Taizhou Yangtze River Bridge——The first kilometer level three-pylon two-span suspension bridge in the world

Taizhou Bridge, located at the middle of Jiangsu Province, connecting Taizhou City and Zhenjiang City, started in Dec. 2007. The bridge is the first kilometer level three-pylon suspension bridge in the world, and it adopts longitudinal herringbone shape steel middle pylon for the first time in the world. The foundation of the middle tower is the deepest underwater caisson in soil on earth. A great many of technical innovations such as the design techniques of three-pylon suspension bridge,precisely locating and bottom-sealing techniques of the large scale caisson foundation, manufacturing, combination techniques of steel and concrete in the middle tower, welding of extra thick steel plate, manufacture and control techniques of abnormal sections of the middle tower and so on were introduced.

三塔两跨悬索桥中央扣静力影响研究

中央扣常用于减少大跨悬索桥缆、梁之间的纵向相对位移。对于三塔两跨地锚悬索桥,中央扣对结构受力有更大影响。为了揭示中央扣对三塔两跨地锚悬索桥的静力影响、内在机理,以泰州长江公路大桥为基础,通过多个有限元模型的计算分析比较,研究了不同中央扣设置情形对中塔、主缆、加劲梁受力的影响。研究表明:三塔两跨地锚悬索桥的水平纵向索、双中央扣构造使得缆、梁、中塔间形成更直接的传力通道,减少了中塔上塔柱承担的活载剪力,对中塔内力位移、中塔处主缆抗滑安全、加劲梁弯矩均有较大改善。

Optimizing control of a two-span rotor system with magnetorheological fluid dampers

A control system aims at vibration reduction in a two-span rotor system with two shear mode magnetorheological （MRF） dampers is designed. A finite element model of the MRF damper- rotor system is built and used to analyze the rotor vibration characteristics. Based on Hooke and Jeeves algorithm and the numerical simulation analysis, an optimal appropriate controller is proposed and designed. Experimental results show that rotor vibration caused by unbalance is well controlled （ first critical speed region 37% , second critical speed region 42% ）. To reflect advantages of optimi- zing strategy presented and validate the intelligent optimization control technology, detailed experi- ments were developed on a two-span rotor-vibration-control platform. The influence on accuracy, rapidity and stability of optimizing control for rotor vibration are analyzed. It provides a powerful technical support for the extension and application in target and control for shafting vibration.

三塔双跨悬索桥动力特性分析

桥梁结构的动力特性对进行桥梁的动力性能设计、健康检测和维护具有十分重要的意义,而三塔双跨悬索桥具有和传统的大跨径悬桥不完全相同的静、动力性能。针对泰州大桥工程实例,通过ANSYS有限元分析软件研究了三塔双跨悬索桥在成桥阶段和施工阶段的动力特性,并与传统的悬索桥作比较,得出了一些有意义的结论,供工程设计人员参考。

Scaled down model design of shaking table test of Taizhou Bridge

Taizhou Bridge is the first kilometer level three-pylon two-span suspension bridge in the world and the structural complexity has significant effects on the seismic performance of the bridge. Shaking table test of Taizhou Bridge is arranged to investigate the effects of non-uniform ground motion input, collision between main and side spans and optimal seismic structural system. It's very important and difficult to design and manufacture the scaled down model of Taizhou Bridge used during the shaking table test. The key point is that the girder and pylons are very hard to be manufactured if the similarity ratio is strictly followed. Based on the finite element method (FEM) analysis, a simplified scaled down model is designed and the bending stiffness of the girder and pylon are strictly simulated, and the torsion stiffness and axial stiffness are not strictly simulated. The inner forces and displacements of critical sections, points of simplified model and theoretical model are compared by FEM analysis, and it's found out that the difference between the seismic responses is relatively small. So, the simplified model can be used to conduct the shaking table test by the FEM verification.

Research on key technologies in design of middle pylon of Taizhou Bridge

At the middle pylon of a three-pylon two-span suspension bridge, the effect of unbalanced loads on the adjacent spans may result in a series of technical bottlenecks in design, such as stability and anti-slippage between saddles and main cables. This article presents the researches conducted on structure selection and behavior characteristics of middle pylon, interaction mechanism between main cables and saddles and their anti-slippage safety performance, elastic and plastic stability analysis and safety assessment of steel middle pylon, and fatigue design load and method for steel pylon of Taizhou Bridge. According to the research results, a longitudinal inverted Y shape steel middle pylon is used in design, effectively solving many technical difficulties, and this type of pylon has become a suitable middle pylon structural form for many three-ovlon two-soan susoension bridges.

泰州大桥的技术创新与突破

文章介绍了世界首座千米级三塔两跨悬索桥-泰州大桥的技术创新和技术突破。为解决泰州大桥由于其全新的结构体系带来的技术挑战,开展了多塔连跨悬索桥结构体系与结构性能、深水大型沉井关键技术、多塔悬索桥中间塔制造与安装关键技术、三塔悬索桥上部结构施工关键技术等多项科技攻关,攻克了多塔连跨悬索桥建造关键技术,实现了悬索桥建设的全新突破。

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.

Nonlinear Vibrations of Two-Span Composite Laminated Plates with Equal and Unequal Subspan Lengths

The nonlinear transverse vibrations of ordered and disordered twodimensional(2D)two-span composite laminated plates are studied.Based on the von Karman’s large deformation theory,the equations of motion of each-span composite laminated plate are formulated using Hamilton’s principle,and the partial differential equations are discretized into nonlinear ordinary ones through the Galerkin’s method.The primary resonance and 1/3 sub-harmonic resonance are investigated by using the method of multiple scales.The amplitude-frequency relations of the steady-state responses and their stability analyses in each kind of resonance are carried out.The effects of the disorder ratio and ply angle on the two different resonances are analyzed.From the numerical results,it can be concluded that disorder in the length of the two-span 2D composite laminated plate will cause the nonlinear vibration localization phenomenon,and with the increase of the disorder ratio,the vibration localization phenomenon will become more obvious.Moreover,the amplitude-frequency curves for both primary resonance and 1/3 sub-harmonic resonance obtained by the present analytical method are compared with those by the numerical integration,and satisfactory precision can be obtained for engineering applications and the results certify the correctness of the present approximately analytical solutions.