Ultimate strength and ductility of stiffened steel tubular bridge piers

This paper presents the ultimate strength and ductility of steel tubular bridge piers with the inner cruciform plates, the stiffener plates, the concrete-filled sections and the outer tube subjected to monotonic and cyclic horizontal loads. Numerical analyses were carried out using the finite element package MARC. Firstly, to check the validity of the numerical analysis, the analytical results of the steel tubular columns with the inner cruciform plates, the concrete filled sections and the outer tube were compared with the previous experimental results. Secondly, the effects of the radius-to-thickness ratio parameter and the slenderness ratio parameter on seismic performance (the ductility, the ultimate strength etc.) of these steel tubular piers were examined. Numerical results indicated that the steel column with inner cruciform plates was able to improve the ultimate strength and ductility of the steel tubular piers.     

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.     

钢箱梁与钢桁架人行天桥力学性能对比分析

为了分析并对比钢箱梁与钢桁架人行天桥的力学性能,建立了两者的ANSYS有限元计算模型,通过静力分析,得出钢桁架人行天桥的承载力更大,通过动力特性分析,钢桁架人行天桥较钢箱梁人行天桥更易产生扭转,且钢箱梁的自振频率较钢桁架的自振频率要大。     

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。     

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。     

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.     

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。     

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。     

Study on steel box girder bridges partly stiffened by CFT arch ribs

A new type of arch girder bridge, steel box girders partly stiffened by arch ribs, is proposed and the structural characteristic is studied. Arch ribs are concrete filled steel tubes (CFT) which have high resistance against compression and bending. A parametric study is carried out for the arch girder bridge with different ratios of arch span length to arch rise. Bending moment and tensile forces of the girder are largest with the shortest arch span and decrease as the arch span becomes longer. On the other hand bending moments of the girder do not significantly depend on the arch rise. Bending moments and compressive forces of the arch rib have the same tendency as the girder. Safety of the structural members is verified by the limit state design method considering non-linear stress versus strain relations of steel and concrete. Large deformation elastic–plastic analysis is conducted for the basic case of the proposed bridge to clarify the global buckling strength. Three inclined angles of the arch rib plane are assumed as initial imperfections. The larger initial imperfection decreases the lateral torsional buckling strength. Estimated construction cost of the arch girder bridge with steel pipes without concrete filling is 9% higher than that of the basic CFT arch girder case. The pure CFT arch bridge is the most economical and 23% lower than the basic case. However, as the arch rise of this pure arch bridge is higher, its esthetics may be inferior and it also restricts the available aerial space. This study shows that the proposed bridge has sufficient resistance against bending, compression, global buckling and is considered feasible.     

螺纹钢法兰连接预制装配桥墩抗震性能研究

为研究在水平荷载作用下螺纹钢法兰连接预制装配桥墩的抗震性能,设计制作一个整体现浇桥墩、两个分别采用承插式和非承插式方案的螺纹钢法兰连接预制桥墩.通过开展拟静力加载试验,对比研究螺纹钢法兰连接预制装配桥墩与整体现浇桥墩的破坏模式、荷载-位移曲线特征.基于试验,建立三个桥墩的有限元数值模型与试验进行对比,两者结果吻合较好....     

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。     

FEA on hysteretic behavior of concrete-filled round-ended stainless steel tubular bridge piers

为研究圆端形不锈钢管混凝土桥墩的滞回性能,采用有限元分析软件ABAQUS,建立了圆端形不锈钢管混凝土桥墩的精细化模型,对比研究其与圆端形普通钢管混凝土桥墩受力性能的差异,并对影响其滞回性能的主要因素进行参数分析。研究发现：采用不锈钢与普通钢的圆端形钢管混凝土桥墩承载力相当,但由于不锈钢存在较为显著的应变强化现象,前者的荷载-位移曲线下降更为平缓,圆端形不锈钢管在加载后期仍能对核心混凝土提供较好的约束作用;随截面长宽比增加,圆端形不锈钢管混凝土桥墩的水平承载力明显增加,但位移延性明显下降;随含钢率增加,桥墩的抗侧刚度、水平承载力、位移延性均明显增加;随轴压比增加,桥墩水平承载力略有降低,而位移延性明显下降;而核心混凝土强度对桥墩的滞回性能影响有限。     

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。     

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。     

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.     

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。     

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。     

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.