苏州云梨桥的结构设计

斜靠式提篮拱桥是一种结构形式较新颖、特点鲜明的组合拱式结构体系,以云梨桥为例,对全钢结构斜靠式提篮拱桥的拱肋、系梁、吊杆、下部结构等设计及施工方案与注意事项作了介绍,可供类似工程参考。     

主要设计参数对斜靠式拱桥地震响应的影响

以某斜靠式拱桥为工程背景,采用有限元软件MIDAS/Civil建立该桥的空间有限元计算模型,分析主要设计参数对斜靠式拱桥地震响应的影响。计算结果表明:斜靠拱与主拱刚度比的变化决定了斜靠拱对该斜靠式拱桥的作用;矢跨比变化对该斜靠式拱桥的顺桥向地震响应影响较大,尤其是对轴力和面内剪力的影响较大;横撑数量减少时,主副拱之间的连接变弱,使其整体性变弱,不仅削弱了斜靠拱对结构的作用,而且不利于斜靠自身受力。尼尔森体系吊杆形式使桥面系与拱肋的连接增强,使主拱肋的轴力变化均匀,同时增加了对桥面系的约束,可适当减小桥面系的位移。     

全钢结构斜靠式提篮拱桥设

斜靠式提篮拱桥是一种结构形式较新颖的、特点鲜明的组合拱式结构体系,本文以云梨桥为例,对全钢结构斜靠式提篮拱桥的拱肋、系梁、吊杆、下部结构等设计及施工方案与注意事项等做了介绍。     

湛河斜靠式拱桥考虑吊杆破断时的稳定性能分析

以跨越平顶山市湛河的斜靠式拱桥为工程实例,采用有限元程序MIDAS/Civil建立该拱桥空间有限元计算模型,考虑不同的吊杆破断情况,进行斜靠式拱桥空间稳定性能分析,对比斜靠式拱桥不同吊杆破断情况与吊杆完好状态下的桥梁稳定性能计算结果。得出结论:各工况对应的桥梁第1阶稳定系数在7.10～7.34之间,满足一般拱桥稳定系数大于4～5的要求;吊杆破断对该桥梁的低阶失稳模态几乎没有影响,失稳形式主要表现为拱肋的面外扭转失稳;主拱吊杆破断对桥梁稳定系数影响较大,稳定拱吊杆破断对桥梁稳定系数影响较小。计算结果对正确认识斜靠式拱桥在不同吊杆破断状态下的稳定性能以及进行斜靠式拱桥的科学维护,具有重要的理论意义及工程实用价值。     

斜靠式拱桥侧倾失稳极限承载能力简化计算方法

以斜靠式拱桥为研究对象,基于Ritz法,首次推导出了拱轴线为抛物线的斜靠式拱桥弹性侧倾失稳临界荷载计算公式,并基于有限元法验证了所提出的斜靠式拱桥发生侧倾失稳时主拱肋与稳定拱肋间横撑切向和径向受力模型的精确性以及所推导的侧倾失稳临界荷载计算公式的正确性。此外为便于估算斜靠式拱桥的侧倾失稳极限承载能力,最先引入了稳定拱肋和横撑影响系数η1、吊杆非保向力和桥面系影响系数η2、几何和材料双重非线性影响系数η3,提出了便于工程实际应用的斜靠式拱桥侧倾失稳极限承载能力的简化计算公式。研究结果表明:(1)稳定拱肋和横撑影响系数的取值范围为1.3～1.5;(2)吊杆非保向力和桥面系影响系数的取值范围为3.3～3.6;(3)几何、材料双重非线性影响系数的取值范围为0.23～0.28;(4)斜靠式拱桥的侧倾失稳极限承载能力一般为单片拱肋弹性承载能力的1～1.5倍。     

斜靠式拱桥侧倾失稳临界荷载解析解

以新型空间拱桥——斜靠式拱桥为研究对象,提出斜靠式拱桥发生侧倾失稳时主拱肋与稳定拱肋间横撑切向和径向受力模型,基于Ritz法,构造桥梁各主要构件的变形能、外力势能以及吊杆非保向力势,首次推导出斜靠式拱桥侧倾失稳临界荷载的解析解,并通过与有限元计算结果比较,验证该解析解计算公式的正确性。进一步分析稳定拱肋、吊杆非保向力、以及主拱肋与稳定拱肋间横撑对斜靠式拱桥侧倾失稳临界荷载的影响。研究结果表明:①增设稳定拱肋可使桥梁侧倾失稳临界荷载提高1.6～1.8倍左右,同时随着稳定拱肋倾角的增加,临界荷载呈增大趋势;②受吊杆非保向力以及桥面系的影响,桥梁侧倾失稳临界荷载可提高约3.5倍左右;③横撑的径向抗弯刚度对斜靠式拱桥侧向失稳临界荷载影响较大。     

金昌路跨运河斜靠式钢箱拱桥总体设计

杭州市金昌路跨运河桥为单跨130m斜靠式钢箱拱桥,横向设4片拱肋,主拱肋铅直布置,副拱肋位于主拱肋外侧,内倾17．5°,由主副拱形成横向稳定体系,主拱不设置风撑。桥面为纵横梁体系、桥面板为正交异性板。桥梁为无系杆拱体系,拱脚水平推力相对较大,综合考虑软土地区的地基加固措施,对拱脚背侧予以处理,有效提高了土体水平抗推能力。     

斜靠式拱桥力学性能分析

以有限元为理论基础,以数值模拟为计算手段,对斜靠式拱桥静力、屈曲、动力特性和反应谱作用等方面进行了分析。拱桥在自重和车道荷载作用下,主拱轴力符合一般拱桥力学概念,斜靠拱受到主拱作用,在拱顶轴力最大。在恒载和使用荷载作用下,拱桥纵向和横向稳定系数值都大于5,满足拱桥稳定性要求。动力特性分析表明,相对于纵向刚度,横向刚度较弱,故在设计和施工中需注意主拱与稳定拱上部连接可靠、变形协调、空间受力一致。斜靠式拱桥在空间三个方向反应谱作用下,主拱在竖向激励下轴力最大,稳定拱为在竖向和横向激励下最大。纵观不同方向作用,纵向刚度较大,而地震作用较小。综合不同方向地震作用,主拱和稳定拱轴力分布规律大致类似于静力作用效果。     

钢结构中承式斜靠拱桥设计

京杭大运河昌运桥主桥采用130 m跨钢结构中承式斜靠拱桥。主拱、副拱均采用变高度钢箱截面以适应拱圈内力变化,主、副拱之间设11道横撑。桥面系采用钢结构“纵横格子梁+正交异性桥面板”的形式。吊杆采用高强度低松弛镀锌平行钢丝索。该桥为有推力体系,推力由大直径群桩基础承担。主桥采用斜拉扣索吊装法施工,确保桥梁施工期间正常通航。采用空间有限元软件MIDAS Civil对该桥的静、动力性能进行分析,计算时考虑桩土相互作用,结果表明各项指标均满足规范要求。     

软土地基上承式景观拱桥设计

结合软土地基修建景观拱桥工程实例,探讨平衡拱桥水平推力的方法,对比有推力结构体系和无推力结构体系的受力情况及适用范围,并对桥台阻滑板和暗埋刚性系杆结构进行计算分析,可为类似项目的设计提供借鉴.     

The nonconventional thin-walled arch rib design and its numerical verification of a long span steel arch bridge

Arch bridges have been widely constructed in China owing to their versatile structural configurations and competitive costs. The concept of using high performance prestressed steel wires to withstand the huge horizontal thrust at arch ends has greatly encouraged the engineering practices of large span arch type bridges constructed on soft soil foundations where normally arch structure is an inappropriate selection. However, many technical challenges including the design details, structural behavior and construction method still need to be carefully investigated to ensure the bridge′s safety. As a new practice of such tied arch bridge with nonconventional thin-walled steel box rib and the longest span of this type in the world, this paper presents the innovative design concept and the corresponding studies in regard to its structural behavior compared with conventional single arch design, the shear lag effect of the thin-walled arch rib and its stress distribution via numerical analysis of different finite element models are also investigated. The results show that the current design can reach a very good structural behavior under design load cases, and moreover, provides another very useful engineering practice for long span arch bridge constructed on soft soil foundations.     

软土地基上拱桥的设计初探

拱作为一种传统的结构型式,始终是桥梁的主要比选方案之一.在软土地基上建造拱桥首先要解决拱脚处的水平推力以及软土地基的流变问题.通过昆山正阳桥的设计,从结构体系和下部结构基础形式的比选,对软土地基上拱桥的设计作了初步的探索,以期为今后相关的工程提供参考.     

Bewertung bestehender Natursteinbogenbrücken

Assessment of existing natural stone arch bridges. Arch bridges made of natural stone masonry rank among the oldest structures still in full function within road and railways. With a age from partly far over 100 years these represent historically very valuable built volumes in large number of several thousand buildings at the same time. The oldest existing bridges based on empirical values design, later there were graphic procedures for structural design, one developed approximation formulas on basis of the arch line of thrust for the draft of substantial geometry parameters such as span, type of arch as well as arch thickness at the crown and springing. In the course of the revision of these buildings evaluations regarding load‐carrying capacity and serviceability on the basis are demanded under today valid loads and standards. In this paper apart from a short overview to the existing arch bridges the possibilities of the structural modelling are discussed. An emphasis forms the computation of the masonry load‐carrying capacity, which is described in particular by safety considerations. The procedures referred to the bridge construction are transferable in principle to other structures of building construction.     

宁波姚江大桥抗震性能研究

目前,大跨度钢桁架拱桥的抗震设计分析相对较少,无规范可遵循.以宁波城庄路姚江大桥为例,建立了主桥和引桥一体的动力分析模型,分析了桥跨结构的动力特性和地震反应,探讨了主、引桥相互间的影响作用,并比较了几种改善抗震性能措施的效果.罕遇地震下主桥纵向固定墩基础难满足抗震要求,可采用减震措施.     

Die Bogenbrücken der A 17 – Entwurf und Ausführung

The Arch Bridges of the A 17, design and erection – three examples of arch bridges with piered bridge deck. In the course of the newly built highway A 17 were built three concrete arch bridges with piered bridge deck. The characteristics of the bridges and the type of construction are reported on. The bridge across the Seidewitz Valley has an overall length of 568 m and a span of the arch of 154 m. The bridge is the classic case of an arch bridge built using the suspended cantilever method. The Bridge Wölkau has a total length of 57 m and an arch span of 47 m. The bridge is an example for the crossing of a highway with special regard to aesthetics. The bridge across the Lockwitz Valley has an overall length of 723 m and crosses a long valley in a max. heigth of 64 m. The two main spans are each 125 m. In four of the spans are situated arches, which together with the composite superstructure and the piers form an integral frame system. The construction shows a new way for deploying the aesthetic value of arch systems in the crossing of valleys up to now thought as not suitable for this.     

大跨度简支系杆拱桥抗震设计

系杆拱桥在跨航道领域应用广泛,抗震设计通常控制下部结构。以1座150 m下承式简支系杆拱桥为例,就抗震设计的几个关键性问题进行梳理和分析,包括抗震性能目标的确定、抗震体系的选择、剪断力的选取、减震位移的控制及抗震措施的设计。最后对未涉及问题进行补充。这些可供大跨度拱桥抗震设计时参考。     

#br# 我国钢管混凝土拱桥应用现状与展望

共收集到截止2015年1月的已建和在建的钢管混凝土拱桥413座（跨径不小于50m）。统计分析表明,钢管混凝土拱桥在我国修建的数量不断增多、跨径不断增大。从行业分布来看,在公路、城市桥梁中的应用仍是主体,在铁路尤其是高速铁路中的应用不断增多。在结构体系方面,上承式、中承式、拱梁组合式、飞鸟式和下承式刚架系杆拱5大类,仍为主要应用的桥型,占总数的85%。在截面形式方面,以圆钢管混凝土为基本单元组成的单圆管、哑铃形和桁式是应用的主流。提篮拱被应用于各种桥型,尤其是大跨度铁路桥。无风撑拱主要应用于120m跨径以下的桥梁,且以斜靠拱和拱梁组合桥为主,截面多采用横向刚度较大的形式。拱肋的材料强度不断地提高,钢管以Q345钢为主,混凝土以C40、C50为主。虽然对桥面系强健性的重视在不断提高,然而强健性好的整体式和具有加劲纵梁的悬吊桥面系的应用还不够普及。钢管拱的架设方法仍以支架法、悬臂法和转体法3种为主,其中悬臂拼装法应用最多,适用跨径最大范围也最广。     

钢管混凝土在桥梁工程中的应用

钢管混凝土是一种轻质、高强的组合材料。近年来在桥梁工程中的应用已越来越多,是一种有效而经济的结构形式。钢管混凝土不仅已广泛用于拱式桥梁,在其他桥梁及桥梁的其他部位都已有应用。文章着重介绍了钢管混凝土在桥墩、连续刚构桥、斜拉桥和拱桥上的应用实例,并建议尽快完善桥梁设计规范中的相关内容,以促进钢管混凝土在桥梁工程中的应用与发展。     

石拱桥的加固与施工

介绍了一座3-11.6 m石拱桥的加固设计与施工技术,具体分析了设计施工要点、施工程序及应注意的关键点,从而为同类桥梁的加固积累经验,同时保证石拱桥的运营安全。