Research On Static And Dynamic Performance Transfer Theory Of Curved Box Girder Bridge

With the development of traffic and city traffic network, curved bridge which has pretty appearance is applied more and more widely. Because of the complexity of space force, the significant characteristics of curved box girder bridge is the bending moment and torque would appear in the same time and interact when the vertical loads act on curved box girder bridge, which is called bending - torsion coupling effect. Although many experts and scholars have been researching on curved box girder bridge, and have made great progress, but the existing studies of curved box girder bridge and calculation method are not comprehensive enough. The existing analytical theory can not fully take the complex force characteristics of curved box girder bridge into account; the structural analysis computer programs developed by the existing calculation methods make the analysis of large and complex curved box girder bridges possible, but the data input would be heavy workload, and the results can not directly reflect the transfer law of the state vectors of structures. The main purpose of this paper is making use of a more efficient analysis theory and calculation method - the transfer matrix method, to realize the research of the complex space force problems of curved box girder bridges. The main contents of the paper are as follows:1. The existing design theory and calculation method of curved bridge and the progress of curved bridge researched by the domestic and foreign scholars are summed up; the origin and development of the transfer matrix method are traced, and the application field and development prospects of the transfer matrix method are elaborated.2. The solution idea and calculation principle of the transfer matrix method are narrated, and the field transfer matrix and the point transfer matrix of the general plane bending problem of the straight beam are derived.3. Spatial analysis of curved box girder bridge problem is divided into the problems of horizontal and vertical planes, and the state vectors are divided into two categories correspondingly (the state vectors of horizontal plane and the state vectors of vertical plane).4. The discrete model of horizontal plane of curved box girder bridge is established. The deflection differential equation is established according to the static equilibrium differential equations, geometric equations and the physical equations of the horizontal plane, and the field transfer matrix expression is derived by the application of the closed form solution of the deflection differential equation. The point transfer matrix expression is derived by the static equilibrium equations of the nodes of mutations. The boundary conditions of the typical supports are summed up; the general transfer matrix of horizontal plane of curved box girder bridge is established.5. The discrete model of vertical plane of curved box girder bridge is established. The deflection differential equation is established according to the static equilibrium differential equations, geometric equations and the physical equations of the vertical plane. The field transfer matrix expression is derived by the application of the closed form solution of the deflection differential equation, and the point transfer matrix expression is derived by the static equilibrium equations of the nodes of mutations. The boundary conditions of the typical supports are summed up; the general transfer matrix of vertical plane of curved box girder bridge is established.6. The discrete model of the pier of curved box girder bridge is established. The field transfer matrix expression of the two planes is derived, and the general transfer matrix of the pier is established.7. Making use of the concentrated mass method, the dynamic transfer discrete model of curved box girder bridge is established; the point transfer matrix expression of vibration is derived; the general transfer matrix of vibration of curved box girder bridge is established, thereby the natural frequency and mode can be solved. It's given that combining the mode decomposition response spectrum method with the transfer matrix method to analyse the horizontal seismic response of curved box girder bridge. The point transfer matrix expression of the horizontal plane under the earthquake is derived. With the application of the transfer matrix method some calculation examples are computed, and the results prove that the method is correct and efficient.