了路面结构模型,分别研究了路表裂缝在冰劈效应、温缩效应及二者结合作用下的应力强度因子随缝隙内积水深度、裂缝宽度以及裂缝长度等影响因素的变化规律及其相互之间的Pearson相关系数。研究结果表明:冰劈效应下,裂缝内少量积水便能够导致较大的应力强度因子,并且应力强度因子随着积水深度的增加而增长,但增长幅度逐渐放缓;同时较大的裂缝宽度能够导致裂缝更快的扩展,而裂缝长度对应力强度因子影响十分微弱;在冰劈与温缩的联合作用下,应力强度因子与冰劈效应作用下的应力强度因子的Pearson相关系数达到0.99以上,而由温缩效应所导致的应力强度因子相对于冰劈效应并不明显。因此在工程实践中,必须尽快修复路表裂缝,避免其在冻融交替季节受到冰劈效应的危害,从而保护路面的正常使用状况,延长路面使用寿命。

In order to investigate the impact of ice-split on the propagation of the asphalt pavement surface cracking in the alternate freezing and thawing seasons,the pavement structure model was built by utilizing ABAQUS based on fracture mechanics.The variations of stress intensity factor under ice-split effect,thermal shrinkage effect and combination of both effects on pavement surface cracking were calculated.Besides,the effects of ponding depth in crack gap,crack width and crack length were evaluated.The Pearson correlation coefficients between these stress intensity factors were analyzed as well.The results indicate that（1） only a little of ponding in the crack gap can cause high stress intensify factor level under the ice-split effect,the stress intensify factor increases with the ponding depth increases,but the increasing degree decreases;（2） bigger crack width can result in the crack propagation more rapidly under ice-split effect,while the crack length has little effect on the stress intensity factor;（3） when there are both ice-split effect and thermal shrinkage effect exist,the Pearson related coefficient between the stress intensity factors which caused by the stress intensity factor and ice-split effect reaches over 0.99;（4） the thermal shrinkage effect is not significant than the ice-split effect while inducing stress intensity factors.Therefore,the crack on the surface of pavement should be repaired as soon as possible to avoid being harmful by ice-split effect in the alternate freezing and thawing seasons.By this way,the pavement can be kept in good situation and the service life can be extended.