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单索面钢-混凝土组合箱形截面斜拉桥由于存在索力传递效应、箱形截面扭转畸变、剪力滞效应等使其空间受力特征显著,所以如采用“传统1D杆系模型+横向框架模型”的设计理论,将会忽略桥面板面内水平剪应力,导致工程实践中桥面板斜向开裂病害发生。JTG 3362—2018《公路钢筋混凝土及预应力混凝土桥梁设计规范》提出设计应关注箱形截面的空间应力体系。基于新规范提出的基于平面应力的板单元结构设计方法,并将其应用于上海市昆阳路闵浦三桥斜拉桥混凝土桥面板的承载力配筋设计中。结果表明,基于平面应力的板单元结构设计方法与完整空间效应下的混凝土桥面板受力特征相吻合,能够准确识别结构重点关注的桥面板位置,并有效防止桥面板斜向开裂等病害的发生,从而可以指导钢-混凝土组合断面桥梁的混凝土桥面板配筋设计。 相似文献
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枝城、九江和南京等公铁两用桥升级改造的不断开展,标志着我国首批公铁两用桥梁维修周期的到来,而上述桥梁改造的主要内容为将原公路混凝土桥面板更换为正交异性钢桥面板。新制桥面板因其结构特点,单体尺寸较宽、质量较大,同时受空间、既有结构等多种边界条件限制,传统的架设方法、安装工艺等均无法使用。结合九江长江大桥升级改造桥面板架设安装施工,重点对公铁两用桥宽体桥面板架设安装技术进行研究。 相似文献
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Huating CHEN Xianwei ZHAN Xiufu ZHU Wenxue ZHANG 《Frontiers of Structural and Civil Engineering》2022,16(10):1336
An innovative composite deck system has recently been proposed for improved structural performance. To study the fatigue behavior of a steel-concrete composite bridge deck, we took a newly-constructed rail-cum-road steel truss bridge as a case study. The transverse stress history of the bridge deck near the main truss under the action of a standard fatigue vehicle was calculated using finite element analysis. Due to the fact that fatigue provision remains unavailable in the governing code of highway concrete bridges in China, a preliminary fatigue evaluation was conducted according to the fib Model Code. The results indicate that flexural failure of the bridge deck in the transverse negative bending moment region is the controlling fatigue failure mode. The fatigue life associated with the fatigue fracture of steel reinforcement is 56 years. However, while the top surface of the bridge deck concrete near the truss cracks after just six years, the bridge deck performs with fatigue cracks during most of its design service life. Although fatigue capacity is acceptable under design situations, overloading or understrength may increase its risk of failure. The method presented in this work can be applied to similar bridges for preliminary fatigue assessment. 相似文献
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This paper proposes a new type of steel-concrete composite deck, which is composed of orthotropic steel deck (OSD) with T-shaped ribs, concrete plate and studs connecting OSD and concrete plate. The OSD can act as framework for concrete plate and contribute to load bearing capacity at the same time, which could save construction time. Compared with conventional OSD system, this new type of composite bridge deck can also improve fatigue performance.Considering that this type of composite deck is not yet applied in practical engineering and its mechanical performance is not revealed in previous literatures, two full-scale specimens were designed and manufactured in this research. The mechanical performance, particularly, bending capacity in positive and negative region was carefully tested and analyzed. The load-deflection curve, load-slip relation, strain distribution in concrete and steel were obtained. The test results showed that the plastic performance of this kind of composite bridge deck was satisfying and the bending capacity was high. 相似文献
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This paper introduces the state-of-the-art of longspan bridge engineering in China with emphases on recent long-span bridge
projects, bridge deck configuration and material, design codes of long-span bridges and improvement of aerodynamic performance.
The recent long-span bridge projects include thirty-eight completed suspension bridges, cable-stayed and arch bridges with
a main span over 400 m, and eighteen major bridges are under construction. The bridge deck configuration and material, with
prestressed concrete decks, steel-concrete composite decks and steel box decks together with several popular cross-sections,
are presented. The third part briefly outlines four design codes, including static and dynamic design for highway long-span
bridges, and the recent engineering experiences gained from several aerodynamic vibration control projects of long-span bridges
are shared in the last part. 相似文献
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为从根本上解决混凝土桥、钢桥及钢 混凝土组合桥中的共性技术难题,并提升桥梁结构的性能与品质,笔者团队以超高性能混凝土(UHPC)为基础,研发了面向未来的高性能桥梁结构体系。介绍了笔者团队研发的4类高性能桥梁结构:①钢-超高韧性混凝土(STC)轻型组合桥面结构,其中的STC是钢桥面专用的UHPC;②钢 UHPC华夫板轻型组合桥梁结构;③单向预应力UHPC薄壁连续箱梁结构;④全预制快速架设UHPC城市桥梁结构。通过大量静力和疲劳试验,掌握了各类UHPC桥梁结构的基本受力性能,并建立了计算理论和设计方法。列举了钢 STC轻型组合桥面结构已推广应用于中国的17座钢桥,涵盖了梁桥、拱桥、斜拉桥和悬索桥等各类基本桥型,典型应用包括湖南岳阳洞庭湖二桥等重大工程。到目前为止,各实桥运营状态良好,钢 STC未出现任何病害问题。综合而言,高性能桥梁结构有望突破现有桥梁中的技术瓶颈,具有广阔的应用前景。 相似文献
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以山西漪汾桥为例,对正交异性钢桥面与结合梁方案进行了对比,阐述了两者的优缺点,比较发现钢-混凝土组合梁能充分发挥钢材与混凝土这两种材料的优势,且钢梁架设计完成后可作为混凝土结构施工的模板。 相似文献
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开口钢箱叠合梁,开口钢箱在下部,砼桥面板在上部,受力非常合理,其充分利用了钢材抗拉性能和砼抗压性能,而且减轻了桥梁的自重。由于开口钢箱叠合梁安装过程受力复杂,可能会引起砼的开裂,因此开口钢箱叠合梁在安装过程需要验算砼桥面板的应力。该文通过大型有限元软件计算分析,验算2跨连续开口钢箱弯桥在安装过程中是否会开裂。 相似文献
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桁架组合梁桥包括复合桁梁桥和组合桁梁桥。组合桁梁桥是指将一般钢桁梁的上、下弦和混凝土桥面板结合在一起共同受力的结构。通过对奉干公路浦南运河空间组合桁梁桥的有限元计算,分析了空间组合桁梁桥的传力特点,通过桥面板应力分布得到有效宽度,揭示了腹杆轴力与桥面板剪力滞现象之间的关系,为组合桁梁桥的设计提供参考。 相似文献
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对一已建二级公路桥梁进行了桥面修补的数值模拟分析,分别采用了钢纤维混凝土、钢纤维混凝土+碳布、环氧混凝土、环氧混凝土+碳布4种修补方案,分析表明:各种修补方案在车道荷载作用下的应力水平远远低于降温20℃工况下的应力水平,温度工况应该是桥面裂缝修补方案更需要关注的工况,得出钢纤维混凝土+碳布修补方案最佳的结论。 相似文献
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介绍了钢纤维混凝土的基本性能,确定了钢纤维混凝土配合比。结合某高速公路大桥工程实例,对其在桥梁桥面铺装施工中的具体问题进行探讨,指出钢纤维混凝土的分散工作、投料顺序、运输和浇筑过程中的注意事项及采取的有效措施。结果表明工程质量良好,营运期维修费较低,延长了使用寿命。 相似文献