无风撑背靠式钢管混凝土拱桥施工技术探究

结合韩江北桥的设计和施工,对无风撑背靠式钢管混凝土拱桥进行了简单阐述,分析了无风撑拱桥的施工控制、设计方法等重要内容,这对拱桥的有效建设具有借鉴意义,同时对钢管拱桥设计和施工的完善具有重要作用。     

倮裹钢管混凝土拱桥施工控制

结合钢管混凝土拱桥施工控制的实例,探讨钢管混凝土拱桥施工控制的主要内容与控制方法,对监控结果进行分析,并对施工中需注意的事项提出几点建议。     

倮裹钢管混凝土拱桥施工控制

结合钢管混凝土拱桥施工控制的实例，探讨钢管混凝土拱桥施工控制的主要内容与控制方法，对监控结果进行分析，并对施工中需注意的事项提出几点建议。     

钢管混凝土拱桥下部施工技术探究

钢管混凝土拱桥在当今桥梁建设中发挥着重要的作用,从钢管混凝土拱桥结构特点入手,分析拱桥下部结构施工技术对当今路桥事业的发展有重要作用.     

钢管混凝土拱桥施工工艺

某大桥为连续五孔无风撑、双承载面下承式的钢管混凝土系杆拱桥,以本桥为例,介绍钢管混凝土拱桥的施工工艺及要点。     

钢管混凝土拱桥基于有限元的整体稳定性分析

从工程实例出发,对一座钢管混凝土拱桥建立了有限元模型,从线弹性和几何非线性两个方面进行了数值分析,分析表明该桥的屈曲稳定比较可靠,结构失稳模态均为拱肋面外失稳,表明拱肋的横向刚度相对系梁较弱.     

大跨度钢管混凝土拱桥设计与施工综述

从设计、施工以及养护诸方面探讨了大跨径钢管混凝土拱桥建设中需注意的问题。设计方面包括拱轴线的选择、拱脚段负弯矩的处理、横撑设置与稳定性、桥道系的选择等；施工养护方面包括钢管焊接、缆索吊装与斜拉扣挂、泵送混凝土与灌注次序、施工控制与检测、防腐与换索等。     

浅谈钢管混凝土拱桥侧倾稳定性影响的因素

首先介绍了钢管混凝土拱桥稳定性分析中常用的基本理论,然后根据所收集到的有关钢管混凝土拱桥侧倾稳定性的资料,介绍了其中比较重要的影响因素.其中包括横撑,拱肋,边界处理等对钢管混凝土拱桥稳定性的影响.     

钢管混凝土拱桥静载试验方法研究

钢管混凝土拱桥以其跨度适应能力大、模块化施工、承载能力强、外形美观等优点,近年来受到桥梁建设者的亲睐。依托某钢管混凝土拱桥实际工程,系统地阐述了钢管拱桥静载试验控制断面的选择、测试内容、建模分析,在各项先进检测手段的基础上,从结构强度、刚度及弹性工作性能评价了桥梁工作状况,可为同类工程提供借鉴与参考。     

大跨度钢管砼拱桥地震反应分析近期研究进展

综述了近期大跨度钢管混凝土拱桥地震反应分析的研究进展.对大跨度钢管混凝土拱桥拱肋的模拟方法、地震反应分析方法和地震反应特征进行了简述,并提出了进一步研究的若干建议.     

Approach for analyzing the ultimate strength of concrete filled steel tubular arch bridges with stiffening girder

A convenient approach is proposed for analyzing the ultimate load carrying capacity of concrete filled steel tubular (CFST) arch bridge with stiffening girders. A fiber model beam element is specially used to simulate the stiffening girder and CFST arch rib. The geometric nonlinearity, material nonlinearity, influence of the construction process and the contribution of prestressing reinforcement are all taken into consideration. The accuracy of this method is validated by comparing its results with experimental results. Finally, the ultimate strength of an abnormal CFST arch bridge with stiffening girders is investigated and the effect of construction method is discussed. It is concluded that the construction process has little effect on the ultimate strength of the bridge.     

钢管混凝土组拼管拱面外屈曲参数分析

以福鼎山前大桥空间有限元模型为基础,分析了影响钢管混凝土组拼管拱面外屈曲的主要参数,包括横撑布置形式、横撑刚度、拱脚约束情况、截面含钢率和混凝土弹性模量.有限元分析结果表明,横撑布置形式、横撑刚度和截面含钢率对钢管混凝土组拼管拱面外屈曲影响很大,但混凝土强度等级和拱脚约束对其影响很小.     

Numerical analysis of ultimate strength of concrete filled steel tubular arch bridges

INTRODUCTION As a result of the combined effects of the rolled steel tube and the core concrete, Concrete Filled Steel Tubular (CFST) structures can effectively take ad-vantage of these two materials to improve the com-pressive strength and the ductility of the structures. This kind of structure is developing quickly in China and widely used in high-rise structures and bridges. Recently, due to the development of construction projects, numerous studies on CFST structures have been i…     

钢管混凝土系杆拱桥拱肋的架设

对钢管混凝土系杆拱桥拱肋的两种架设方式进行了探讨，即竖向转体施工架设法和缆索、扣索分段吊装架设法，并对缆索、扣索吊装施工中的实施要点与措施进行了分析，同时讨论了两种架设方法的优缺点及适用范围．     

In-plane creep buckling of concrete-filled steel tubular arches

The creep-induced deformation of the arch rib of concrete-filled steel tubular （CFST） arches under a sustained load can increase the bending moment, which may lead to earlier stability failure called creep buckling. To investigate the influences of concrete creep on the buckling strength of arches, a theoretical analysis for the creep buckling of CFST circular arches under distributed radial load is performed. The simplified Arutyunyan-Maslov （AM） creep law is used to model the creep behavior of concrete core, and the creep integral operator is introduced. The analytical solutions of the time-dependent buckling strength under the sustained load are achieved and compared with the existing formula based on the age-adjusted effective modulus method （AEMM）. Then the solutions are used to determine the influences of the steel ratio and the first loading age on the creep buckling of CFST arches. The results show that the analytical solutions are of good accuracy and applicability. For CFST arches, the steel ratio and the first loading age have significant influences on creep buckling. An approximate log-linear relationship between the decreased degrees of the creep buckling strength and the first loading age is found. For the commonly used parameters, the maximum loss of the buckling strength induced bv concrete creen is close to 40%     

评价既有桥梁可靠性的FNM法(英文)

结合现行规范及钢管混凝土拱桥的受力特点,给出钢管混凝土拱桥安全-中介-失效三级工作模式的确定准则.据此计算结构的损伤概率与失效概率及对应的可靠度指标,建立可靠度指标与三级工作模式的直接关系.基于三级工作模式,提出评估在役桥梁结构可靠度的有限元-神经网络-蒙特卡罗(FNM)法.根据时变可靠度理论,将结构继续服役期离散化,随机抽样生成蒙特卡罗法所需的最少样本,由随机有限元法计算训练样本,用神经网络扩展训练样本,最后通过蒙特卡罗法计算失效概率和损伤概率,得到结构时变可靠度,判断其工作状态.运用该方法对一座建成10年,主跨83.6 m的钢管混凝土拱桥进行分析,结果表明,该桥主拱处于安全状态,这一结论与实际情况相符.说明FNM法对于评价在役桥梁的可靠性是可行的.     

Optimum design of large span concrete filled steel tubular arch bridge based on static,stability and modal analysis

A three-dimensional finite element model was established for a large span concrete filled steel tubular (CFST) arch bridge which is currently under construction. The arch rib, the spandrel columns, the prestressed concrete box-beam, the cast-in-situ concrete plate of bridge deck, the steel box-beam and the crossbeams connecting the two pieces of arch ribs, were modeled by three-dimensional Timoshenko beam elements (3DTBE). The suspenders were modeled by three-dimensional cable elements (3DCE). Both geometric nonlinearity and prestress effect could be included in each kind of element. At the same time a second finite element model with the same geometric and material properties excepted for the sectional dimension of arch rib was set up. Static dynamic analyses were performed to determine the corresponding characteristics of the structure. The results showed that the arch rib's axial rigidity could be determined by static analysis. The stability and vibration of this system could be separated into in-plane modes, out-of-plane modes and coupled modes. The in-plane stability and dynamic characteristics are determined by the arch rib's vertical stiffness and that of out-of-plane is determined by the crossbeams' stiffness and arch rib's lateral stiffness mainly. The in-plane stiffness is much greater than that of out-of-plane for this kind of bridge . The effect of geometric nonlinearity and prestress effect on bridge behavior is insignificant.     

“霞溪本”橄榄小苗嫁接试验研究

以二年生橄榄实生容器苗(以薄膜袋育苗)为砧木,取霞溪本橄榄充实健壮的秋梢为接进行小苗嫁接试验,研究环境因素、嫁接时间、接选择与处理、砧木处理等对橄榄嫁接成活率的影响。试验结果表明:3月10日前后采用砧木留叶、二年生充实健壮的秋梢作接,并以100mg/L的NAA处理,在覆盖透光率50%遮阳网的小拱棚里进行嫁接。嫁接后40天内保持棚内温度20—25℃、相对湿度80—88%,之后拆除小拱棚,嫁接成活率和成苗率高且稳定,其分别可达90.5%和78%,橄榄实生容器苗于小塑料拱棚可控环境条件下进行嫁接是橄榄苗木生产上提高嫁接成活率及其稳定性的重要措施。     

钢管混凝土在侧向冲击作用下的耐撞性研究

钢管混凝土结构构件充分发挥了钢管与混凝土两种材料的特性和潜力,近年来越来越广泛地被用于工业与民用建筑、大型桥梁及地下结构等重要工程领域。借助DHR9401型落锤式冲击实验机,完成了两端固定边界条件下,两种壁厚的钢管混凝土梁的侧向撞击试验,得出以下结论：钢管混凝土构件具有良好的抗冲击作用,在构件受到突加荷载作用时,表现出了很好的延性;钢管混凝土受到侧向冲击时,材料有明显的屈服阶段;落锤的速度越高和质量越大,构件的动力响应越明显。     

钢管混凝土系杆拱桥空间效应分析

建立平面与空间有限元模型，对郑州黄河公路钢管混凝土系杆拱桥(二桥)的活载横向分布系数、横粱、拱肋和系梁的受力特点进行比较分析，重点考察结构的空间效应问题，并分析了结构第一类空间稳定系数及其主要影响因素。分析结果表明，活载横向分布系数采用杠杆法与空间分析结果相近，可用于设计计算之中；系梁承受有较大的扭矩；吊杆横梁的受力性质接近于简支梁，而端横梁的受力要进行空间分析，考虑系梁扭矩的作用；K撑中的斜撑和系梁安装支架对提高结构稳定系数贡献较大。