基于内聚力模型的预裂缝技术机理分析  

Mechanism Analysis of Pre-cracking Technique Based on Cohesive Zone Model

作　　者：刘敬辉[1] 

机构地区：[1]三峡大学土木与建筑学院,湖北宜昌443002

出　　处：《公路交通科技》2012年第7期32-37,共6页Journal of Highway and Transportation Research and Development

摘　　要：基于水泥稳定基层产生收缩裂缝难以避免,并容易扩展到沥青面层而形成反射裂缝,故在水泥稳定基层材料摊铺后养护的1～3 d内,采用振动压路机进行碾压,使其产生网状细裂缝,避免产生宽或长的裂缝,形成了理想的裂缝分布模式。采用内聚力模型对裂缝分布模式进行模拟,并对预裂缝技术的机理进行了理论分析。结果表明:与间距大、数量少而宽的裂缝相比,间距小、数量多的细裂缝引起反射裂缝的可能性要小很多,预裂缝技术释放了早期水泥稳定基层内部由于干缩和温缩蓄积的部分能量。根据能量最小原理,系统的能量越小,系统越稳定。基于能量法的内聚力模型能较好的模拟裂缝,解释了预裂缝技术的本质机理,为预裂缝技术的应用提供了良好的理论基础。Shrinkage cracks are intend to occur in cement stabilized base, and are easy to propagate towards the asphalt surface to form reflective crack. In order to reduce reflective cracking, vibratory roller was used to pass to the cement-treated base in a stage of 1 to 3 days after placement to create a fine network of cracks to avoid the wide or long cracks and create the ideal crack evolution model. The cohesive zone model was introduced to numerically simulate the crack evolution model and interpret the mechanism of pre-cracking. The result shows that （ 1 ） In contrast with a few wide cracks of broad spacing, numerous thin cracks of narrow spacing contribute little to the severe reflection cracking. In terms of energy, the pre-cracking technique released accumulated energy of drying shrinkage and temperature shrinkage in early cement stabilized base. （2） By minimum energy principle, the smaller energy, the more stable. The cohesive zone model based on energy method could better simulate cracking, explain the nature and mechanism of pre- cracking technique, and provide a sound theoretical basis for pre-cracking application.

关 键 词：道路工程 预裂缝 内聚力模型 能量最小原理 收缩裂缝 

分 类 号：U416.1[交通运输工程—道路与铁道工程]