大型桥梁钢索塔制作关键技术探析

首先对国内外桥梁钢索塔建造现状及应用前景进行了介绍,然后对典型桥梁钢索塔的结构特点进行了分析。结合桥梁钢索塔结构特点,重点对制作方案策划、焊接变形及几何精度控制技术、曲线形钢索塔节段制作技术、钢索塔预拼装技术及自动化制作等方面进行了阐述,解决了钢索塔制作的难题,取得了良好的效果。     

沪杭高铁112m钢桁架桥梁的加工工艺研究

本文通过对沪杭高铁沿线112m钢桁架桥梁的构件制作的重点和难点的分析,阐述了深化设计过程、加工工艺要点、箱型弦杆制孔方案,并通过实践验证,钢桁架桥梁满足设计及规范的要求。     

港珠澳大桥组合梁钢主梁大节段制作关键技术研究

简要介绍了港珠澳大桥浅水区非通航孔桥组合梁的工程概况,分析了组合梁钢主梁大节段制作的难点,重点阐述了钢主梁大节段整孔制作方案、线形控制、梁段长度及端面夹角的控制措施,同时对钢主梁总拼自动化焊接技术进行了介绍。通过在工程实际中应用,解决了组合梁钢主梁制造线形及梁长控制等难题,取得了很好的效果。     

基于数值分析的桥梁顶升钢抱箍优化设计

为满足广东省某连续桥梁顶升更换支座工程的需要,设计钢结构抱箍装置作为顶升系统的反力支撑平台。根据顶升力的大小及现场顶升条件,提出钢抱箍的初步设计方案,采用ANSYS有限元软件进行仿真计算。结果表明,钢抱箍刚度及稳定性满足要求,强度不满足要求,存在应力集中现象。制作钢抱箍试件,进行现场加载试验,测试结果与有限元分析结果十分吻合,验证有限元分析方法的正确性。提出结构优化设计方案,进一步减少钢抱箍局部应力集中的优化构造措施。优化后的钢抱箍现场测试试验结果表明,在设计最大顶升力作用下,钢抱箍系统的强度、刚度、稳定性均满足要求,验证优化方案的有效性,成功实施桥梁顶升和支座更换工作。对钢抱箍的结构优化设计及提出的优化构造措施可为同类桥梁顶升工程钢抱箍系统的设计提供参考。     

预应力混凝土组合箱梁桥波纹钢腹板制作关键技术

简要介绍波纹钢腹板预应力混凝土(简称PC)组合结构桥梁的发展应用状况,针对波纹钢腹板的制作过程进行详细论述,分析波纹钢腹板制作过程的特点和难点。着重阐述波纹钢腹板压型模具设计、压型过程控制、节段组焊及桥位组装焊接的生产过程及质量控制措施,并对实际工程应用效果进行分析,解决了波纹钢腹板制作过程中冷弯成型等技术难题。     

箱型钢桥梁板单元自动化焊接技术应用研究

针对箱型钢桥梁板单元的自动化焊接技术,从方案选择到具体的试验验证,从焊接效率、焊接质量、成本等方面,对目前国际上两种先进而且主流的焊接方法进行对比试验分析,得出多头双丝焊接专机更适合肋板焊接的结论。但同时也对焊接机器人的优势及适用条件进行分析和表述。文章内容对桥梁钢结构制作中先进焊接技术的应用和推广具有借鉴和指导意义。     

箱形双螺旋钢桁架结构桥梁制作工艺

采用MIDAS整体计算和ANSYS Workbench节点应力分析对箱形双螺旋钢桁架桥梁进行优化设计,设计构件制作工艺流程,并详细描述了主要施工操作方法及步骤,该制作工艺具有一定的先进性和实用性。     

栖凤湖钢栈桥施工结构优化及工艺改进方式刍议

随着我国社会经济的不断发展,各种桥梁如雨后春笋般应运而生。钢栈桥作为水上桥梁的必备施工技术,具有交通运输和吊装平台等作用,方便装卸、经济适用,广泛的应用于各大城市的桥梁建设中。目前,我国钢栈桥施工技术得到了一定的改进,对钢栈桥搭设方案的设计也有了一定的要求,实现了较大利用空间的预留,确保施工过程中预算实际值的吻合,为我国交通桥梁建设的科学发展目标奠定了坚实的基础。本文就结合栖凤湖钢栈桥现场水中墩施工方案,对比以往常规的施工工艺,对施工结构的优化和工艺的改进进行讨论分析。     

粘钢法加固桥梁机理与应用浅议

本文简要分析了桥梁的加固的必要性,介绍了粘钢法的机理和施工工艺,分析了粘钢的抗弯、抗剪及锚固长度的计算理论,通过对某桥的梁板加固方案的比选,认为粘钢法经济合理。加固实践表明,粘钢法加固技术可行,施工方便,造价低,竣工动静载实验表明,加固能达到提高桥梁承载力的目的。可为同类桥梁加固提供参考。     

铁路工程中的门式墩钢盖梁吊装施工技术

以某铁路工程为实例,对其中的门式墩钢盖梁施工技术展开分析.由于该工程存在桥梁跨越既有铁路情况,为兼顾既有铁路正常运行以及新建部分质量要求,采用门式墩与钢盖梁相结合的方案,前者在现场现浇成型,后者提前在工厂制作,运至现场吊装到位.通过门式墩与钢盖梁的综合应用,可减小对既有线路的干扰,施工更安全高效.     

基于虚拟现实的钢结构桥梁装配化施工仿真系统

为提高钢结构桥梁装配质量,降低装配风险,使用SoidWorks和3ds Max软件建立钢结构桥梁施工场景模型,采用C#语言编写装配系统的核心脚本,提出并实现系统UI设计方案,结合Steam VR 2.0插件,以实际工程建设项目作为仿真分析对象,研究虚拟现实技术在钢结构桥梁装配过程中的应用。基于Unity3D虚拟引擎平台,设计并开发第一人称视角的沉浸式钢桥虚拟装配系统,采用HTC Vive外接式头戴设备对接系统调试运行,最终实现人机交互操作。结果表明:钢桥吊装施工过程中,汽车起重机吊臂最大工作长度为33.554 m,最大起升高度为12.365 m,主臂最大仰角为62.34°,各钢桥节段关键参数均未超过额定值,保证了施工质量和结构安全; 施工起重机在起吊阶段最大起升高度应高于6.7 m,防止构件与各钢桥节段碰撞干涉; 在此基础上,提高节段2的起升高度可排除桥梁节段间碰撞危险; 用户进行虚拟装配操作,验证了射线检测与UI交互功能的可行性; 现场应用表明所设计的系统稳定可靠,系统可预测施工过程风险并优化施工方案,提升了钢桥施工过程中智能化和自动化水平。     

对日本钢桥建造技术的几点思考

日本的钢桥建造技术堪称世界一流,设计上特别注重可靠性、合理性、经济性;在制造技术上大量采用机械化、自动化设备,提高了效率,并减小了人为因素对质量的影响,而且,特别注重精细化管理。多年来,在研究吸收日本等国外先进经验的基础上,我国在钢桥梁建设方面取得了可喜的成果,但仍有需要改进的地方,如:在钢桥设计方面存在一些误区,在钢桥制造、架设及精细化管理方面还有一定的差距。只有认识到不足并加以改进,才能全面提升我国钢桥梁的建造水平,可供建设方、设计、制造单位参考。     

钢—混凝土组合桥混凝土徐变收缩分析

本文介绍钢混凝土组合桥梁混凝土徐变、收缩分析的方法,研究内容涉及结合梁桥及钢管混凝土组合拱桥。文末给出了可供参考的结论     

大跨径钢桥桥面铺装材料研究现状

简要介绍了目前世界上主要的几种钢桥桥面铺装材料，并对各种材料的应用现状及前景作了简要分析，为钢桥面铺装材料设计提供一定参考。     

Development of improved natural frequency equations for continuous span steel I-girder bridges

Field testing and analytical studies to predict natural frequencies of steel stringer bridges are reviewed in this paper. A three-dimensional (3D) finite element analysis (FEA) procedure using the commercial software ABAQUS, which efficiently captures the vibration characteristics of such bridges, is proposed. Two continuous-span composite steel bridges dynamically (field) tested by others were used to validate the proposed FEA model, which indicates excellent agreement between the analytical and field data. A natural frequency parametric study has been conducted by utilizing the FEA procedure. Based on the regression analysis of the parametric study results, practical equations are proposed to predict the natural frequencies of continuous-span composite steel bridges. The parametric study results are also compared with existing prediction methods, showing that the proposed equations represent a significant improvement over the existing prediction methods.     

Structural details of steel girder–abutment joints in integral bridges: An experimental study

Integral bridges, which have integrated superstructures and substructures, should essentially maintain the rigid behavior and structural safety of the various existing joints. Especially temperature sensitive, girder-abutment joints for integral steel bridges are steel–concrete composite structures and require sufficient rigid behavior. Yet, various design guidelines and standards do not state these specific designs or construction methods. This study proposes structural details of girder-abutment joints in integral steel bridges for enhanced rigid behavior and load-resisting and crack-resisting capacity. Thus, this study additionally suggests various joints that apply stud shear connectors and perfobond rib shear connectors to existing empirically constructed girder-abutment joints. This study verifies the performance and evaluates the behavior of the proposed steel girder-abutment joints through experimental loading tests of empirically constructed joint specimens and specimens of the proposed joints. Also, this study performs FE analysis (non-linear structural analysis), which applies contact interaction of the interface of the steel–concrete composite joints. As a result of the experimental loading test, all the existing empirical joints and the proposed joints demonstrated sufficient rigidity and crack-resisting capacity under required design and yield load and are applicable as girder-abutment joints for integral steel bridges. Moreover, the proposed joints are judged to be structurally superior to the empirically constructed joints by the results of analysis for load-displacement relationships, crack-propagation behaviors, and load-strain relationships. Like the proposed girder-abutment joints in this study, joints with improved rigid behavior and load-resisting and crack-resisting capacity may resolve and properly control durability and serviceability issues of integral bridges.     

Time-variant reliability profiles for steel girder bridges

Evaluation of existing steel bridges becomes more important due to natural aging, increasing load spectra, deterioration caused by corrosion, and other problems. In the result, bridge structures exposed to aggressive environmental conditions are subjected to time-variant changes of resistance. Therefore, there is a need for evaluation procedures for an accurate prediction of the load carrying capacity and reliability of bridge structures, in order to make rational decisions about repair, rehabilitation, and expected life-cycle costs. The objective of this paper is to develop time-variant reliability models for steel girder bridges. Traditional methods based on deterministic analysis do not reveal the actual load carrying capacity of the structure. The proposed approach is based on reliability analysis of components and structural systems. The study involves the selection of representative structures, formulation of limit state functions, development of load models, development of resistance models for corroded steel girders, development of the reliability analysis method, reliability analysis of selected bridges, and development of the time-dependant reliability profiles including deterioration due to corrosion. The results of the study can be used for a better prediction of the service life of deteriorating steel girder bridges, and development of optimal reliability-based maintenance strategies.     

混合式桥型对超长跨桥梁的适应性

本文对中跨为2500m的混合型斜拉悬索桥的进行了初步设计,构想了三种斜拉悬索桥和一种悬索桥桥式。从初步设计结果中比较它们上部结构钢材的重量发现,考虑到下部结构尺寸,斜拉悬索桥相对悬索桥具有优越性。另外,对这几种型式的桥梁进行了抗弯稳定性分析以及耦合颤振分析。分析结果表明,斜拉悬索桥抗弯稳定性是足够的,而且其临界风速高于悬索桥的临界风速。所以,作者认为针对超长跨度桥梁混合型斜拉悬索桥赛过悬索桥     

Stability evaluation of steel girder members in long-span cable-stayed bridges by member-based stability concept

The member-based design concept utilizing the buckling length of each structural member has been widely used to assess the buckling instability of steel structures. Since steel girder members in conventional cable-stayed bridges are generally exposed to large axial forces, the buckling instability of these members should be carefully investigated in the design stage. However, analytical approaches for obtaining the buckling lengths of steel members, such as the alignment chart, story-buckling and story-stiffness methods, may not be adopted to cable-stayed bridges because these approaches imply some theoretical assumptions that are adequate only for steel framed-structures. Furthermore, the boundary conditions of steel girder members supporting by cables are obscure to be prescribed in general terms. Numerical eigenvalue analysis may be one of the most excellent candidates for determining the buckling lengths of steel girder members in that this method can handle the interactions among members implicitly without any irrelevant assumptions for cable-stayed bridges. This paper discusses detailed procedures for obtaining buckling lengths of steel girder members in cable-stayed bridges by numerical eigenvalue analysis. In order to avoid the problem of generating excessively large buckling lengths in some girder members having small axial forces, a modified eigenvalue analysis is proposed by introducing the concept of a fictitious axial force. Practical application example for a real cable-stayed bridge is illustrated with some discussions on the effect of the proposed modification and stability evaluation by member-based stability concept.     

Mechanical behavior and analysis of composite bridges with corrugated steel webs: State-of-the-art

The composite bridges with corrugated steel webs have excellent properties, such as lightness of girders, efficiency of introducing prestress forces, short construction period, optimum force distribution, good seismic performance, and aesthetics appearance etc., which have greatly promoted the application of such bridges. The objective of this paper is to provide and summarize important references related to the analysis, design and construction of composite bridges with corrugated steel webs. Subjects discussed in this review include (1) structural configuration and application; (2) shear behavior; (3) bending behavior; (4) torsional behavior; (5) patch loading resistance; (6) dynamic behavior; (7) long-term behaviors including fatigue and creep; (8) component connections; (9) analysis method and theory; (10) new concept application. The literature survey presented herein mainly focuses on papers written in English, Japanese, German and Chinese in relation to composite bridges with corrugated steel webs.