Design and stability analysis of continuous skew tied-arch bridge over Bin Jiang River

A tied arch bridge without wind bracing was built over the Bin Jiang River, with oblique angle of 20°. Its main design details are described and mechanical performances are analyzed. The stability analytical types are also introduced and the first elastic stability theory is used. A space finite element model has been built to analyze the stability performances in both construction and operation stages for single span or continuous, orthogonal or oblique bridge. The influence of stiffness of the end crossbeam is also analyzed. The result shows that out-plane buckling occur for a rigid tie and similar no matter whether it is single span or continuous and orthogonal or oblique. When there are more and stronger inner crossbeams, the influence of the end crossbeams on arch stability becomes unremarkable.     

Ribbon bridge in waves based on hydroelasticity theory

For the design and operation of a floating bridge, the understanding of its hydroelastic behavior in waves is of great importance. This paper investigated the hydroelastic performances of a ribbon bridge under wave action. A brief introduction on the estimation of dynamic responses of the floating bridge and the comparisons between the experiments and estimation were presented. Based on the 3D hydroelasticity theory, the hydroelastic behavior of the ribbon bridge modeled by finite element method (FEM) was analyzed by employing the mode superposition method. And the relevant comparisons between the numerical results and experimental data obtained from one tenth scale elastic model test in the ocean basin were made. It is found that the present method is applicable and adaptable for predicting the hydroelastic response of the floating bridge in waves. __________ Translated from Journal of Shanghai Jiaotong University, 2007, 41(9): 1441–1444 [译自: 上海交通大学学报]     

宁波市湾头大桥拱肋弦杆制孔工艺

宁波市湾头大桥主桥是3跨连续钢桁架拱桥,主桥拱肋由2片桁架和6道风撑组成,桥面系为采用主梁、横梁、纵梁的框架结构体系。拱肋杆件的曲线线形、构件之间连接关系复杂、部分构件超高、超宽、超长等是该桥的主要特点和难点。针对宁波市湾头大桥的结构特点,对拱肋上下弦杆在制造过程中合理采用杆件整体划线制孔、以直代曲等工艺,解决单个拱肋杆件孔群精度以及整个曲线拱线形等难题,取得良好效果。     

非对称外倾式钢箱拱桥结构与施工

介绍了世界上首座大跨径曲线梁非对称外倾拱桥——南宁大桥的结构特点,阐述了“先拱后梁、以拱承梁,钢肋拱通过斜拉扣挂悬臂拼装”的施工方案。实践证明,此施工方法是成功、可行的,在此指导下,为增加拱肋纵横向稳定性而设置的临时系杆、临时吊杆、临时横梁以及缆风索对整个外倾式结构的安装安全和保证质量起到关键性的作用,为今后同类型的桥梁提供良好的借鉴经验。     

Limit span of self-anchored cable-stayed suspension cooperation system bridge based on strength

The limit span of self-anchored cable-stayed suspension bridge is deduced. The relations among the geometrical parameters, loads and material characteristics are also analyzed. Based on the material strength and commonly used materials, the limit spans of self-anchored cable-stayed suspension bridges with concrete girder or steel girder under vertical static load are discussed in detail. The corresponding upper limit spans and the effect of the factors on the span are given. The results indicate that increasing rise-span ratio, height-span ratio and cable-stayed segment length or reducing the second dead load could increase the cooperation system span. __________ Translated from Journal of Dalian University of Technology, 2008, 48(3): 387–391 [译自: 大连理工大学学报]     

Calculation method on shape finding of self-anchored suspension bridge with spatial cables

Based on the spatial model, a reliable and accurate calculation method on the shape finding of self-anchored suspension bridge with spatial cables was studied in this paper. On the principle that the shape of the main cables between hangers is catenary, the iteration method of calculating the shapes of the spatial main cables under the load of hanger forces was deduced. The reasonable position of the saddle was determined according to the shape and the theoretical joint point of the main cables. The shapes of the main cables at completed cable stage were calculated based on the unchanging principle of the zero-stress lengths of the main cables. By using a numerical method combining with the finite element method, one self-anchored suspension bridge with spatial cables was analyzed. The zero-stress length of the main cables, the position of the saddle, and the pre-offsetting of the saddle of the self-anchored suspension bridge were given. The reasonable shapes of the main cables at bridge completion stage and completed cable stage were presented. The results show that the shape-finding calculation method is effective and reliable. __________ Translated from Journal of Hunan University (Natural Sciences), 2007, 34(12): 20–25 [译自: 湖南大学学报(自然科学版)]     

General framework for bridge life cycle design

Based on a detailed illustration for bridge life cycle design which comprises the processes of service life design, aesthetics design, performance design, environmental and ecological design, inspection, maintenance and repair design as well as cost analysis, this paper presented a general framework for bridge life cycle design comprising three design phases and six design processes. __________ Translated from Journal of Tongji University (Natural Science), 2007, 35 (8): 1003–1007 [译自: 同济大学学报(自然科学版)]     

新世纪台湾桥梁的技术发展与远景-续

3．南投猫罗溪斜张桥（图24、25） 本桥由于路线线形、桥址用地及河川环境等条件限制，呈现桥宽、横坡变化及跨度不等之情形，为符合上述条件，并使本桥达到高效率的结构配设及塑造景观地标，采用了极具特色的钢拱桥塔斜张桥。桥梁宽度17．2m-21．8m，跨径配置为51m＋119m，为一单塔非对称式斜张桥。拱形桥塔极具特色，拱塔高60公尺。     

Comparisons of bridges flutter derivatives and generalized ones

The causes of the nonlinearity of self-excited aerodynamic force of bridge are interpreted from such two aspects as amplitude and wind velocity. The concept of “generalized flutter derivative” is proposed, and its physical meaning is illustrated. The graphs of the generalized flutter derivatives of plate and Sutong Bridge section model are plotted. The characteristics of all generalized flutter derivatives are compared and analyzed, and their superiorities are verified. The results indicate that the physical meaning of generalized flutter derivatives are more explicit compared to the traditional ones. It is more convenient to understand the nonlinearity properties of self-excited aerodynamic force of bridge according to the generalized flutter derivatives graphs with the wind velocity as the horizontal coordinate. __________ Translated from Journal of Wuhan University of Technology (Transportation Science and Engineering), 2008, 32(4): 607–610 [译自: 武汉理工大学学报(交通科学与工程版)]     

A method for examining the seismic performance of steel arch deck bridges

To examine the seismic resistance performance of a steel arch bridge during a strong earthquake, an approach is proposed in this paper to determine the ultimate strain of an arch rib using the static elasto-plastic large deformation theory. A steel fixed-end deck arch bridge with a span length of 200 m was used as an example in this study. The ultimate strain of the arch rib was calculated using the elasto-plastic finite element model. The seismic responses of the arch bridge exposed to strong earthquakes in two and three directions were also simulated. Moreover, the effect of earthquake motion in the lateral direction on the elasto-plastic earthquake response was discussed, and the seismic resistance of the structure was analyzed. The results show that steel arch bridges have preferable seismic resistance under strong earthquake conditions. While lateral earthquake motion has some influence on the damage to an arch bridge, it has little effect on the displacement, axial force, and bending moment responses of the arch rib. It is feasible to examine the seismic performance of the arch bridge by ascertaining the out-of-plane and in-plane earthquake responses of the bridge.     

Dynamic response of a long span suspension bridge and running safety of a train under wind action

A dynamic analysis model of a wind-train-bridge system is established. The wind excitations of the system are the buffeting and self-excited forces simulated in time domain using measured aerodynamic coefficients and flutter derivatives. The proposed formulations are then applied to a long rail-cum-road suspension bridge. The dynamic responses of the bridge and the train under wind action are analyzed. The results show that the lateral and rotational displacements of the bridge are dominated by wind, while the vertical by the gravity loading of the moving train. The running safeties of the train vehicles are much affected by wind. Under wind conditions of 30–40 m/s, the offload factors, derail factors and overturn factors of the train vehicles exceed the safety allowances, to which great attention should be paid. Translated from Engineering Mechanics, 2006, 23(2): 103–110 [译自: 工程力学]     

Field test on temperature field and thermal stress for prestressed concrete box-girder bridge

A field test was conducted to investigate the distribution of temperature field and the variation of thermal stress for a prestressed concrete (PC) box-girder bridge. The change of hydration heat temperature consists of four periods: temperature rising period, constant temperature period, rapid temperature fall period and slow temperature fall period. The peak value of hydration heat temperature increases with the increasing casting temperature of concrete; the relation between them is approximately linear. According to field tests, the thermal stress incurred by hydration heat may induce temperature cracks on the PC box-girder. Furthermore, the nonlinear distribution of temperature gradient and the fluctuation of thermal stress induced by exposure to sunlight were also obtained based on continuous in-situ monitoring. Such results show that the prevailing Chinese Code (2004) is insufficient since it does not take into account the temperature gradient of the bottom slab. Finally, some preventive measures against temperature cracks were proposed based on related studies. The conclusions can provide valuable reference for the design and construction of PC box-girder bridges. __________ Translated from Journal of Huazhong University of Science and Technology (Urban Science Edition), 2007, 24(4): 83–97 [译自: 华中科技大学学报 (城市科学版)]     

不同拱肋形式对无风撑钢管混凝土拱桥的抗震特性影响

无风撑钢管混凝土拱桥有钢管混凝土拱桥具有跨度大、强度高、塑性好、重量轻、便于施工、造型新颖美观等优点,而且在行车时视野开阔,在未来有很好的应用前景.文中以某五连跨无风撑钢管混凝土拱桥为例,针对无风撑钢管混凝土拱桥特点,采用不同拱肋结构布置形式,对其抗震性能进行了对比分析,得出此类拱桥拱肋合理布置形式.     

Investigations concerning seismic response control of self-anchored suspension bridge with MR dampers

To mitigate the seismic response of self-anchored suspension bridges, equations of motion governing the coupled system of bridge-magneto-rheological (MR) dampers subject to seismic excitation are formulated by employing the phenomenological model of MR dampers. A corresponding computer program is developed and employed for studying the seismic response control of a self-anchored suspension bridge with a main span of 350 m. The effect of variable current and number of dampers on seismic response control is investigated. The numerical results indicate the longitudinal displacement of the tower top and bridge girder decrease with the increase in input current and number of MR dampers attached longitudinally at the tower-girder connections, and the internal forces of the tower are effectively attenuated as well. It appears that small electronic current (0.5 A in this study) may sufficiently attenuate the seismic responses for practical engineering applications. __________ Translated from China Civil Engineering Journal, 2006, 39(11): 84–89 [译自: 土木工程学报]     

劲性骨架混凝土拱结构施工阶段的稳定性分析

以实桥为例,建立了空间分析的有限元模型,对大跨径钢管混凝土拱劲性骨架拱桥施工阶段的稳定性进行了线性和非线性分析,得出在施工过程中非线性对稳定性的影响十分显著,计算施工时的稳定系数必须考虑非线性。     

拱结构稳定理论的发展

介绍了拱结构稳定问题的理论，阐述了拱桥极限承载力研究现状，分析了拱桥极限承载力研究中存在的问题，指出了目前研究拱结构稳定理论的发展方向。     

抛物线斜板拱桥的内力计算

当桥与该桥所位路线的障碍物斜交时,为适应线形和行车顺适,常需修建斜桥．抛物线斜桥以其不苛求支承条件与伸缩装置,又具拱式建筑曲线美和古朴大方等优点,为斜桥方案中优先考虑的桥型．但对抛物线斜板拱桥的受力计算尚无成熟理论,使之应用受到限制．对等截面抛物线斜板拱桥的受力情况进行了简要分析,用力法原理和弹性中心法导出了抛物线斜板桥的内力计算公式．     

Application of cable-supported spatial grid in dry coal shed

This paper presented a new structural style cable-supported spatial grid, which was applied in large span dry coal sheds. The influence of configuration of cable on the force of cable and beam, the ratio of beam force to cable force and the deflection of span was investigated, and a rational configuration of cable was obtained. The results show that the cable-supported spatial grid can maximize the use of material strength, and have the advantages of low usage of steel, large span and sufficient headroom. __________ Translated from Journal of Hunan University (Natural Sciences), 2007, 34(2): 29–32 [译自: 湖南大学学报 (自然科学版)]     

拱肋倾角对刚性系杆拱桥受力性能的影响

采用MIDAS/Civil软件系统,以某跨度为96m的刚性系杆拱桥为例,分两种工况研究了该桥在恒载和恒载+活载作用下拱肋倾角变化对该体系桥梁受力性能的影响。研究结果表明:拱肋倾角变化对其自身变形、应力等受力性能影响较大,对结构动力特性及稳定性影响也较大,对系梁影响相对较小;研究表明:在跨度100m左右的刚性系杆拱桥中,设计时的拱肋倾角取值与施工过程中拱肋倾角偏差值应该控制在-3°～2°。研究结果可为同类型的桥梁设计与施工提供参考。     

桥台抗扭刚度及宽跨比对斜交拱桥受力的影响

通过改变桥台抗扭刚度和宽跨比,研究对斜交拱桥受力的影响。比较了1座单孔斜交拱桥和1座双跨斜交拱桥分别在自重荷载和车道荷载作用下的受力特性变化,得出增大桥台刚度能改善斜交拱桥在自重作用下的受力特性,但对单孔斜交拱桥的改善更明显;宽跨比变化对斜交拱桥的受力性能影响不大。