吊桥颤振临界风速计算

从历史诸多座吊桥塌坍事故中汲取教训,分析吊桥毁桥原因为风速达到颠振临界风速所致,介绍吊桥颤振临界风速的实用计算法,并与实桥风洞试验结果进行了对比.     

某景区人行吊桥的检测

人行吊桥由于构造简单,造价低廉,常用于景区道路中。如何确保吊桥安全使用直接关系到游客的人身安全。以某景区人行吊桥为例,探讨了吊桥的检测内容和相应的检测方法,为该类桥梁的检测提供了一定的借鉴。     

某人行索桥方案研究

通过对钢箱梁斜拉桥及钢箱梁吊桥两个方案的综合比选,确定采用钢筋吊桥方案,并对桥梁的总体布置要求进行了介绍,主要阐述了钢梁、主缆及吊索等结构设计要点,为同类桥梁设计选型提供了参考。     

某博物馆室内之形吊桥结构体系设计与施工技术

室内之形吊桥结构跨度大、结构形式新颖,采用此类新型的吊桥结构体系不仅在公共建筑的形式上得到创新,同时也在结构设计及施工技术方面有了新突破。通过室内之形吊桥结构施工技术在蚌埠三馆工程中的成功应用,总结了施工吊桥的经验。     

吊桥主索施工技术

吊桥，又名悬索桥，随着我国公路桥梁施工的日益增多，吊桥的施工技术也成了热门课题。本公司承担的某市河心公园吊桥主索施工，由于受河岸限制，吊桥主索跨度较大，且施工场地狭小，故不能按一般常规的办法进行主索架设，而是由主索、吊索、桥面梁系、索塔、索鞍等几部分组成。如图１主索采用６×３７Ｓ＋ＩＷＲ－１６７０－５２钢芯镀锌钢丝绳，抛物线方程为Ｘ２＝２×１２５５２５Ｚ。现介绍其施工技术，供参考。图１某市河心公园吊桥示意图１主要钢绳的购置长度１．１主要钢绳中段抛物线的弧线长的计算抛物线的长度可按下式进…     

吊桥颤振临界风速计算

从历史诸多座吊桥塌坍事故中汲取教训,分析吊桥毁桥原因为风速达到颤振临界风速所致,介绍吊桥颤振临界风速的实用计算法,并与实桥风洞试验结果进行了对比。     

渝东山区人行吊桥设计及其应用研究

在搜集整理有关渝东山区人行吊桥技术资料的基础上,根据我国现行桥梁规范,对人行吊桥主要技术参数及其构造进行了分析和评价,指出在设计人行吊桥时既要考虑桥梁本身的安全性、适用性、耐久性,又要从山区经济实际出发,尽量节约造价。     

浅谈吊桥舒适度影响效应

人行吊桥在行人荷载作用下导致人桥共振现象会让行人在生理和心理上产生不舒服的感觉,本文以三风镇水库吊桥为工程背景,浅析人行作用激励下的振动响应对吊桥舒适性影响。     

室内“之”形吊桥结构振动试验和舒适度评价研究

通过蚌埠市博物馆室内"之"形吊桥新型结构体系的振动试验和舒适度评价试验,掌握了吊桥与行人荷载间关系的规律,确定了室内"之"形吊桥舒适度评价指标,填补了国内外空白,为该类结构的设计、施工与运营提供了科学依据。     

浅析人行吊桥技术

现在交通路网已经逐步形成,然而专供人行的吊桥却用得较少,其多为旅游景区作为景点和娱乐在使用。随着城镇化的发展,行人有往来城镇河流两岸的需求,因而人行吊桥仍有应用的前景。因为人行吊桥的跨径变化灵活,技术简单,造价较低,在城镇化建设的进程中势必受到青睐。但从人行吊桥的安全性、耐久性考虑,其使用的材料、施工方法、防护技术都有提升的空间,值得去研究改进。     

混合式桥型对超长跨桥梁的适应性

本文对中跨为2500m的混合型斜拉悬索桥的进行了初步设计,构想了三种斜拉悬索桥和一种悬索桥桥式。从初步设计结果中比较它们上部结构钢材的重量发现,考虑到下部结构尺寸,斜拉悬索桥相对悬索桥具有优越性。另外,对这几种型式的桥梁进行了抗弯稳定性分析以及耦合颤振分析。分析结果表明,斜拉悬索桥抗弯稳定性是足够的,而且其临界风速高于悬索桥的临界风速。所以,作者认为针对超长跨度桥梁混合型斜拉悬索桥赛过悬索桥     

中塔纵向刚度对三塔缆索承重桥静力特性影响

简述三塔斜拉桥和三塔悬索桥的静力特性,提出三塔斜拉一悬索协作体系桥梁,用ANSYS软件对三塔缆索承重桥梁各体系建立三维有限元模型,分析比较各体系的静力特性及讨论中塔纵向刚度对各体系结构性能的影响。     

System reliability of suspension bridges

Provisions for the design of existing suspension bridges often rely on a deterministic basis. Consequently, the reliability of these bridges cannot be assessed if current provisions are applied. In order to develop cost-effective design and maintenance strategies for suspension bridges a system reliability-based approach has to be used. This is accomplished by a probabilistic finite element geometrically nonlinear analysis approach. This study forms part of an investigation into the system reliability evaluation of geometrically nonlinear large span bridges recently undertaken at the University of Colorado. A brief review of reliability analysis of geometrically nonlinear elastic structures allows for the determination of its relevance to the assessment of suspension bridges. A probabilistic finite element geometrically nonlinear elastic code is used for system reliability evaluation of suspension structures. The allowable stress design procedures used by the Honshu Shikoku Bridge Authority for the design of suspension bridges are presented along with their application to the design of an existing bridge. This bridge is studied from a system reliability viewpoint to evaluate its reliability under different loading and damage scenarios. Such information calls attention to the fact that the reliability of cables, hanger ropes and girders are very different. Therefore, optimal maintenance decisions for suspension bridges designed according to allowable stress method are not consistent with those based on equal component reliability values.     

辅助结构对悬索桥的颤振稳定性的影响

随着悬索桥跨度不断增加,风荷载引起的稳定性问题在悬索桥的设计过程中的地位越来越重要,探求具有优异结构性能的悬索桥结构形式成为一项极有意义的工作,本文旨在研究在传统悬索桥基础上增加辅助结构之后悬索桥自振特性的变化,并寻求提高悬索桥颤振临界风速的有效措施。     

大跨度自锚式悬索桥的动力特性分析

以钱江九桥和青岛海湾桥大沽河航道桥两座自锚式悬索桥为例,用通用有限元软件ANSYS建立了大桥的三维有限元动力计算模型,对大桥进行了静力和动力计算分析,发现存在多阶拉索振动振型并对此现象进行了分析,为大跨度自锚式悬索桥的设计、施工提供了参考。     

Further studies on the stability of suspension bridges in random winds

The problem of aeroelastic stability of suspension bridges in random winds is studied. The criteria for almost sure stability of the equilibrium state of suspension bridges in stationary random winds are obtained and the established results are verified by a direct comparison with those of the available wind tunnel tests on models of the suspension bridges under investigation in this work.     

Long-span cable-supported bridges: general review

It has been said that ‘Temples and bridges are the most outstanding exhibits of mankind’. On the other hand, there has never been so many notable long-span bridges been built as during the change of the millennium. The boom of great bridges concerns long-span cable-supported bridges, i.e. suspension bridges and cable-stayed bridges, particularly in China. In this short essay, a collection of longest cable-supported bridges is presented.     

悬索桥基准索股的空缆状态

本文首先分析了影响悬索桥主缆线形的各种因素,然后采用精确的悬索桥缆索系统分析程序,对两座典型悬索桥的主缆线形进行了计算分析,比较了成缆空缆状态与基准索股空缆状态,得出了一些有意义的结论,供设计和施工时参考。     

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.     

基于挠度理论的三塔悬索桥参数分析

采用多塔悬索桥挠度理论,对三塔悬索桥的矢跨比、主塔刚度、加劲梁高度和主塔高差等进行了参数分析。通过这些分析,有利于帮助人们把握三塔悬索桥的受力特点,得出的结论可供类似桥梁方案设计时参考。