考虑腹板屈曲后强度的钢梁设计方法

提出了按考虑腹板屈曲后强度的方法设计钢梁时,钢梁试选截面的设计方法。算例表明,用该建议的方法设计,初选截面一次就能通过截面验算,并且一般能得到用钢量较少的优良截面。

网络逻辑思想在钢梁设计教学中的应用

对网络逻辑思想进行了介绍,并阐述其在钢梁设计教学中的应用,指出网络逻辑思想可以使得学生在学习过程中对概念更加清晰,思路更加逻辑化,大大增强了教学效果,提高了学习效率。

超重级别基桩静荷载试验堆载钢梁设计与优化

以超重级别52000kN的基桩静压荷载试验工程为例,对堆载钢梁进行受力分析,并进行了强度计算、稳定性等验算。按规范相关要求进行计算与设计,采取相应构造措施,并对钢梁采用变截面优化对比设计,达到经济适用、安全可靠的效果,从而为今后类似工程提供实践参考。

九江桥钢梁设计安全可靠度初探

九江长江大桥钢梁设计的安全可靠度问题,曾引起了许多人的关注。本文从15MnVN钢的技术性能、可焊性的各种试验结果,论述了优化后的15MnVN钢优于日本相类似的钢种SM58:对杆件的最大焊接板厚采用δ=56mm是否允许、疲劳允许应力的取值、总体稳定及局部稳定计算公式的安全度等问题,都作了一定深度的论述和探讨。并与日本本州——四国联络桥采用的相应计算公式作了较为详细的比较,从另一角度提出了对九江桥钢梁设计的安全可靠度的见解。

铁路框构顶进工程接触网支架改移方案设计

某框构顶进工程中,由于框构结构较宽,需要改移接触网支柱,但常规设计的接触网尺寸无法满足工程需要。结合接触网的技术特点和钢梁的受力特点,设计了一个跨度达到76 m的钢梁,并对该钢梁的强度、挠度和稳定性进行了分析,计算表明该设计是可行。

大悬挑型钢模架和外架相结合技术设计与施工

对闽西"长汀某广场一期A组团"高层住宅小区斜屋面和天沟结构模板支撑架与施工外架相结合的施工方法进行了介绍,施工采用斜拉钢丝绳悬挑型钢,其悬挑型钢梁悬挑长度超过3 m,属大悬挑结构须专门设计和论证,该施工技术方案解决了高层悬挑承重架的搭设难题,为其他类似工程结构的施工提供了参考。

大型斜拉桥钢锚梁快速精确定位技术研究

大型斜拉桥建设施工中,由于钢锚梁高程定位区域受到限制,容易导致定位坐标发生偏差等问题,为此开展对大型斜拉桥钢锚梁快速精确定位技术的设计研究工作。根据斜拉桥钢锚梁定位需求及设定标准,通过布设施工控制网对首节钢锚梁进行定位,采用多目标形式扩大实际定位区域和完成高程传递处理,采取归化法实现快速精准定位。测试结果表明:经过三个位置钢锚梁的定位测试,获取的定位偏差值都控制在2.5mm以下,说明该技术的定位精度和速度更快且误差可控,具有较高的应用价值。

Design of the Composite Steel-Glass Beams with Semi-Rigid Polymer Adhesive Joint

New and high transparent structural element, steel-glass composite beam was developed in respect to fabrication, static-structural and architectural criteria and consists of steel flanges and glass web assembled together by semi-rigid polymer adhesive, which is the key element of whole composite system. These beams can be used mainly as members of high transparent roof or floor structure as well as stiffening fins for large area glass facades. This paper deals with experimental research performed at CTU （Czech Technical University） Prague, which started by adhesive selection and initial material tests by ISO527, continued via small-scale steel-glass connection tests and graduated by full-scale tests of hybrid beams with the span of 4 m. Generalized results of these experiments, analytical and numerical studies serve as device, how to accurately predict the behavior of the beam, describe the stress distribution along the cross section and safely and economically design such a kind of structure with semi-rigid shear connection, made by polymer adhesive.

Design methods of headed studs for composite decks of through steel bridges in high-speed railway

Aimed at two typical composite floor systems of through steel bridges in high speed railway,design methods of headed studs were put forward for different composite members through comparing and analyzing the structure,mechanical characteristics and transmission routes of deck loads.The simplified calculation models were brought out for the stud design of the longitudinal girders and transverse girders in the composite floor system of Nanjing Dashengguan Yangtze River Bridge (NDB).Studs were designed and arranged by taking the middle panel of 336 m main span for example.The results show that under deck loads,the longitudinal girders in the composite floor system of through steel bridges are in tension-bending state,longitudinal shear force on the interface is caused by both longitudinal force of "The first mechanical system" and vertical bending of "The second mechanical system",and studs can be arranged with equal space in terms of the shear force in range of 0.2d (where d is the panel length) on the top ends.Transverse girders in steel longitudinal and transverse girders-concrete slab composite deck are in compound-bending state,and out-of-plane bending has to be taken into account in the stud design.In orthotropic integral steel deck-concrete slab composite deck,out-of-plane bending of transverse girders is very small so that it can be neglected,and studs on the orthotropic integral steel deck can be arranged according to the structural requirements.The above design methods and simplified calculation models have been applied in the stud design of NDB.

Applications of Glass and Glass Fiber Retrofit Polymer in Modern Footbridges

The architecture of footbridge design takes the form of a number of submissions from leading architects and engineers, each setting out their views on bridge design--present and future. It looks at the functions of a bridge, defining purpose of place and context, the spirit of creativity and the reasoned progression of an idea. It also explores the exploitation of materials technology and construction innovation and the tension between lightness and mass and between sculpture and scale. Present parameters of tempered and laminated glass create possibility of modern architecture of footbridges which are being full of transparency and light reflex effects. Four projects, using glass panels designed by Santiago Calatrava, have been presented in this paper. GFRP （glass fiber retrofit polymer） makes new horizon in material technology, helps to enrich new conception of structure with longer durability, low weight of deck and new creation of architecture line. The paper has described a few results of FEM （finite element method） analysis of footbridge with modular bridge GFRP deck system. The footbridge was excited by impact and human-induced vibrations. Composite material consists of glass fibers and polymer matrix is a promising alternative against traditional materials. New architecture and modern material engineering are looking for fresh possibilities of form and shape of structure, long durability and extraordinary technical parameters of building elements.

A Method to Improve First Order Approximation of Smoothed Particle Hydrodynamics

Smoothed particle hydrodynamics (SPH) is a useful meshless method.The first and second orders are the most popular derivatives of the field function in the mechanical governing equations.New methods were proposed to improve accuracy of SPH approximation by the lemma proved.The lemma describes the relationship of functions and their SPH approximation.Finally,the error comparison of SPH method with or without our improvement was carried out.

Study in the design and manufacture process of the elastic cable anchor box in steel box girder of Taizhou Bridge

Taizhou Yangtze River Highway Bridge is a large span suspension bridge with three pylons. The elastic cables are installed to connect the steel tower and the steel box girder. The constraints can increase the safety coefficient of the middle saddle, and improve the stress conditions of the middle pylon and decrease the deflection in the middle of the main girder, as well as the longitudinal displacement of the main girder caused by live loads. The anchorage boxes of the elastic cable are installed in the wind fairing outside the vertical web plate of the box girder. Two anchor boxes form a pair and are arranged parallelly. Eight anchor boxes are installed in the bridge. In this paper, the design scheme and the technical difficulties in manufacturing are briefly discussed with the precision control techniques.

Design of steel box girder for Taizhou Yangtze River Highway Bridge

Taizhou Yangtze River Highway Bridge is the first three-pylon two-span suspension bridge in China. The main girder adopts flat steamline steel closed box girder which has well wind-resistant capability and is technically mature besides beautiful appearance. Straight web plates of the steel box girder in longitudinal direction are proposed in order to ensure the integrity of the steel box girder, and to keep the stress of the steel box girder continuous in the middle pylon, as well as to reduce the gradient of the middle pylon columns. The cross section of the box girder has one box with three cells. Solid-web diaphragm plate with good integrity and high torsional stiffness is adopted. The lifting lugs are utilized in the anchors of suspender cable. In this paper, selection of the cross section of the steel box girder, the general structure design, local structure design and main structure calculation results of Taizhou Yangtze River Bridge are introduced emphatically.

Gao Zongyu:Engineer and Designer of World-class Bridges

PLANNED in 2003,construction of the 1,092-meter-long ShanghaiNantong Railway Yangtze River Bridge–the world’s longest rail-cumroad cable-stayed steel bridge–started in 2014.On completion in 2019,it will span the 130 km.between the two cities,shortening to one hour the drive from Shanghai to Nantong.

Distribution of Reinforcement in Tensile Flanges of Concrete T-shape Continuous Beam

In this paper the analysis of tensile stress distribution in flexural continuous T- beam has been presented. The observed damages in carrying deck of RC bridge over the Wieprz River in Baranow indicate that over pillar zones are not protected enough. The results of numerical analysis have shown that tensile stress in T- section beam appears not only in a web but in flanges as well. Thus reinforcing bars should be distributed within the whole effective width. This fact is mentioned in building codes, for example, in Eurocode 2： ＂Design of concrete structures＂, both in part 1.1 ＂General rules and rules for building＂ and in part 2 ＂Reinforced and prestressed concrete bridges＂, but there are not detailed rules how to place the bars in flanges of T-section.

新中国名片:南京长江大桥

建成于1968年的南京长江大桥，连接着津浦、沪宁两条铁路以及苏南苏北的公路，是长江上第一座由我国自力更生设计建造的双层双线式铁路、公路两用桥，建成后曾以“最长的公铁两用桥”载人《吉尼斯世界纪录大全》。南京长江大桥未通车前，从下关坐渡轮去浦口需两个小时；通车后，只需要5分钟，两岸经济迅速增长，进入“大桥时代”。为了更好地保护它，南京正酝酿将长江大桥申报全国重点文保单位，力争让其成为中国最年轻的“国保”。