Analysis Of Vehicle-bridge Coupling Vibration On Highway Curved Continuous Beam Bridge

With the rapid development of China’s transportation infrastructure in recentyears, curved continuous beam bridges are widely used in highway interchange acrossthe highway, approach bridges of long span bridges and urban overpass bridges, andmost of which are prestressed concrete curved bridges. Though great progress hasbeen made in static analysis theory of concrete curved bridges in the several decades,the theoretical and experimental research on the dynamic performances of curve beambridges gains less development. There is no specific criteria in China available for thedynamic design on concrete curve bridges. And most assessment of impact factor ofcurved bridge under moving vehicles loads adopts the methods of assessing straightbeam bridges. Thus, the studies of dynamic performance of concrete curve bridgeshave significant effect on the perfection of design theories. This thesis focuses on thedynamic simulation model and its dynamic responses due to vehicles loads for anactual curved box girder bridge. Engineering test procedure is compared to verify thereliability of the procedure developed in this paper. The main contents are as follows:(1) This thesis gives a brief review on the theoretical research, experimentalstudy on vehicle-bridge coupled vibrations,especially on vehicle-bridge coupledvibrations of curve beam bridges at home and abroad.. Based the review, this thesismaps out the main contents and research route.(2) This thesis introduces the basic theory of finite element analysis of structuraldynamics of the curved girder bridges. Based on3D beam element, it groups overallbridge stiffness matrix and deduces unit mass matrix, stiffness matrix, dampingmatrix, load array, and the equation of unit motion; the structural dynamic equationsare solved by the Newmark-β method. The bridge structural dynamic responseanalysis program is developed based on MATLAB platform.(3) Based on the assumptions of rigid body dynamics and vehicle dynamics, itdiscretes the vehicle into spring unit and mass unit and deduces the motive equationof three-dimensional overall vehicle model. It applies the method of Inverse DiscreteFourier Transform to simulate road roughness, and according to national standardsGB/T7031-86, the road surface roughness for grade A,B,C are generated, which laysfoundation for the subsequent research of curve vehicle-bridge coupled vibrations. (4) According to the basic theory of the vehicle-bridge coupled vibration, theintegral dynamic equation was solved by Newmark-β method. Based on MATLAB acurved girder bridge-vehicles coupling vibrations analysis program was developed.The calculated results were compared with ANSYS software. The field tests of abridge under moving vehicle loads were conducted to verify the reliability of theprogram developed in this paper.(5) The influence of different parameters to the dynamic response of bridge isanalyzed,such as road surface roughness, the radius of curvature, vehicle speeds,structural damping ratio, the number of bridge spans, and the restrained condition.