基于参数化的中小跨径桥梁标准检修装置研究

针对目前桥梁检修系统设计现状与实际运营需求的差距,提出了一种适用于中小跨径桥梁的通用检修装置系统,并研究了该套检修装置的参数化设计和标准化施工方法,编制了一套基于三维可视化设计的检修装置参数化通用图,其方法可供类似桥梁养护设施设计参考。     

热轧H型钢钢混组合梁在中小跨径公路桥梁中的应用实践

热轧H型钢在公路桥梁中国内应用案例极少,文章列举了两座热轧H型钢钢混组合梁在中小跨径桥梁中的设计应用实践案例,探索了热轧H型钢钢混组合梁在公路中小跨径桥梁中的设计方法,为钢结构在中小跨径桥梁中的应用推广提供借鉴。     

山区中小跨径桥梁设计原则及要点

山区桥梁工程建设难度系数较高,且受地形条件的影响较大,所以主要设计成中小跨径桥梁。本文根据山区中小跨径桥梁工程,简要介绍了设计基本原则,然后从上部结构、下部结构以及结构基础等方面研究了中小跨径桥梁设计要点,从而为类似桥梁工程设计提供指导与参考。     

中小跨径桥梁常规上部结构技术经济指标分析

在调查研究、计算基础上,对高速公路桥梁、城市立交—高架体系中小跨径桥梁常规上部结构的技术经济指标进行了比较,从而提出了中小跨径桥梁常规上部结构经济形式。以利于降低工程造价,提高项目收益率,推进桥梁建设项目管理、设计施工标准化。     

变宽度组合梁套用交通部工字组合梁钢桥通用图的设计调整

目前工字组合梁钢桥在预制拼装桥梁中应用广泛,随着交通部工字组合梁钢桥通用图的发布,对提高常规跨径等宽工字组合梁钢桥的设计技术水平起到了重要的规范和指引作用。但通用图仅适用于（2×12.75）m和（2×16.5）m 2种桥宽,灵活性不高,尤其缺乏变宽度情况下的研究。通过研究典型变宽段组合梁的桥面板设计和主梁布置,探讨应用通用图存在的问题,并从增加桥面板适用跨径、减小横梁应力集中、优化支反力分布等多方面提出优化措施,能使组合桥梁适应变宽情况和增加通用图的适用性。这对于工字组合梁钢桥通用图的全面推广应用提供有意义的探索和参考。     

土木与建筑领域的计算机协同工作--第十届国际土木与建筑工程计算机应用学术会议新进展

第十届国际土木与建筑工程计算机应用学术会议于2004年6月在德国召开。对会议的中心议题“土 木与建筑领域的计算机协同工作”进行了介绍,并结合作者在研制“西部地区中小跨径桥梁通用图形库”中取 得的经验,对计算机协同工作的研究现状和发展趋势进行了分析,最后通过实例对计算机协同系统的开发技 术进行了分析。     

中小跨径桥梁的经济性分析

中小跨径桥梁是桥梁设计是中占比最大、应用最广的桥型结构,如何选择最经济的中小跨径桥梁,是每位建设者都关心的问题。本文通过对空心板、小箱梁、T梁、钢混组合结构四种最常见的上部结构形式以及在联长相同情况下不同跨径和墩高组合的T梁方案的经济性分析对比,得到相比较而言较经济的结构形式和跨径墩高组合,以为建设者选择上下部结构提供参考。     

现代桥梁设计理念与技术创新

桥梁建设向大跨径、深水域、近海和崇山峻岭发展,面临着巨大的技术挑战。在回顾了苏通大桥等一批桥梁的技术难点之后,归纳总结了大跨径桥梁的技术创新,提出了大跨径桥梁的关键技术问题,针对量大面广的中小桥梁提出了集成设计的理念;分析了桥梁防灾减灾技术的热点问题;探讨了桥梁结构健康监测及养护的策略。     

基于动态称重数据的中小跨径公路桥梁车辆荷载模型研究

以某中小跨径公路桥梁为工程背景，基于动态称重（Weight in Motion,WIM）系统实测数据建立了该桥梁的车辆荷载模型。结果表明，该桥梁实际车辆荷载为设计荷载的1.18倍，外推100年设计基准期车辆荷载计算结果为设计荷载的1.62倍。所提供的研究方法对桥梁车辆荷载模型的建立具有一定的借鉴意义。     

碳纤维布在中小跨径桥梁上部结构加固中应用

结合具体工程实例,介绍了碳纤维布加固中小跨径桥梁上部结构的处治方案和加固机理,分别阐述了该工艺的计算方法、设计要点、材料及施工方法等,对于同类桥梁的加固具有指导作用和推广价值。     

ObjectARX在桥梁预应力钢索施工图中的应用

针对桥梁设计施工的标准化、规范化特点,对桥梁参数化绘图方法进行了研究,并以预应力钢索布置图为例,采用AutoCAD ObjectARX二次开发技术,选择稳定高效的AutoCAD平台对桥梁CAD绘图系统进行开发,从而参数化绘制桥梁施工图,实现在AutoCAD中直接出图的目的,提高桥梁设计绘图的质量和效率。     

An Approach to Preliminary Design of Precast Pretensioned Concrete Bridge Girders

Abstract: This paper presents an approach to the preliminary design of simple span precast pretensioned highway bridge girders using mathematical optimization methods. This type of bridge system is competitive for short and medium spans but also can accommodate long-span bridges if girder splicing and continuity are introduced. The bridge design problem is formulated as a nonlinear programming problem and is solved by the projected lagrangian algorithm. Several design objectives are investigated either separately or simultaneously with the aim of achieving cost-efficient bridge designs. The approach is used to generate a new set of five optimal girder sections and then to determine the girder spacing and span length capability of each precast girder. The five sections types (A, B, C, D, and E) proposed herein are more cost-effective than the corresponding Canadian standard sections because for similar depths they achieve greater span length and girder spacing while requiring less concrete and prestressing steel. This study also enables identification of the governing design requirements (serviceability and/or ultimate limit states active constraints) that may be adopted as optimality criteria when simplified preliminary designs of this bridge type for different design codes and girder sections are required.     

Frontier of continuous structural health monitoring system for short & medium span bridges and condition assessment

It is becoming an important social problem to make maintenance and rehabilitation of existing short and medium span(10-20 m) bridges because there are a huge amount of short and medium span bridges in service in the world. The kernel of such bridge management is to develop a method of safety(condition) assessment on items which include remaining life and load carrying capacity. Bridge health monitoring using information technology and sensors is capable of providing more accurate knowledge of bridge performance than traditional strategies. The aim of this paper is to introduce a state-of-the-art on not only a rational bridge health monitoring system incorporating with the information and communication technologies for lifetime management of existing short and medium span bridges but also a continuous data collecting system designed for bridge health monitoring of mainly short and medium span bridges. In this paper, although there are some useful monitoring methods for short and medium span bridges based on the qualitative or quantitative information, mainly two advanced structural health monitoring systems are described to review and analyse the potential of utilizing the long term health monitoring in safety assessment and management issues for short and medium span bridge. The first is a special designed mobile in-situ loading device(vehicle) for short and medium span road bridges to assess the structural safety(performance) and derive optimal strategies for maintenance using reliability based method. The second is a long term health monitoring method by using the public buses as part of a public transit system (called bus monitoring system) to be applied mainly to short and medium span bridges, along with safety indices, namely, “characteristic deflection” which is relatively free from the influence of dynamic disturbances due to such factors as the roughness of the road surface, and a structural anomaly parameter.     

桥位风场特性研究方法探讨

在桥梁设计过程中,特别是初步设计阶段,准确获得大跨径桥梁桥位风场特性参数非常重要。本文以临猗黄河特大桥桥位处风场特性研究为背景,采用数值模拟和风场实测方法对风场特性进行研究。结果发现,风场实测位置处10m、30m、50m、80m高度的平均风速分别为2.7m/s、3.4m/s、3.9m/s、4.4m/s,数值模型对应位置处相同高度的风速计算值分别为2.90m/s、3.24m/s、3.55m/s、3.94m/s,误差分别为7.4%、-4.7%、-9.0%、-10.5%,计算结果满足工程需求。对处于复杂地形特别是峡谷谷口的大跨径桥梁,在初步设计阶段通过数值模拟方法获得桥位处风速数据的方法具有可行性。     

智能化结构平面施工图软件的研究

论述了研制智能化结构平面施工图软件的必要性,并对结构平面施工图的内容、难题和涉及的相关规范以及设计过程及特点进行剖析、研究,提出了实现智能化结构平面施工图中要解决的关键问题及解决方法。     

协同式桥梁抗震CAD系统设计

协同设计是工程设计发展的必然趋势,协同设计的思想和传统的桥梁抗震CAD系统的开发兰程相结合设计协同式桥梁抗震CAD系统,不仅可以提高桥梁抗震设计的效率,而且也反映了桥梁抗震设计的本质。首先完成了协同式桥梁抗震CAD系统结构设计．然后在此基础上对数据管理层和应用程序层的实现进行了研究,取得了初步的成果。     

中小跨径桥梁结构挠度监测技术试验研究

对于中小跨径桥梁结构,在分析其挠度感知特点及需求的基础上,通过典型桥梁结构现场试验提出一种基于差动变压原理的挠度测试新方法.试验时在梁体跨中分别布设3类传感设备——机电百分表、挠度沉降仪、差动变压器式位移传感器LVDT,分别测试3类传感设备测试结果的准确性.试验结果表明,对于中小跨径桥梁,机电百分表和挠度沉降仪测试的挠度变形偏差较大,LVDT的测试挠度变形偏差很小,能够满足挠度变形的实时、在线、准确测定.     

刚接空心板在中小跨径桥梁中的应用

装配式预应力混凝土空心板因其具有的诸多优点在中小跨径、等宽、直线桥中被广泛应用。但是如果板与板间横向连接方式设计不当,会造成结构使用过程中的病害,实际受力与计算假定不符,甚至造成单板受力情况的发生。本文结合某中小跨径跨河桥,以20m跨径的空心板为例,采用Midas Civil进行梁格法建模。从桥型布置、结构尺寸、截面特性、受力特点、材料指标及经济性等多方面进行对比分析,总结出刚接空心板桥的优越性,并将其应用于工程设计中。     

高校建筑设计教学中CAD技术的应用研究

针对CAD技术在建筑工程设计领域内的迅速发展和应用, 从建筑学专业的角度, 提出CAD技术在建筑教学中存在的问题与改进的措施。为CAD教学和建筑类专业的工程技术人员更好地进行工程绘图提供了更多的参考。     

Investigation of Live Load Deflection Limit for Steel Cable Stayed and Suspension Bridges

Long span bridges such as steel cable stayed and suspension bridges are usually more flexible than short to medium span bridges and expected to have large deformations. Deflections due to live load for long span bridges are important since it controls the overall heights of the bridge for securing the clearance under the bridge and serviceability for securing the comfort of passengers or pedestrians. In case of sea-crossing bridges, the clearance of bridges is determined considering the height of the ship master from the surface of the water, the trim of the ship, the psychological free space, the tide height, and live load deflection. In the design of bridges, live load deflection is limited to a certain value to minimize the vibrations. However, there are not much studies that consider the live load deflection and its effects for long span bridges. The purpose of this study is to investigate the suitability of live load deflection limit and its actual effects on serviceability of bridges for steel cable-stayed and suspension bridges. Analytical study is performed to calculate the natural frequencies and deflections by design live load. Results are compared with various design limits and related studies by Barker et al. (2011) and Saadeghvaziri et al. (2012). Two long span bridges are selected for the case study, Yi Sun-Sin grand bridge (suspension bridge, main span length?=?1545 m) and Young-Hung grand bridge (cable stayed bridge, main span length?=?240 m). Long-term measured deflection data by GNSS system are collected from Yi Sun-Sin grand bridge and compared with the theoretical values. Probability of exceedance against various deflection limits are calculated from probability distribution of 10-min maximum deflection. The results of the study on the limitation of live load deflection are expected to be useful reference for the design, the proper planning and deflection review of the long span bridges around the world.