Papers by Keyword: Curved Bridge

Abstract: The existing methods of curve beam bridge is the finite element method, the modeling and analysis of complex, heavy workload, not suitable for the proposed design method of regularity. According to the character of curved bridge, the bridge superstructure and piers is simplified as packing quality model that have two levels of degrees of freedom and a surrounding mass center shaft torsion degree of freedom, then the analysis model of double mass simplified 6 degrees of freedom is established, studying the dynamic characteristics and the structure vibration behavior through the dynamics equation of curved bridges. Example show that,the results of double mass model with the traditional of finite element model is consistent, double mass model has simple calculation method and can consider the influence of sensitive factors, with the help of programming is more suitable for the proposed design method of regularity. At last, Application MATLAB programming discussed the critical angle of the curved bridges under multi-dimensional earthquake based on double mass model, after change the curve bridge related parameters only one operation can achieve the most disadvantaged angle.

Abstract: In the condition of the same span, to change the continuous curved bridge's curvature radius and under the dead load and moving load to compare how the internal force changes in different curvature radius. The finite element model is established to simulate the actual structure by Midas Civil. Results in a continuous curved bridge which main span of less than 60m, under the dead load, bending moment (-y) is unlikely to change, reinforced by a straight bridge can meet the requirements; under the moving loads, the curvature radius of the bending moment (-y) has little influence, should focus on increase in torque and bending moment (-z).

Abstract: In the modern urban bridge projects,especially the urban interchange projects and the urban viaduct projects,the long-span curved bridge with the small radius is often inevitably used,considering the transportation under bridges,pipelines and aesthetic factors.This kind of long-span curved bridge with small radius was adopted on the south of Second Ring Road in Chendu of the project of "Two Expressways,Two Extended Roads,Two Ring Roads".The influence,which the change of the parameters on the structure had,was analyzed by using the finite element software of Midas Civil 2010.Then,the parameter which had greatest impact on the inner force of the structure was found.The girder depth is the key parameter in design.

Abstract: The curved bridges suffered severe damages or even collapsed during 2008 Wenchuan Earthquake. A field survey of seismic performance of RC curved bridges was examined. Damage patterns and the probable causes of RC curved bridges including Baihua bridge and ramp bridge of Huilan interchange are presented and analyzed in this paper. The main failure was pure shear failure or shear-flexural failure of the pier columns. Bearings and expansion joints damage were another common failure pattern. Lesson learned from the damage of RC curved bridges in this earthquake, the recommendations on the seismic design of RC curved bridges are presented involving ductility of bridge columns, design of curved bridges, design of bearings and devices preventing girders falling down. Suggestions for the future seismic design and retrofitting of RC curved bridges are also presented in moderate to severe earthquake area.

Abstract: The calculations of plan truss and beam-girder method on straight bridge were analyzed, which determined right beam-girder method calculation model of the box-girder bridge. Based on this model, the different radius continuous curved box-girder bridges were simulated by finite element, and then the internal forces of the bridge were obtained. The calculations of inner beam and outer beam show the change rule of internal force and bridge radius. The reasonable calculation methods of continuous curved box girder bridges are obtained, which can offer help to the bridge designers.

Abstract: An ANSYS-based spatial approach of analysis is proposed for the bridge-vehicle interaction to investigate the dynamic responses of a curved concrete box girder bridge and vehicles. The governing equations of a vehicle model with twelve-degrees-of-freedom (12DOF) are derived from the energy method using the Lagrange equation of motion. Both the bridge and the vehicle system are discretized adopting element type BEAM44, MASS21 and COMBIN14 in the ANSYS program. The interaction forces between the vehicle and bridge are deduced considering the road surface roughness and its velocity term based on the compatibility conditions of the contact points, and detailed formula are presented. The separate iterative algorithm is developed to solve the vehicle-bridge interaction problem. A three-axle cargo truck and a dual-cell box girder curved overpass bridge are chosen for both numerical and field test analysis. The dynamic properties and the dynamic responses of the bridge are both obtained from the numerical and experiment way, and the results agree well with each other by comparison. Its indicated that the procedures presented in this paper can be taken for the further vibration analysis study of curved concrete box girder bridges.

Abstract: Wheel diameter difference has great impact on the operation performance of vehicles which are traveling on the curved bridge. A simulation analysis model was built to analyze the influence of wheel diameter difference on safety and stationarity of vehicles on the curved bridge. The results demonstrate that along with the increase of wheel diameter difference, the security of vehicles on the curved bridge decreases and the vehicles run unsteadily. So the wheel diameter difference should be diminished as much as possible, especially strictly controlling the wheel diameter difference of high-speed vehicles.

Abstract: Two curved bridges with typical line shapes: C shaped curved bridge and S shaped curved bridge were selected to study the influence of line shapes on the dynamic parameters of the curved bridge. Spatial finite element analysis models were established and the seismic responses of the two bridges in different earthquake input directions were studied by the elastic dynamic time history method. Results show that: except for the first natural period, the rest natural periods of the two bridges are basically the same; the earthquake resistant capability of the C shaped curved bridge is worse than that of the S shaped curved bridge; under earthquake, the control input direction is Y-direction, and the control internal force is the axial force-Fx, shear Fy, and the moment Mz; relative to the horizontal seismic inputs, the internal force produced by the vertical seismic input is very small, and it can be resisted by structural measures in seismic design.

Abstract: Horizontally curved box girder bridges inherently exhibit complex torsional and distortional behavior as well as bending due to the initial curvature. As to the horizontal curved composite box-girder bridges with corrugated webs, diaphragms were arranged reasonably to reduce torsional and distortion effect for safety and stability due to the coupling of bending and torsion effect for initial curvature and reduced bending stiffness in horizontal direction for corrugated steel webs. Finite element models for a 3-spans continuous horizontal curved composite box girder bridges with corrugated webs were established. Comparing the ratio of warping normal stress to bending normal stress, the influence of the number and spacing for diaphragms on distortion control for curved bridges is investigated. Extensive parametric studies (including central angle, the aspect ratio of the box section, the spacing of the intermediate diaphragms)are performed and the design suggestions for the maximum spacing of the intermediate diaphragms are presented.

Abstract: A four span curved HcontinuousH HboxH-girder bridge is used as an engineering example to investigate the effect of radius of curvature on the seismic response of curved bridge. Numerical models with different radii of curvature are created using the finite element analysis program Midas/Civil. The calculation results obtained from response spectrum method show that radius of curvature is an important parameter to curved bridge. When the radius of curvature is large enough, the relationship between seismic response of main girder and radius is approximately linearity, while nonlinear variation is obtained when the radius is not too large. Finally, conclusions are made that seismic design of Hstraight bridgeH unHfoldHed from curved bridge which radius of curvature is specified could Hsatisfy the engineering Hrequirement.