自锚式斜拉—悬索协作体系桥发展研究

随着交通科技的发展,各种类型的大跨径斜拉桥及大跨径悬索桥层出不穷。但由于力学体系和材料等要求,斜拉桥和悬索桥的跨径都受到多种原因的限制,而自锚式斜拉-悬索协作体系桥梁则可以解决其中不少问题。本文结合工程实际将自锚式斜拉-悬索协作体系桥梁与斜拉桥和悬索桥进行对比,从历史和现状等方面进行探讨研究,提出其存在的问题,对未来进行展望。     

山坡锚固式超大跨径空间缆索人行悬索桥探讨

为了降低峡谷景区超大跨径人行悬索桥的造价，提出一种山坡锚固式空间交叉网缆索体系的人行悬索桥。在峡谷景区两侧岩石山坡体之上，分散锚固马鞍抛物面空间交叉网缆索体系，取消桥塔结构，降低造价。相比左右两根互相分离的平行缆索体系，马鞍抛物面空间交叉网缆索体系可以产生水平向的分力，解决了人行悬索桥的大幅度侧向摆动问题，提高了峡谷景区人行悬索桥的抗风稳定性。结合某500 m级峡谷景区超大跨径人行悬索桥工程，开展动力模态分析，以便验证山坡锚固式空间缆索体系人行悬索桥的优越性。     

大跨径悬索桥力学性能研究

悬索桥由于其优美的结构和宏伟的规模成为大跨径桥梁的主要型式之一。这里根据具体的大跨径悬索桥工程实例,结合有限元模型,对桥梁进行力学分析。通过分析桥梁的受力特点,研究在竖向荷载静力作用的情况下大跨径悬索桥的力学性能。希望对类似工程起到积极的借鉴作用。     

人行悬索桥颤振性能风洞试验及气动稳定措施

以某景区大跨度人行悬索桥为背景,采用节段模型风洞试验,分别研究了原设计断面和四类气动措施方案的风致振动性能.结果表明:采用下中央稳定板可以有效提高板式加劲梁人行悬索桥的颤振稳定性,可为类似桥梁断面的设计提供参考.     

矮寨特大悬索桥重力锚基坑开挖技术

矮寨特大悬索桥是1 000 m以上跨径,悬索桥跨峡谷高度世界第一的桥梁,嵌岩式重力锚基坑开挖主要介绍了深孔松动爆破、周边光面爆破、基底清理措施、出渣方案等的成功经验。     

汕湛高速公路西江特大桥猫道施工关键技术

随着桥梁修建技术的发展,悬索桥的跨径不断增大。猫道作为大跨径悬索桥施工必备的临时结构,为主缆架设、索夹和吊索安装、钢箱梁吊装、主缆防护等提供施工操作平台、材料及工具运输通道,从始至终贯穿整个悬索桥上部构造安装施工过程。以西江特大桥猫道作为研究对象,对其结构设计、施工过程及关键技术展开详细介绍,并对实际施工过程中出现的问题提出优化措施。     

大跨径悬索桥自振特性及其参数分析

以某公路悬索桥为例,介绍了大跨径悬索桥自振特性,运用三维有限元程序,对悬索桥动力特性参数进行了分析,并提出影响大跨径桥梁自振特性的主要设计参数。     

拱型中央扣对大跨径马鞍面空间索网悬索桥动力模态影响

在超大跨径马鞍面混合空间缆索悬索桥基础上,提出一种刚柔并济的提篮拱状钢管混凝土拱型中央扣结构方案,以提高超大跨径悬索桥结构的空间刚度.结合规划中的5000m级琼州海峡大桥,建立ANSYS有限元分析模型,开展提篮拱状钢管混凝土拱型中央扣对马鞍面空间索网悬索桥动力模态特性影响研究.研究表明:提篮拱状钢管混凝土拱型中央扣代替...     

城市桥梁建设——美国

本文主要介绍美国经典的城市大跨径桥梁（悬索桥、拱式桥和斜拉桥）、具有创新理念的两座新世纪大跨径桥梁及相关启示和建议。     

大跨度稳定型悬索桥力学性能分析

近年来悬索桥已成为大跨桥梁的首选桥型,而稳定型悬索桥作为普通悬索桥的优化结构,势必将在大跨径领域有广泛发展,因此研究大跨度稳定型悬索桥的力学特性具有十分重要的意义。首先建立稳定型悬索桥和与之相应的普通悬索桥,并对两者进行了多项力学性能分析对比,研究了静力特性、动力特性、地震响应振动特性。藉此确定大跨度稳定型悬索桥的力学特性,相比较结果可得大跨度稳定型悬索桥各方面力学性能要明显优于大跨度普通悬索桥。     

Aerodynamic challenges in span length of suspension bridges

The potential requirement of extreme bridge spans is firstly discussed according to horizontal clearances for navigation and economical construction of deep-water foundation. To ensure the technological feasibility of suspension bridges with longer spans, the static estimation of feasible span length is then made based on current material strength and weight of cables and deck. After the performances of the countermeasures for raising the aerodynamic stability are reviewed, a trial design of a 5 000 m suspension bridge, which is estimated as a reasonable limitation of span length, is finally conducted to respond to the tomorrow’s challenge in span length of suspension bridges with the particular aspects, including dynamic stiffness, aerodynamic flutter and aerostatic stability. Selected and modified from Proceedings of the 11th International Conference on Wind Engineering, 2003, 65–80     

Parametric study on the aerodynamic stability of a long-span suspension bridge

The aerodynamic stability becomes a governing factor in designing long-span suspension bridges. In this paper, using the method of three-dimensional nonlinear aerodynamic stability analysis, parametric analyses on the aerodynamic stability of the Runyang bridge over the Yangtze River are performed including the structural system, the cable sag, the side span length, the depth, dead load and supporting system of the deck, etc. Some important design parameters that affect the aerodynamic stability of the bridge are pointed out, and the favorable structural system of the bridge is also discussed based on the wind stability.     

Aerodynamic stability of cable-stayed bridge with new Vierendeel-type girder

An aerodynamic study is described showing the stability of a new type of double deck cable-stayed bridge having both upper and lower flat, shallow, streamlined box girder decks connected by vertical members only. In long span, cable-stayed bridges the longer the span, the more important the aerodynamic stability of the structure becomes. Even though cable-stayed bridges evidence structural damping, the measure of the aerodynamic stability of such a bridge is whether or not a cross-sectional shape of the suspended structure is stable against flutter oscillation and vortex-excited oscillation. The experiments presented in this paper, therefore, focus on the aerodynamic stability against these phenomena in a partial scale model of a cable-stayed bridge of new design. The three aerodynamic components of force have also been measured. For comparison, a wind-tunnel experiment has been carried out using a partial model of a conventional suspended structure of a typical truss type double deck cable-stayed bridge. It is shown that the new system is superior to the truss type from an aerodynamic stability viewpoint.     

Investigation on aerodynamic stability of long-span suspension bridges under erection

The aerodynamic stability of long-span suspension bridge under erection, particularly at early erection stage, is more problematic than in the final state. It is influenced by the deck erection sequence and the nonlinear effects of wind-structure interactions. Considering the geometric nonlinearity of bridge structures and the nonlinear effects of wind-structure interactions, a method of nonlinear aerodynamic stability analysis is presented to predicate the aerodynamic stability limit (flutter speed) of long-span suspension bridges during erection. Taking the Yichang Bridge over the Yangtze River as example, evolutions of flutter speeds with the deck erected by different sequences are numerically generated. The sequences of pylons to midspan and the non-symmetrical deck erection are confirmed analytically to be aerodynamically favorable for the deck erection of long-span suspension bridges, particularly at early erection stages. The flutter speeds of long-span suspension bridges under erection are greatly decreased by the nonlinear effects of wind-structure interactions.     

应用碳纤维缆索的大跨度悬索桥抗风稳定性研究

为了探讨碳纤维复合材料缆索在大跨度悬索桥中应用的可能性,以主缆等轴向刚度为原则,拟定了一座主跨为1490m的碳纤维复合材料主缆悬索桥,并运用三维非线性计算理论进行了空气静力和动力稳定性分析。通过与同跨度钢主缆悬索桥的比较,讨论了不同主缆材料对大跨度悬索桥抗风稳定性的影响。分析结果表明:大跨度悬索桥采用碳纤维复合材料主缆后,静风作用下结构的变形增大,但其静风稳定性却与钢主缆悬索桥基本接近;由于结构自振频率特别是扭转频率有显著的提高,使得其空气动力稳定性要比钢主缆悬索桥好。因此从抗风稳定性角度而言,大跨度悬索桥采用碳纤维复合材料主缆是可行的,但是主缆截面尺寸的确定应采用等轴向刚度的准则。     

Influence of some factors on the aerodynamic behavior of long-span suspension bridges

As the span length of suspension bridges increases, the diameter of cables and thus the wind load acting on them, the nonlinear wind-structure interaction and the spatial non-uniformity of wind speed (including the vertical and horizontal variations) all increase consequently, which may have unnegligible influence on the aerostatic and aerodynamic behavior of long-span suspension bridges. In this paper, the models of aerostatic and aerodynamic forces are established, in which the nonlinear wind-structure interaction and the spatial non-uniformity of wind speed are both considered. By taking the Runyang Bridge over the Yangtze River as example, effects of the nonlinear wind-structure interaction, wind speed spatial non-uniformity, and the cable's wind load on the aerostatic and aerodynamic behavior of the bridge are investigated analytically. The results show that the aerostatic behavior is significantly influenced by these factors, but for the aerodynamic stability, it is greatly influenced by the nonlinear wind-structure interaction and the horizontal variation of wind speed, and the other factors have no influence on it.     

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。     

State-of-the-art of long-span bridge engineering in China

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.     

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     

洪都大桥单索面自锚式悬索桥设计构思

洪都大桥是南昌市城区跨越赣江的第5座大桥,由南主桥、北主桥、南北接线、杨子洲高架等组成,全长为9.5km。南主桥主航道桥采用主跨195m双塔单索面自锚式悬索桥。着重介绍单索面自锚式悬索桥结构中主梁、主塔、基础、缆索系统的设计和结构性能分析。最后介绍了顶推施工方法。该桥已于2009年3月正式建成通车。