洋浦大桥受力特性分析

【作者】 钟海；

【导师】 张晔芝；

【作者基本信息】 中南大学 ， 土木工程， 2011， 硕士

【摘要】 海南洋浦大桥主桥为(58.5+63+58.5+460+58.5+63+58.5)m七跨双塔双索面的混合式结合梁斜拉桥,通行双向六车道。该桥边跨采用预应力边主梁结构而中跨采用工字钢结合梁结构,边跨和中跨通过钢-混凝土结合段过渡,受力复杂。此种主梁截面形式的混合梁斜拉桥在国内外公路桥梁中的应用较少,本文对该桥及其钢-混凝土结合段受力性能进行了研究,主要完成了以下工作：1、本文采用空间板梁法建立了洋浦大桥的全桥空间有限元模型,对其在恒载、最不利活载、温度荷载、风荷载及荷载组合作用下的受力性能进行分析。计算结果表明：该桥各构件受力合理,强度和刚度均满足要求。2、对主梁、桥面系在考虑和不考虑混凝土徐变效应两种情况下的受力性能进行了对比分析。结果表明：考虑徐变效应后,桥面板的相对刚度降低,内力重分配时,钢主梁承受更大比例内力,其内力增大,而桥面板内力减少。3、建立了钢-混凝土结合段精细的空间有限元模型,对其受力性能作了分析研究,结果表明：各种工况作用下,全部钢构件和混凝土顺桥向均受压；钢构件和混凝土应力均小于设计值,且有较大的余量；钢与混凝土的应力在钢-混结合段都较小；钢-混结合段与右边的纯钢段传力较顺畅,在结合段与纯钢段的连接处以及结合段与纯混凝土段的连接处应力集中现象不严重。4、研究了钢-混凝土结合段在超载工况下(恒载+1.6倍轴压最大活载)受力性能,结果表明：钢梁在钢-混结合段及结合面以右1.6m范围内大部分区域的应力均小于-170Mpa；混凝土在钢-混结合段及结合段以左3m范围内大部分区域的应力均小于设计值-22Mpa,表明钢-混凝土结合段有足够的承载力。本文的研究成果为海南洋浦大桥设计提供了依据,对其他混合梁斜拉桥也有参考价值。更多还原

【Abstract】 The main bridge of Hainan Yangpu Bridge is designed as a hybrid girder cable-stayed bridge with span arrangement (58.5+63+58.5+460+58.5+63+58.5) m, double pylons and two cable planes,which allows two-way six lanes. The side spans are prestressed girders while midspan’s joist steel composite-beam structure, which are transited by Steel-concrete combining section. The special structure lead the bridge to complex machenical behavior. The application of the hybrid girder cable-stayed bridge with such main girder cross section form in high way bridges is not common,mechanical characteristics of the bridge and its steel-concrete joint section were researched in this paper, conquered results as follows:1. The spatial finite element model of Yangpu Bridge’s full bridge was established by adopting Space Plate-Beam method, analysed the mechanical characteristics under dead load, worst-case of living load, temperature load, wind load, and loads combination. The computation showed that every constructional element of the bridge characterized by reasonable stressing and satisfied the demands of strength and rigidity.2. The mechanical characteristicss of main girder and floor system with or without consideration of confuses soil creep effect were comparatively analysed respectively. The comparation demonstrated that the relative stiffness of floor system reduced with consideration of confuses soil creep effect, the steel main girder beared greater percentage inner force and its innerstress increased while the inner force of floor system decreased.3. Established refined spatial finite element model of the steel-concrete joint section, analysed and studied the mechanical characteristics, which indicated that under every kind of operate condition, all the steel elements and concrete structure were compressed in axial direction of the bridge; The stresses of steel members and concrete were less than design value with large capacity; The stresses in steel and concrete of the steel-concrete joint section were relatively small; The force transmission between Steel-concrete joint section and pure steel segment in the right was relatively smooth, the stress concentrate phenomenon was not fierce in the joint of Steel-concrete combination and pure steel segment or that of steel-concrete combination and concrete segment.4. Researched the mechanical characteristics of the steel-concrete composite section under Overload condition (dead load+1.6 times axial compression under worst-case of living load), which told that the stresses of steel gider were all less than-170MPa in the steel-concrete composite section or the most 1.6m right of the composite section region; The stress of concrete was less than design value-22MPa in the steel-concrete composite section or the most 3m left of the composite section region, which showed that the steel-concrete composite segment had enough bearing capacity.The research has provided analysis for the design of Hainan Yangpu Bridge and has reference value for studying hybrid girder cable-stayed bridges.更多还原