【作者】 吴迪；

【导师】 刘来君；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2016， 硕士

【摘要】 地震破坏是斜拉桥破坏的主要形式之一。强震将造成斜拉索断裂、主梁开裂、主塔破损、支座破坏等,给人民生命和财产安全带来巨大损失。在大跨度斜拉桥的设计中,主梁形式的选择相对较少,基本局限于混合梁、钢箱梁两种形式。相比于大跨度斜拉桥设计,跨径在400米及以下的中等跨度斜拉桥设计中,主梁形式的选择更多且灵活,主要包括:混凝土梁、组合梁、混合梁、钢箱梁等形式。因此,在中等跨度斜拉桥初步设计阶段,主梁形式的选择往往困扰着许多设计工作者;原因在于主梁形式的确定是一项非常复杂的任务,由多种因素综合决定。更重要的是主梁形式往往决定着斜拉桥的桥跨布置、索塔形式及高度、基础类型及整体造价等。然而,在以抗震设计为控制因素的地域进行斜拉桥建设,地震则是斜拉桥主梁形式选取的决定性因素。因此,基于抗震性能的中等跨度斜拉桥主梁方案比选就显得尤为的重要。本文以榕江特大桥实际工程为依托,在建立有限元计算分析模型,详细对比分析三种主梁形式斜拉桥方案动力特性的基础上,对比分析了加速度E1反应谱及地震波加速度时程分析两种地震动荷载作用下的斜拉桥主要构造地震响应。包含了斜拉索内力、主梁内力及索塔内力变化对比分析、主塔位移及主梁位移变化对比分析、斜拉桥地震易损部位内力及应力变化对比分析。详细阐述了每种主梁方案在不同地震荷载作用下的优势及劣势。得出了组合梁斜拉桥方案整体抗震性能最优,混合梁斜拉桥方案整体抗震性能较差这一对比分析结果。本文结论对斜拉桥工程设计,特别是初步设计具有一定的指导作用。更多还原

【Abstract】 Earthquake damage is the main form of damages to the cable-stayed bridge. Strong earthquake will cause fracture of the cable, girder crack, main tower broken, bearing damage, etc. It will cause heavy loss for the security of people’s life and property. In the design of large span cable-stayed bridge, the choice of the main girder form is relatively small, confined to mixed beam and steel box girder. Compared to the large span cable-stayed bridge design, the design of span under 400 meters middle span cable-stayed bridge, the choice of the girder form is flexible, mainly includes: concrete beam, mixed beam, composite beam, steel box girder and other forms. Hence, In cable-stayed bridge preliminary design stage, many design professionals are often plagued by the choice of the form of main girder; the reason is that the determination of main girder forms is a very complex task, comprehensive decision by a variety of factors. More importantly, girder forms often decide the arrangement of bridge spans of cable-stayed bridge, the cable tower form and height, the base type, and overall cost etc. However, In the region which seismic design for cable-stayed bridge construction are the control factors, the ground motion is the decisive factors in cable-stayed bridge girder form selection. As a result, the comparison of cable-stayed bridge girder scheme based on the seismic performance is particularly important.Based on the rongjiang super-large bridge engineering as analysis object, based on the seismic performance in preliminary design stage of this bridge main girder form scheme comparison. By establishing the finite element analysis model, on the basis of detailedly analyzing the dynamic characteristics of three kinds of forms of main girder cable-stayed bridge, contrast analysis the earthquake response of the cable-stayed bridge main structure under the two seismic loads of the acceleration E1 response spectrum and seismic acceleration time history analysis. Containing the contrast analysis of the main girder and the cable tower and the cable internal force change, the contrast analysis of the main tower and main girder displacement change, the contrast analysis of internal force and stress on cable-stayed bridge seismic damageable parts. This article elaborate the advantages and disadvantages of each main girder scheme under the different seismic load. It is concluded that the overall seismic performance of composite beam cable-stayed bridge is the optimal, and the overall seismic performance of hybrid girder cable-stayed bridge is the worst. For the cable-stayed bridge engineering design, especially in the preliminary design, this article conclusion has a certain guiding role.更多还原