【作者】 王少华；

【导师】 商庆森；

【作者基本信息】 山东大学 ， 道路与铁道工程， 2008， 硕士

【摘要】 随着公路桥梁建设的快速发展,桥梁结构不断创新,大跨径桥梁已很普遍。但是,随着交通量和重型车辆的增加,许多桥梁建成后不久铺装层就出现了严重的破损、开裂、坑槽、拥抱等早期病害,不仅严重影响了交通的顺畅,而且给桥梁本身也带来了很大的危害。由于对车辆荷载作用下沥青混凝土桥面铺装层的力学响应机理特别是动力学响应机理缺乏系统的研究,在进行桥梁结构设计时对桥面铺装层设计一般不作专门的计算分析,这就为铺装层早期病害的发生埋下了隐患。本文利用ANSYS有限元通用软件,从桥梁的结构特性入手,将梁板与铺装层作为一个整体结构进了系统的静力学、动力学分析,全面研究了桥面铺装层在车辆荷载作用下的损坏机理,提出了沥青混凝土桥面铺装层结构设计的控制指标和合理的设计方法,为今后沥青混凝土桥面铺装层的结构设计探讨了一个新的研究方向,具有重要的理论价值。为了有效防治铺装层疲劳开裂、推移拥抱、离散剥落等早期病害,系统研究了车辆荷载作用下铺装层应力、应变随铺装层厚度、荷载和车速(加载频率)的变化规律,明确了车辆荷载作用下铺装层的破坏机理,提出了以铺装层顶面容许纵向拉应变、底面容许纵向剪应力、底面容许竖向拉应力和顶面容许纵向剪应变作为桥面铺装层结构设计的四项控制指标。通过静力学分析与动力学分析的比较,发现铺装层在静载和动载作用下应力应变随厚度、荷载及车速的变化规律相吻合。因此,在充分考虑应力、应变时效性的基础上,提出了将桥面铺装层在移动荷载作用下的动力效应问题等效转换为静力响应问题进行处理的设计原则。确定了动力效应系数指标(DEI),并且依据此指标提出了铺装层结构设计的合理方法。通过分析车辆荷载作用下铺装层应力应变随厚度的变化规律可知,增加铺装层厚度对于降低铺装层应力、应变的作用是有限的,桥面铺装层合理的设计方案取决于梁跨本身的结构。因此,桥面铺装层的结构设计决不应该成为桥梁设计的附属品,而应该成为桥梁设计中必不可少的一部分内容。更多还原

【Abstract】 The innovation on structure of bridges has been happening continuously with the development of bridges construction, and the long-span bridges have been at large. But serious early diseases have been occurred on many new constructed bridges such as dilapidation、crack、groove and process etc, which not only depressed the traffic fluency seriously, but also resulted in great harm on the girder itself. Dew to the lack of systematical study about the response mechanism, especially about the dynamic response mechanism, for the asphalt concrete pavement under the vehicle loads, there is no professional calculation analysis for the design of asphalt pavement during the design of the bridge, which result in incipient fault for the pavement early diseases. In this paper, taking the girder and asphalt pavement as a ensemble, we study systematiccally about the response mechanism for the asphalt concrete pavement under the vehicle loads, and establish the guideposts for the design of asphalt pavement. Finally, we build up the reasonable method for the design of asphalt pavement, as indicated a new direction for the structural design of the asphalt pavement.In order to prevent effectively the early diseases of the pavement, we study systematically the regularity of the stress and strain with the variable pavement thickness、loads and velocity for the pavement under the vehicle loads.And we established four guideposts for the design of asphalt pavement: tolerant longitudinal tensile strain、tolerant longitudinal sheared stress、tolerant vertical tensile stress、tolerant longitudinal sheared strain.Comparing the static analysis with the dynamic analysis, we draw a conclusion that the regularity of the stress and strain with the variable pavement thickness、loads and velocity for the pavement under the static loads is in accord with that under the moving loads. Therefore , considering the perdurability of the stress and strain completely, we define the Dynamic Effective Index and build up the method for the design of asphalt pavement that transforms a dynamic problem to a static problem according to equality of the integral.By studying the regularity of the stress and strain with the variable pavement thickness、loads and velocity for the pavement under the vehicle loads, we can get that it is limited just by increasing the pavement thickness to reduce the stress and strain, and the reasonable designing scheme for bridge pavement is determined by the structure of the girder itselt. Therefore ,the design of the asphalt pavement is not an appendant but a necessary important part in the design of the whole bridge.更多还原