【作者】 郑选荣；

【导师】 戴俊；

【作者基本信息】 西安科技大学 ， 防灾减灾工程与防护工程， 2005， 硕士

【摘要】 目前,在旧路修复中,最常用而且最经济的方法是在己破损的路面上加铺沥青混凝土。这种修复方法最主要的问题是加铺层反射裂缝的形成,即原路面中存在的裂缝在交通荷载、环境因素以及二者的共同作用下扩展并延伸到新的面层中。反射裂缝扩展是沥青混凝土加铺层早期破坏的主要因素之一。因此,在进行沥青加铺层设计时,首先需要研究反射裂缝的扩展规律及其预防对策。本文采用线弹性断裂力学理论对反射裂缝的扩展进行了全面分析,并对玻璃纤维格栅防止反射裂缝的作用进行了研究。具体内容包括: 对反射裂缝尖端应力场的奇异性进行描述,建立平面断裂问题应力强度因子的 有限元解。 对含裂缝路面在交通荷载和温度荷载作用下的结构反应进行深入分析。试图得 出沥青加铺层厚度及模量与地基模量比对应力的影响规律。并利用弹性三层体系,分析沥青层对应力的影响规律。 研究玻璃纤维格栅在防治与控制反射裂缝中的作用机理,对其施工工艺进行详 细的介绍。 分析表明,导致旧路面裂缝向沥青加铺层反射的主要原因是非对称荷载和温度荷载作用下的裂缝尖端应力集中;采用加铺玻璃纤维格栅来抑制反射裂缝的措施是非常有效的。更多还原

【Abstract】 Many existing pavement,both rigid and flexible,have been rehabilitated with bituminous overlays.However,reflection crack occurs in these new overlays due to the movement of existing pavements under environmental or traffic loads,and/or a combination of both. This reflection crack is the main cause of early deterioration of bituminous concrete overlays, and therefore its prevention is an important consideration in the design of overlays.In this paper, linear fracture mechanics is employed to give a full analysis to the mechanism of reflection Crack propagation. After depicting the singularity of stress field at the top of crack,the finite element method to calculate stress intensity factor of plain fracture problems is established. The structural response of pavement suffering reflection crack is deeply analyzed in terms of traffic load and thermal load.The effects of the thickenss of overlay,its modular and base modular on the stress are found.The effects of the existing asphalt layer on the stresss in overlay have been analyzed in elastic three layer system too. This paper also studies the principle respectively how glass fiber grid prevents and controls reflection crack,and introduces corresponsive construction crafts in detail. The conclusion from analysis is that the reflection crack’s propagateion is decided by the shear stress and thermal stresss at the top of the crack;The use of the GLASGRID is very effective to refrain the reflection crack in the new overlay.更多还原