共查询到16条相似文献，搜索用时 156 毫秒
1.
朱朴 《黎明职业大学学报》2012,(4)
以ABAQUS有限元为工具,对钢腹杆-混凝土组合拱的受力性能进行分析,探讨不同钢腹杆壁厚、钢腹杆倾角及布置形式对受力性能的影响.结果表明,钢腹杆壁厚并非越大越好,它存在一个合理的取值范围.钢腹杆倾角越大,其极限承载力越小.不同钢腹杆布置形式会影响钢腹杆-混凝土组合拱的竖向刚度,采用双N形布置形式下的钢腹杆-混凝土组合拱的竖向刚度较大. 相似文献
2.
董海军 《淮北职业技术学院学报》2013,12(1):105-107
采用有限元通用软件ANSYS对中承式钢管混凝土拱桥建立了空间分析模型,进行了自振特性分析,并对其模态特征进行了描述。之后针对拱肋含钢率、横撑、桥面宽跨比以及矢跨比四个主要结构参数进行了分析,并通过改变这些主要参数,研究了其对大跨度双飞燕钢管混凝土拱桥动力特性的影响程度,并总结了该类结构的动力特点。 相似文献
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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. 相似文献
4.
大跨度钢管混凝土拱桥设计与施工综述 总被引：1，自引：0，他引：1
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。 相似文献
5.
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. 相似文献
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刘洁 《杨凌职业技术学院学报》2015,(1):1-5
基于对加纵肋薄壁方钢管混凝土短柱在轴压荷载下局部屈曲性能的理论分析,利用能量法,推导了当加劲肋与壁板发生整体屈曲时,设置多条纵向加劲肋数量时加肋壁板的屈曲应力计算公式,在此基础上对比分析了影响单肋、双肋、三肋方钢管混凝土短柱临界屈曲系数大小,结果表明,增加加劲肋数量对提高壁板局部屈曲系数作用并不显著,在加劲肋总截面面积不变的情况下,加劲肋数量增加甚至会使壁板局部屈曲系数有所降低,增加加劲肋刚度对改善壁板局部稳定最为有效。本文结论可为带肋方钢管混凝土设计提供参考。 相似文献
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通过理论研究和数值计算，详细分析了大跨径钢管混凝土双肋拱桥的侧倾稳定性和地震响应。首先，根据双肋拱桥结构在竖向均布荷栽作用下的侧倾稳定临界力的近似解析解，讨论了横撑设置、横撑刚度等因素对稳定性的影响。其次，基于多点激振理论和拟静力位移概念，介绍了拱桥结构的动力特点和地震动作用下的响应，并讨论了行波效应的影响。分析表明，地震行波作用对大跨度拱桥影响很大，横撑设置对稳定性敏感。 相似文献
9.
欧智菁俞杰林上顺王金泽 《福建工程学院学报》2019,(6):511-517
以黄桷湾特大桥为工程背景,选取轴压比、梁墩刚度比、系梁布置形式及柱肢混凝土强度等级为设计参数,应用Midas Civil有限元软件构造了20座三跨对称桥梁计算模型。研究E1地震作用下钢管混凝土双肢格构墩连续梁桥主要控制截面参数地震响应,探讨各设计参数对钢管混凝土双肢格构墩连续梁桥抗震性能的影响规律,并对全桥进行优化验证。研究结果表明:轴压比对地震作用下结构内力和位移有一定影响,建议控制在0.15~0.25;梁墩刚度比对结构的抗震性能影响较大,控制在4.08~10.90时结构的内力分布更加合理;核心混凝土的强度在C40~C50时取值较为合理。 相似文献
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本文采用非线性有限元方法对哑铃型钢管混凝土拱桥进行面内弹塑性分析．以解放大桥的中孔拱桥为研究对象,分别考虑了施工阶段和成桥阶段的受力情况,计算了该桥在施工和成桥阶段的弹塑性稳定安全系数,并讨论了不同程度的初始挠度对弹塑性稳定安全系数的影响。分析结果可供哑铃型截面钢管混凝土拱桥的设计建设参考。 相似文献
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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. 相似文献
12.
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% 相似文献
13.
Approach for analyzing the ultimate strength of concrete filled steel tubular arch bridges with stiffening girder 总被引：2，自引：0，他引：2
ZHANG Zhi-cheng XIE Xu ZHANG He CHEN Heng-zhi 《浙江大学学报(A卷英文版)》2007,8(5):682-692
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. 相似文献
14.
评价既有桥梁可靠性的FNM法(英文) 总被引：1，自引：0，他引：1
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. 相似文献
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傅鹏斌 《河北职业技术学院学报》2010,(1)
论述了目前钢管混凝土柱节点的常见型式,分析了加强环式节点、穿心牛腿环梁节点、钢筋贯通式刚接节点、锚定式节点、十字板式节点、分层式节点和环梁式节点的构造特点和各自的优缺点。指出钢管混凝土柱节点在理论研究和实际应用中的一些问题。 相似文献
16.
The stability and ductility of four buckling-restrained braces （BRBs） with brace joints were studied. The load-carrying element of BRB was fabricated with steel （Chinese Q235）, and a layer of colloidal silica sheet （0.5 mm in thickness） or four layers of plastic film （0.2 mm in thickness） were used as unbonding materials to provide space to prevent the buckling of inner core in higher modes and facilitate its lateral expansion in case of compression. Based on the equation of BRBs with brace joints of different restrained stiffnesses, the buckling load is calculated considering the initial geometric imperfections and residual stress, and the theoretical values agree well with the experiment re- sults. It is concluded that the buckling load and ductility of BRBs are influenced greatly by the restrained stiffness of brace joints. If the restrained stiffness is deficient, the unstrained segment of BRBs with less stiffness will buckle firstly. As a result, the ultimate load of BRBs decreases, and the maximum compression load is reduced to about 65% of the maximum tension load; the stiffness also degenerates, and there is a long decreasing stage on the back-bone curve in compression phase; the ductility decreases, i.e., the ultimate tension ductility and ultimate compression ductil- ity are approximately 15 and 1.3 respectively, and the cumulative plastic ductility is only approximately 200. If the restrained stiffness of joint is large enough, the stability will be improved as follows： the yielding strength and ultimate strength of BRBs are nearly the same, and there is an obvious strain intensification in both tension and compression phases; the ductility of brace also increases obviously, i.e., the ultimate tension ductility and ultimate compression ductility are both approximately 14, and the cumulative plastic ductility reaches 782. 相似文献