基于参数变异性的连续配筋混凝土路面横向裂缝分布预估方法

Prediction method of the distribution of transverse cracks on continuously reinforced concrete pavement based on variability of parameters

连续配筋混凝土路面(CRCP)的病害冲断主要发生在横向密集裂缝处,故裂缝的分布预估是准确预估冲断的基础。先进行环境荷载作用下CRCP应力和位移分析,然后考虑混凝土干缩、混凝土强度、混凝土线膨胀系数等参数沿路面纵向的变异性以及材料性能随时间的变化,采用增量分析方法和Monte Carlo方法对CRCP横向开裂进行了预估,最后对预估得到的裂缝间距进行了统计分析,并与CRCP的裂缝分布调查结果进行了对比。研究结果表明:由于采用了增量分析方法,可以考虑早期产生的裂缝对后期裂缝的影响;理论预估和实地调查得到的CRCP裂缝均服从Weibull分布,理论预估方法比较合理;混凝土强度、线膨胀系数、干缩以及基层与面板间摩阻系数的变异性还需实测确定。

The punchouts in continuously reinforced concrete pavement （CRCP） mostly develop on the CRCP panels where transverse cracks are spaced closely, so the accurate prediction of pun- chouts depends on the prediction of the transverse cracks distribution. In this paper, the stress and displacement of CRCP under environmental loads were analyzed. Then the distribution of transverse cracks was predicted by using incremental analysis method and Monte Carlo method, in which the variabilities of the parameters （concrete shrinkage, concrete strength, and concrete expansion coefficient） along the longitudinal direction were considered as well as the variation of material properties in time history. Finally, the statistics analysis was conducted to the predicted cracks and the results of cracks distribution were compared with the results obtained from field survey. Results show that the influence of the cracks occurring early on the development of the subsequent cracks can be considered by using the incremental analysis method. The distributions of the cracks both from theoretical analysis and from field survey obey Weibull＇s distribution, which indicates that the method to predict the distribution of transverse cracks proposed in this paper is reliable. The variabilities of concrete strength, concrete expansion coefficient, concrete shrinkage and bond-slip coefficient between concrete and base need to be tested in field in the fu- ture. 6 tabs, 1 fig, 17 refs.