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根据安庆长江大桥索梁锚固结构的静载模型试验,对锚箱在索力作用下的受力特征、传力途径、应力分布进行了细致分析并与有限元计算结果比较,得出了一些有益的结论。 相似文献
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大跨度斜拉桥钢锚箱式索梁锚固结构空间有限元模型比较研究 总被引:2,自引:0,他引:2
在进行大跨度斜拉桥钢锚箱式索梁锚固结构空间非线性仿真分析时,有限元模型的正确与否至关重要。由于目前软硬件能力的限制,只能采用锚箱局部模型进行分析,而模型中选取的结构范围及边界条件的不同,都会直接影响锚固区分析结果。通过对不同的有限元模型进行研究比较,得到合理的建模方法,用以判断实际结构中索粱锚固区的安全储备。这种仿真分析可以用于设计选型、锚箱研究及指导模型试验。 相似文献
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对于大跨度钢箱梁斜拉桥而言,需通过索梁锚固结构实现斜拉索与主梁之间的荷载传递。该结构传递荷载大、传力机理复杂、局部应力集中问题突出,是大跨度钢斜拉桥的关键结构和构件之一。以典型的超大跨度斜拉桥——苏通大桥锚箱式索梁锚固结构为研究对象,通过理论研究与试验研究相结合的方法对于锚箱式索梁锚固结构的受力特性进行了研究。研究表明:理论模型与试验结果基本吻合,采用理论研究与模型试验相结合的研究方法对于锚箱结构的传力机理进行研究是可行的;锚箱结构各主要受力构件的受力特性存在较大差异;各关键受力构件均存在不同程度的应力集中,其中钢箱梁腹板、锚箱顶板和底板的应力集中问题较为突出。 相似文献
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鉴于锚箱结构体系及其受力特性的复杂性,以苏通大桥锚箱式索梁锚固结构为研究对象,采用理论研究与模型试验相结合的研究方法,对于锚箱式索梁锚固结构的传力途径、传力机理及其关键影响因素等相关关键问题进行系统研究。研究表明:斜拉索索力作用下锚箱式索梁锚固结构体系受剪力和弯矩的联合作用,并通过锚箱关键受力板件与钢箱梁腹板间的焊缝实现荷载传递,这一受力特性决定了锚箱结构的力学行为特性;由锚箱结构体系的复杂性所决定,不同的设计参数组合将导致其力学特性出现显著差异;锚箱顶底板与钢箱梁腹板的焊缝长度是影响其传力机理的关键因素;各关键影响因素对于锚箱结构力学行为特性的影响具有耦合性,对锚箱结构的传力机理进行系统研究是确定其关键设计参数从而实现其合理结构设计的基本前提。 相似文献
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拉索锚固区是斜拉桥控制设计的关键部位,国内外许多大跨度斜拉桥均对锚固区开展了专门的分析研究。结合工程实例,介绍了大跨度钢箱梁斜拉桥索梁锚固结构的常见连接型式——锚箱式、销铰式、锚拉板式和锚管式。概述了不同连接型式的构造特点及有限元计算、静载试验和疲劳试验方法。分析了四种锚固结构的传力机理和应力集中现象,提出了合理传递索力和减小应力集中现象的构造措施,明确了设计中应注意的问题。 相似文献
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近年来,随着我国钢箱梁技术的成熟以及其设计理论和计算方法的不断提高,再加上其无与伦比的竞争力和适应能力,目前钢箱梁斜拉桥已经在实际中得到了非常广泛的应用。对于钢箱梁斜拉桥来说,索梁锚固区是斜拉索与主梁之间传递力量的重要结构,在对斜拉桥进行设计时,需对这一部分加以特别注意。鉴于此,本文拟从钢箱梁斜拉桥概述、犬跨度钢箱梁斜拉桥索梁锚固结构的型式以及大跨度钢箱梁斜拉桥索梁锚固结构型式的比较等几个方面来进行分析与阐述,以期加深对这一问题的认识与理解程度。 相似文献
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斜拉桥索梁锚固区受力性能复杂,锚拉板作为斜拉索与钢主梁连接的主要受力构件,是全桥控制设计的关键部位。本文对斜拉桥锚拉板式索梁锚固结构空间受力性能进行数值分析,得出了一些有价值的结论,为今后类似工作提供了理论依据。 相似文献
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以安徽省徐明高速公路五河定淮大桥主桥为研究背景,针对大跨度斜拉桥索梁锚固区受力集中、构造复杂、非线性行为突出,利用ANSYS有限元程序建立包含钢箱梁节段的索梁锚固区实体模型,同时考虑材料非线性和接触非线性,实现该局部的空间受力分析。明确索梁锚固区传力途径和可靠性,为设计提供理论依据。 相似文献
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自锚式钢箱梁悬索桥主缆锚固区受力性能研究 总被引:3,自引:0,他引:3
以青岛海湾大桥大沽河航道桥为工程背景,对自锚式钢箱梁悬索桥主缆锚固区受力性能进行研究。主缆力通过锚固区向分体箱的传递可分为两个独立过程,针对这两个过程分别从局部性能和整体性能两个层次进行研究。第一个层次采用模型试验和有限元分析对纯钢和组合两种锚固构造局部受力性能进行研究。纯钢锚固构造应力分布规律复杂,应力集中现象明显,实测结果和有限元分析结果吻合良好。组合锚固构造钢与混凝土有效发挥组合作用,大幅降低钢板应力,减小钢板厚度和钢材用量,使钢板受力更为均匀。组合锚固构造相比纯钢锚固构造实测应力降幅明显,但略小于计算结果,表明钢与混凝土之间发挥部分组合作用,建议采取三方面构造措施以进一步发挥钢与混凝土的组合作用。第二个层次采用有限元分析方法对主缆锚固区整体受力性能进行研究。结果表明,整个过程传力可靠顺畅,安全储备高,符合按杆系模型计算整体结构的假定。 相似文献
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《The IES Journal Part A: Civil & Structural Engineering》2013,6(4):258-269
Finite element (FE) modelling is a prominent way to simulate both static and dynamic characteristics of cable-stayed bridges to understand their structural complexities. Many initial FE models have not been successful in the analysis of the structural behaviour of cable-stayed bridges. This paper presents the details of an updated FE modelling procedure for long-span cable-stayed bridges. The design information of Tatara Bridge with an 850-m main span is considered for numerical studies. The dynamic properties of the FE model, including mode shapes and natural frequencies, are compared with field vibration test results to validate the presented modelling process. Sensitivity analysis of structural parameters is also applied to update effective parameters and understand the structural behaviour of the bridge. The new and beneficial aspects presented in this paper regarding FE modelling procedure and finding effective material and structural parameters will be useful for future design and analysis of cable-stayed bridges. 相似文献
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《Structure and Infrastructure Engineering》2013,9(6):725-739
Accurate evaluation of the effect of possible damage in critical components on the dynamic characteristics of a structure is of critical importance in developing a robust structural damage identification scheme for a long-span cable-stayed bridge. The strategies of finite element (FE) modelling of a long-span cable-stayed bridge for multi-scale numerical analysis are first investigated. A multi-scale model of the Runyang cable-stayed bridge is then developed, which is essentially a multi-scale combination of a FE model for modal analysis of the entire bridge structure and FE sub-models for local stress analysis of the selected locations with respect to the substructuring method. The developed three-dimensional global-scale and local-scale FE models of Runyang cable-stayed bridge achieve a good correlation with the measured dynamic properties identified from field ambient vibration tests and stress distributions of a steel box girder measured from vehicle loading tests, on the basis of which the effectiveness of some damage location identification methods, including a modal curvature index, a modal strain energy index and a modal flexibility index, are evaluated. The analysis results show that the effect of the simulated damage in various components of the steel box girder on the dynamic characteristics of a long-span cable-stayed bridge should be properly considered in structural damage analyses using multi-scale numerical computation. 相似文献
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Steel and steel-concrete composite girders are two types of girders commonly used for long-span bridges. However, practice has shown that the two types of girders have some drawbacks. For steel girders, the orthotropic steel deck (OSD) is vulnerable to fatigue cracking and the asphalt overlay is susceptible to damage such as rutting and pot holes. While for steel-concrete composite girders, the concrete deck is generally thick and heavy, and the deck is prone to cracking because of its low tensile strength and high creep. Thus, to improve the serviceability and durability of girders for long-span bridges, three new types of steel-UHPC lightweight composite bridge girders are proposed, where UHPC denotes ultra-high performance concrete. The first two types consist of an OSD and a thin UHPC layer while the third type consists of a steel beam and a UHPC waffle deck. Due to excellent mechanical behaviors and impressive durability of UHPC, the steel-UHPC composite girders have the advantages of light weight, high strength, low creep coefficient, low risk of cracking, and excellent durability, making them competitive alternatives for long-span bridges. To date, the proposed steel-UHPC composite girders have been applied to 14 real bridges in China. It is expected that the application of the new steel-UHPC composite girders on long-span bridges will have a promising future. 相似文献