Seismic performance of new-type box steel bridge piers with embedded energy-dissipating shell plates under tri-directional seismic coupling action

Accurate numerical models are necessary to evaluate the seismic performance and load-bearing mechanism of new-type box steel bridge piers with embedded energy-dissipating shell plates under tri-directional seismic coupling action. Numerical simulations of seismic performance under six types of tri-directional seismic coupling action was conducted. The effects of this stress on the seismic performance of the new-type steel bridge piers was evaluated through analysis of damage mode, hysteresis curve, skeleton curve, stiffness and strength degradation characteristic, and energy-dissipating capacity. This study also compared the numerical analysis with experimental results in order to validate the accuracy of the proposed finite element model. Based on this model, the range of relevant parameters expanded and 88 numerical specimens were analysed for seismic performance, producing further information about the influence of thickness and curvature of the embedded shell plate, spacing of transverse stiffening ribs of the shell, axial compression ratio, and slenderness ratio. Results showed that tri-directional seismic coupling action significantly affects the specimen’s deformation capacity; the embedded shell plate effectively improves the piers’ load-carrying and deformation capacity; and the thickness of the embedded shell plate, width-to-thickness ratio of the wall plate, axial compression ratio, and slenderness ratio significantly affect the seismic performance of the new-type steel bridge piers. To promote the ease of seismic design of new-type box steel bridge piers, this study used theoretical analysis and numerical simulation to calculate equations for the minimum height of the energy-dissipating zone of the bottom embedded shell plate. Finally, formulas were also established to calculate the relevant stability bearing capacity and displacement ductility factor of the new-type steel bridge piers under tri-directional seismic coupling action in order to improve their seismic design.     

独柱墩连续箱梁弯桥抗倾覆验算

我国制定的新规范《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTGD62—2012）中给出了独柱墩箱梁抗倾覆验算的明确规定。该文运用新规范．采用MADIS／Civil软件,对正在运营的3跨连续箱梁弯桥进行抗倾覆验算。为今后此类桥梁的抗倾覆验算提供一定的参考。     

Numerical and experimental investigations on the compression behaviour of stiffened plates

The main objective of this paper is to present the results of the finite element method for non-linear analysis of stiffened plates subjected to axial compression load considering post-buckling behaviour up to collapse. For this purpose two series of well executed experimental data on longitudinally stiffened steel plates with and without transversal stiffeners subjected to uniform axial in-plane load carried out to study the buckling and post-buckling up to final failure have been chosen. The first series are those of Ghavami where the influences of stiffener cross-section of the type rectangular (R), L and T, their spacing and the presence of rigid transversal stiffeners have been studied. The second series of Tanaka & Endo, where the behaviour of stiffened plates having three and two flat bars for longitudinal and transversal stiffeners respectively were analysed. For the purpose a well-established commercially available Finite Element program ANSYS has been chosen. The selected element was SHELL43, which can trace the full-range, elastic-plastic behaviour of the stiffened plates. It is seen that the simulated results of FEM are in good consistency with the test results.     

双箱单室钢箱梁桥设计

钢桥是大跨度桥梁的主要形式。以山东XX双箱单室钢桥为例,详细介绍钢桥总体优化设计,通过桥梁博士建立有限元模型,计算结果表明拉/压弯构件弯曲正应力验算、剪应力验算、折算应力验算、挠度验算、疲劳验算均满足要求。     

内填部分混凝土箱形截面钢桥墩的滞回性能研究

首先,利用试验方法对内填部分混凝土箱形截面钢桥墩在承受水平反复荷载作用下的滞回性能进行研究,探讨翼缘宽厚比参数和混凝土填充率对钢桥墩滞回性能的影响。然后,采用弹塑性有限元分析方法,对试验结果进行数值模拟。研究结果表明,钢桥墩的延性随着翼缘宽厚比的减小和混凝土填充率的提高而得到显著提高。由数值模拟得到的试件的滞回曲线、钢板局部屈曲模态等,与试验结果吻合较好。     

独柱墩连续箱梁弯桥抗倾覆验算

我国制定的新规范《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTGD62—2012）中给出了独柱墩箱梁抗倾覆验算的明确规定。该文运用新规范。采用MADIS／Civil软件,对正在运营的3跨连续箱梁弯桥进行抗倾覆验算。为今后此类桥梁的抗倾覆验算提供一定的参考。     

桥跨比对波纹钢腹板组合箱梁桥动力特性的影响

采用Midas建立某波纹钢腹板三跨连续梁桥有限元模型,分析不同桥跨比对该新型结构的动力特性的影响,从分析结果中提取振型模态及振动频率并进行数据对比,提出了合理的桥跨比范围,为实际设计波纹钢腹板箱梁桥提供参考。     

辅助墩对大跨度高低墩斜拉桥抗震性能的影响

以某大跨度高低墩斜拉桥为研究对象,采用控制变量法,分析了辅助墩对结构抗震性能的影响,结果表明:增设适当数量的辅助墩可以有效减小地震作用下结构关键部位的内力及变形。     

连续钢箱梁桥轻型超高性能铺装施工技术

为解决贵安新区歆民路车田河大桥桥面铺装结构性能可靠性问题,提高铺装结构使用寿命,降低后期运维工作量及成本,采用了STC+TPO(超高韧性混凝土)铺装技术。桥面铺装结构为50 mm STC(超高韧性混凝土)+20 mm TPO(薄层聚合物混凝土磨耗层),通过对钢桥面板喷砂除锈,达到SA2.5级清洁度,按照比例将mark-163聚氨酯环氧树脂涂刷于STC层与TPO层之间,共同形成了超高性能轻型桥面铺装体系。其中STC层施工采用了专用特殊机械进行布料、振捣及养护施工,确保了桥面铺装结构的可靠性,桥面铺装效果良好。该项目的施工技术及质量控制标准可为类似工程提供有益参考。     

钢箱拱桥试验模型的设计

以罗浮山东江博罗大桥为实体桥,利用相似原理、方程分析法和量纲分析法,对该系杆拱桥进行相似分析,建立钢箱拱桥试验模型,再利用方程分析法,求弹性模量和密度需满足的条件,为碳纤维吊、系杆在拱桥中的推广应用提供了可靠的理论依据。     

钢箱梁吊装临时支墩现场设计与力学分析

为了确保郑东新区龙湖区龙行桥工程钢箱梁吊装临时支墩的稳定,采用MIDAS专业软件,从理论的角度对临时支墩结构进行了全方位的理论分析,验证了各个施工工况下的临时支墩结构强度、入土深度指标的可行性,为施工提供了理论依据。     

大曲率小半径连续弯钢箱梁桥受力性能分析

采用空间有限元方法,对大曲率小半径钢箱梁进行了研究分析,对结构在不同荷载效应下的响应作了分析和横向比较,并对曲线钢箱梁桥的受力特点、剪力滞效应和实用计算方法进行了探讨,结果表明,增设横隔板是减小薄腹箱梁截面畸变变形的最优方案.     

Strength and ductility evaluation of steel bridge piers with linearly tapered plates

Important issues on the application of linearly tapered steel plates to highway bridge piers are discussed in this paper based on extensive experimental work. The factors that affect the seismic resisting performance of tapered plate steel columns were examined. The main factors considered are: (1) types of tapering mold line (outer, central, and inside tapering); (2) tapering ratio (or the slope of thickness change); (3) stiffeners’ rigidity; and (4) tapered stiffeners. To this end, four groups of specimens were tested under cyclic lateral loads and constant axial load. The columns with the outside taper plates were found to have the best strength and ductility characteristics among the three types of mold lines. In the case of different tapering ratios, the largest ductility was observed in the specimens with the tapering ratio slightly less than or equal to unity. The stiffeners’ rigidity ratio of around 3.0 was found to give the best ductility performance in columns with both constant thickness and varying thickness stiffeners. The test results were compared with a recently proposed design equation for limit strain of box columns with tapered plates. Finally, finite element analyses were performed and comparisons between the test and the analyses’ results of several test specimens are presented.     

箱肋拱桥施工技术

结合工程实例,介绍了箱肋拱桥施工技术,从箱肋拱桥的特点、拱肋的施工、拱肋的吊装等方面进行了论述,指出箱肋拱桥的施工技术,具有结构简单、自重轻、跨度大、造价低、施工方便、工期短、质量保证、外型美观等特点,值得推广应用。     

人行天桥动力性能研究

结合福州某环形天桥管养工作,对该人行天桥的动力性能和人致振动的舒适性开展探讨,通过动力测试及有限元模型分析,结果表明竖向基频低于3Hz,引起行人不适,建议通过增强天桥主梁刚度或设置减震措施,同时避免在天桥上设置广告而增加自重。     

Influence of bridge deck on tsunami loading on inland bridge piers

The customary method of computing the hydrodynamic force on a pier of a bridge is based on the model tests of stand-alone piers. This implicitly ignores the influence of the deck on the flow pattern around the piers. The hydrodynamic force exerted on the piers by a solitary-like wave generated in a hydraulic wave flume is investigated using a complete pier-deck model, which includes both the pier and deck in the actual proportion. The experimental results reveal that the hydrodynamic force on the piers is influenced by the presence of the deck. For the complete bridge configuration studied, the actual force component which results from the hydrodynamic pressure acting on the piers only could be increased by as much as 50% over that for the case of stand-alone piers. This is due to the influence of the deck in obstructing the free splashing and topping over of the wave upon striking the piers, resulting in accumulation of fluid in front of the piers, and hence increasing the pressure on them. Thus, the hydrodynamic force computed based on experiments on stand-alone piers could be non-conservative for design of piers.     

大跨度V形拱钢拱桥稳定性分析

V形拱桥造型美观,结构体系新颖,随着其跨度增大,拱肋建筑高度增高,稳定问题突出,对其稳定性进行分析具有重要意义。以现有理论为基础,主跨115 m的V形拱桥为背景,采用Midas civil有限元软件建立模型,对该桥成桥状态的结构稳定性进行了分析。结果表明,该桥的整体失稳主要表现为拱肋面外失稳;拉索位于拱肋上的着力点和横撑加装位置宜设置在拱顶靠近两拱肋相交侧。     

基于动态可靠度的桥梁性能分析

在研究了现有混凝土桥梁抗力和荷载时变性的基础上,建立了桥梁动态可靠性的随机过程模型,并利用蒙特卡罗方法计算寿命周期内的动态可靠指标,同时,利用此模型对一座基于全寿命设计理念的试验桥进行时变性能对比分析与寿命预测,对合理、经济、科学的制定维护时间与维护方案具有重要的指导意义。     

变截面钢箱梁人行天桥的有限元分析

应用大型通用有限元分析软件ABAQUS,采用壳单元对某变截面钢箱梁人行天桥进行了详细的模拟分析,准确地验算了主梁的强度、变形等,结果表明该分析方法效果较好,可为今后类似工程提供指导。     

辅助墩对预应力混凝土斜拉桥动力特性的影响

基于有限元方法,以南太湖大桥为例,考虑有无辅助墩两种不同的结构形式,通过建立空间动力计算模型对独塔双索面预应力混凝土协作体系斜拉桥进行动力特性计算与分析,以促进预应力混凝土斜拉桥动力特性的研究。