Applied Mechanics and Materials Vols. 638-640

Abstract: It is introduced that three main factors cause geometric nonlinear effects of long span cable-stayed bridge: large displacement effect, cable sag effect, and the combination of bending moment and axial force effect. The iteration method of geometrical nonlinear problem is also introduced. The bridge deformation was calculated by establishing a plane truss finite element model of a long-span single tower cable-stayed bridge under consideration of nonlinearity and compared with that done with linear method. It is concluded that nonlinearity influenced differently to the bending moment of main girder, the displacement of tower root and the vertical displacement of girder.

Abstract: In order to find the impact on longitudinal resistance of continuously welded rails on bridge under different longitudinal resistance of the lines, based on the principle of the interaction between bridge and track, an integrative rail-bridge-pier calculation model of CWR on bridge is developed. Take simple-supported and continuous beam bridge as example to analyze the influence of continuously welded rails on bridge under different line resistance. The result shows that whether simple-supported or continuous beam bridge, the additional expansion forces which conducted by the constant resistance are smaller than the bilinear and power-exponential resistance, and the gap becomes greater as the increasing of the expansion length, and the calculation of the bilinear and power-exponential resistance becomes more and more similar. Besides, the calculation of the braking forces which conducted by the constant resistance is smaller than the bilinear and power-exponential resistance, while the displacement between the rail and beams is bigger, and has exceeded the calculation standard; the breaking joint of rail conducted under different longitudinal resistance is basically the same, but decreased gradually with the maximum line resistance increased.

Abstract: That stayed cables are prone to corrosion fails to draw enough attention of bridge management until corrosion leads to damage of cables. Corrosion is usually allowed to develop for lack of accurate detection method or rather for lack of matured method of assessing tensile capacity of existing stayed cables. The tensile capacity of corroded stayed cables are affected by main factors such as cable specifications, mechanical properties of wires, extent of corrosion, and distribution of corroded wires in stayed cables. The last two factors are especially in need of systematic research. Therefore, this paper, taking advantage of the project of displacing stayed cables of Shimen Bridge, attempts an investigation of the two factors from the following perspectives: The investigation starts with measurement of corroded cable wires of the bridge to understand mechanical property of the wires and then makes an empirical fitting curve according to the mechanical change caused by corrosion. Severely corroded stayed cables are cut into several parts to expose cross sections, every wire in which is numbered for test of corrosion extent. Thus, radial distribution law of corroded cable wires is well examined. In light of the above investigation, a model is proposed to assess tensile capacity of stayed cable based on the series-parallel connection system. To verify practicality of the theory governing the investigation, one specimen made from a corroded stayed cable with the old anchor terminal on one end is tensioned and assessed using the assessing method proposed in this paper to see if the method is applicable to assessment of tensile capacity of other corroded stayed cables.

Abstract: As a statically indeterminate structure, trough girder and arch composite bridge has a complex internal stress, especially the arch foot. The foot is influenced with the thrust of arch rib, the tension of girder and the supporting force. The trough girder section has a serious steric effect due to the poor torsional capacity. Therefore, the stress characteristics of the railway trough girder and arch composite bridge are more complicated. The main research introduces the details of the arch foot of the trough girder and arch composite bridge of Ningqi Railway over Hutong Railway. The finite element program MIDAS/Civil has been adopted to establish a full three-dimensional model and ANSYS has been adopted to establish an elaborate FEM model of the bridge.

Abstract: Bridge-in-a-Backpack is a new type bridge. this study will investigate the interaction of flow under the bridge with the tubes and decking, and recommend Manning’s roughness coefficient for water flow under the composite backbridge system.

Abstract: This paper presents a three-dimensional entity model to analyze the creep effection of PC continuous rigid frame bridge and simulate the impact of longitudinal cracks at the bottom of mian span on the deflection briefly with ANSYS software. The result shows that creep amplifies the deflection of bridge and makes the position of maximum deflection move to the center of mian span. And the longitudinal cracks of mian span don’t make great contribution to the deflection of PC continuous rigid frame bridge directly. Actually, the cracks change the stress state of the bridge’s section, which results in the risk of web cracking and further the stiffness degradation of structure. The stiffness degradation increases the defection of bridge to a great degree finally.

Abstract: In this paper, based on the theory of ship-bridge collision, large-scale finite element software ANSYS is adopted to establish the calculation model of the bridge.According to the specification of our country, the calculation of bridge collision force then compares with the actual situation.Through the calculation of collision force, the ship-bridge collision is transformed into the problem of transient analysis of collision point.This article is mainly to analyze the change of bridge energy and the stress and displacement of main parts of the bridge. Finally, this article puts forward the personal vision.

Abstract: The anti-seismic measures is effective in reducing the seismic damage of bridge, unseating prevention device is an effective structural measure to prevent collapse under unexpected earthquake, and its parameter will affect the function of unseating prevention devices. Based on relational design standards, the damage-reduction seismic performance of unseating prevention devices with variational design parameter have been analysis. The research results show that the unseating prevention devices with rational parameters can prevent collapse of the structure; the damage-reduction seismic performance of bridge was influenced by the cable rigidity and primary clearances. The unseating prevention devices will improve the seismic performance and integrality of bridge, but higher requirements have been proposed for the substructure of bridges.

Abstract: Earthquakes are human recognized natural disasters, causing tremendous loss of life and property to human society, so how to strengthen the seismic capacity of the building more effectively is one of the challenges faced by scientists.While the use of a damping device is an effective method. With the rapid economic and social development, the urban transport problem is an extremely serious livelihood problem faced by all countries. To solve urban traffic congestion, in many cities setting up viaducts is a widely used way to ease urban traffic pressure, and elevated expressways are the main bridges among continuous bridges. In order to ensure the safe operation of the urban elevated road system, we must make the correct evaluation of their seismic capacity. This paper focuses on the continuous beam bridge seismic response history analysis of installing viscous dampers and lock-up devices,compared with the general scheme of continuous bridge.

Abstract: The theory deduces the formula of closure jacking force in the closure of mid-span in the continuous rigid bridge, and introduced the computation and accomplishment of jacking force in continuous rigid bridge, taking the example of Anwen Bridge.