大跨度桥梁扁平钢箱梁的构造特点和受力特性

扁平钢箱梁具有新颖的结构特点和优良的受力性能，已成为现代大跨度桥梁加劲梁的主要结构形式。本文分析、归纳了扁平钢箱梁的构造特点，并对扁平钢箱梁的受力特性进行探讨。     

大跨度桥梁施工技术的要点分析

桥梁建设已成中国制造的又一张名片。近年来,在我国水域和高速公路上,各种桥梁纷纷建戍,桥梁形式千姿百态,为人们出行提供更加便捷的通道。目前,我国建造的大跨度桥梁数量已经占据了全球一半以上,桥梁建设工程已稳步跨入世界先进行列。论文就现阶段我国大跨度桥梁施工技术中的要点进行简要分析。     

大跨度环形钢箱梁立交桥施工技术

在城市桥梁工程中,钢箱梁结构由于其整体性能好、抗弯抗扭刚度大,现已成为桥梁设计中常用的结构形式。但随着桥梁跨度的增加,形式的多变以及道路交通环境的日趋复杂,其施工吊装成为主要难题,本文针对实际的工程案例,提出了钢箱梁桥分块吊装方法,解决了相应的技术难题,为类似工程提供参考和借鉴。     

跨高速公路钢箱梁安装施工技术

钢箱梁具有拼装快、自重轻、跨度大等特点,在公路桥梁工程中越来越受到重视。本文结合常溧高速C匝道跨扬溧高速钢箱梁施工实例,探讨了跨越高速公路钢箱梁施工的关键技术,从架设方案、钢箱梁加工、交通组织和高速公路安全防护等方面进行了论述,为今后类似桥梁的架设施工提供参考。     

大跨度钢箱梁养护与危害成因分析

钢箱梁是大跨度桥梁的主要结构,对于桥身固定具有重要作用,在国内,由于养护经验不足,对钢箱梁病害认识较少的现象,导致被损坏的想象十分常见。本文就大跨度钢箱梁养护与危害成因进行分析探讨,以供参考。     

小单元制作工艺在钢结构桥梁中的应用和发展

随着我国经济的高速发展和钢结构桥梁设计、制造、施工等方面技术的日益成熟与发展,钢结构桥梁已广泛应用铁路、公路、公铁两用桥及人行天桥。钢箱梁是最常用的结构形式,钢箱梁箱体内部零部件较多,内部焊缝众多,如何保证箱体内部焊接质量及改善作业环境成为需要解决的紧迫问题,根据钢箱梁的特点催生了小单元制作工艺。     

沪青平同三高架立交桥钢箱梁的制作

钢箱梁在高等级公路跨度较大的桥梁孔应用较多,其制作施工要求较高,该文具体介绍钢箱梁在选材、制作、焊接等的施工工艺、施工方法及注意事项、验收标准,以使钢箱梁的制作获得较好的效果。     

九圩港大桥工程连续钢箱梁设计

九圩港大桥主桥跨越南通市九圩港河,采用了三跨变高度连续钢箱梁方案,跨度布置为（50＋80＋50）m。介绍变高度连续钢箱梁的设计思路、构造特点、铺装、防腐涂装要求以及架设方法。此类型的连续钢箱梁桥具有可工厂化制造、吊装重量轻、施工时间短以及对交通和航道影响小等优越性,特别适用于跨越较窄的河道、城市跨线以及工期要求紧张的桥梁。设计方法对类似桥梁的设计有一定的借鉴意义。     

大跨度桥梁钢箱梁疲劳裂纹特征分析及检测技术研究

本文总结了大跨度桥梁钢箱梁疲劳裂纹相关资料,研究了钢箱梁疲劳裂纹检测方法,制作疲劳裂纹标准开裂试件,采用超声波进行检测研究,并结合某长江公路大桥实桥裂纹检测实验。     

临时支墩在钢箱梁施工中的应用

钢结构箱梁具有强度高、自重轻、跨度大、施工速度快、抗震性能好等优点,广泛应用于城市、铁路大跨度桥梁的施工中。现以合合肥市望江路立交桥钢箱梁施工实践,主要介绍大跨度钢箱梁施工过程中临时支墩的设置及施受力验算,供同类项目施工参考。     

Super-long span bridges

Bridges can be categorised by span lengths, such as short-span, medium-span, long-span and super-long-span and also by type, such as girder bridges, arch bridges, cable-stayed bridges and suspension bridges. This paper studies how long a span for each of these four types of bridges can be.     

Investigation of Live Load Deflection Limit for Steel Cable Stayed and Suspension Bridges

Long span bridges such as steel cable stayed and suspension bridges are usually more flexible than short to medium span bridges and expected to have large deformations. Deflections due to live load for long span bridges are important since it controls the overall heights of the bridge for securing the clearance under the bridge and serviceability for securing the comfort of passengers or pedestrians. In case of sea-crossing bridges, the clearance of bridges is determined considering the height of the ship master from the surface of the water, the trim of the ship, the psychological free space, the tide height, and live load deflection. In the design of bridges, live load deflection is limited to a certain value to minimize the vibrations. However, there are not much studies that consider the live load deflection and its effects for long span bridges. The purpose of this study is to investigate the suitability of live load deflection limit and its actual effects on serviceability of bridges for steel cable-stayed and suspension bridges. Analytical study is performed to calculate the natural frequencies and deflections by design live load. Results are compared with various design limits and related studies by Barker et al. (2011) and Saadeghvaziri et al. (2012). Two long span bridges are selected for the case study, Yi Sun-Sin grand bridge (suspension bridge, main span length?=?1545 m) and Young-Hung grand bridge (cable stayed bridge, main span length?=?240 m). Long-term measured deflection data by GNSS system are collected from Yi Sun-Sin grand bridge and compared with the theoretical values. Probability of exceedance against various deflection limits are calculated from probability distribution of 10-min maximum deflection. The results of the study on the limitation of live load deflection are expected to be useful reference for the design, the proper planning and deflection review of the long span bridges around the world.     

Frontier of continuous structural health monitoring system for short & medium span bridges and condition assessment

It is becoming an important social problem to make maintenance and rehabilitation of existing short and medium span(10-20 m) bridges because there are a huge amount of short and medium span bridges in service in the world. The kernel of such bridge management is to develop a method of safety(condition) assessment on items which include remaining life and load carrying capacity. Bridge health monitoring using information technology and sensors is capable of providing more accurate knowledge of bridge performance than traditional strategies. The aim of this paper is to introduce a state-of-the-art on not only a rational bridge health monitoring system incorporating with the information and communication technologies for lifetime management of existing short and medium span bridges but also a continuous data collecting system designed for bridge health monitoring of mainly short and medium span bridges. In this paper, although there are some useful monitoring methods for short and medium span bridges based on the qualitative or quantitative information, mainly two advanced structural health monitoring systems are described to review and analyse the potential of utilizing the long term health monitoring in safety assessment and management issues for short and medium span bridge. The first is a special designed mobile in-situ loading device(vehicle) for short and medium span road bridges to assess the structural safety(performance) and derive optimal strategies for maintenance using reliability based method. The second is a long term health monitoring method by using the public buses as part of a public transit system (called bus monitoring system) to be applied mainly to short and medium span bridges, along with safety indices, namely, “characteristic deflection” which is relatively free from the influence of dynamic disturbances due to such factors as the roughness of the road surface, and a structural anomaly parameter.     

地震作用下大跨度悬索桥纵向破坏模式研究

地震作用下结构破坏模式研究是合理保证结构震后安全性的基础,而目前对大跨度悬索桥破坏模式的研究还很少。在大跨度悬索桥中,主缆、加劲梁、吊索等构件组成柔性悬吊体系一般采用钢结构,而主塔为核心支撑构件,且目前在我国修建的大跨度悬索桥中,基本都是门式或框架式的钢筋混凝土桥塔。因此,地震破坏模式的研究重点为大跨度悬索桥的钢筋混凝土桥塔。借助大型有限元分析程序,以润扬大跨度悬索桥的设计方案为背景,对地震作用下大跨度悬索桥纵向破坏模式及其特征展开探讨,发现其桥塔地震破坏模式为具有同时性特征的双塑性铰破坏模式,此失效模式表明此时塑性铰依次形成机制不存在,其屈服后的塑性性能是否能如中小桥梁一样被大幅利用以及如何利用,应由桥塔的塑性动力稳定决定。     

京沪高速铁路南京长江大桥斜拉桥方案车桥系统振动分析

提出了列车、大跨度钢桁梁斜拉桥空间振动的有限单元分析模型,采用计算机模拟方法,计算了列车以不同车速通过该大跨度斜拉桥的空间振动响应,检算该桥是否具有足够的横向、竖向刚度及良好的运营平稳性,所得结果可供设计参考。     

结构健康监测和可靠性评估

对美国最大跨度桁架桥中的主要桁架构件以及整个结构系统的可靠性进行评估。根据构件和系统的可靠性指标,可以采用随机方法评估大跨桥的安全水平。然而,大多数旧的大跨桥是基于允许应力设计的,其可靠性不可能被保证。本研究的可靠性分析基于对恒荷载、活荷载和风载分布的评估。通过收集大量的输入和响应数据,对大桥进行长期结构健康监测。根据外部荷载影响的模式和大小,长期监测数据清楚揭示了不同结构的性能。案例显示,采用传统的分析方法难以确定由于温度引起的结构响应。为探讨温度对结构的影响以及在可靠性评估中考虑长期监测数据的作用,也对温度引起的响应进行分析。研究显示：温度导致的响应对整个系统的可靠性具有明显的影响。     

PC箱梁桥非均匀收缩变形分析

大跨预应力连续刚构桥后期超限下挠问题,越来越受到工程界的普遍关注。文中以湿度扩散理论为基础,研究PC箱梁结构非均匀收缩变形计算方法。针对某实桥典型截面建立二维湿度场分析有限元模型,分析箱梁截面二维湿度场分布规律及时变特征。根据湿度场变形耦合条件研究连续刚构桥主梁干缩变形行为特点。结果表明,PC箱梁结构非均匀收缩变形显著,常规方法计算误差较大。考虑箱梁截面非均匀收缩因素后,跨中下挠累计值较常规方法大3.1 cm,表明箱梁截面的不均匀收缩是引起连续刚构桥后期超限下挠的重要原因。     

建立大跨度桥梁首级平面工程控制网的研究

针对大跨度桥梁施工测量的技术要求 ,从桥梁工程建设出发 ,分析大跨度桥梁施工中的基本施工测量精度 ,得出大跨度桥梁的首级平面工程控制网的必要精度。提出建立特大型桥梁的首级工程控制网基本网型 ,并采用工程测量控制网优化设计程序 ,分析不同跨江宽度的设计精度。通过近几年一些大跨度桥梁的首级平面工程控制网的实例 ,证实了建立大跨度桥梁首级平面工程控制网可达到设计精度 ,并得出一些有价值的结论     

Reliability analysis of long span steel arch bridges against wind-induced stability failure

An efficient method for reliability assessment of long span steel arch bridges against wind-induced stability failure is presented in this paper. The prediction of wind-induced stability of such bridge structures is performed by an eigenvalue method and the reliability estimates are determined by a generalized first-order reliability algorithm. A software strategy for interfacing the present method with ANSYS is developed via a freely available MATLAB software tool (FERUM). A numerical example involving a detailed computational model of a long span steel arch bridge with a main span of 550 m is presented to demonstrate the applicability and merits of the present method and the software strategy. Finally, the most influential random variables on the reliability of long span steel bridges against wind-induced stability failure are identified by a sensitivity analysis.     

正交异性钢桥面板纵肋与桥面板连接细节的疲劳评估及修复措施

正交异性钢桥面板由于具有自重轻、极限承载力大等优点目前广泛应用于大、中跨径桥梁中,我国已建和在建的大跨径桥梁也大多采用正交异性钢桥面板.但由于正交异性钢桥面板结构构造复杂,受焊接残余应力影响大,钢桥面板直接位于车轮荷载的作用下,一些构造细节处极易发生疲劳开裂.以国内某大桥正交异性钢桥面板为例,针对纵肋与桥面板之间的疲劳...