The Research Of A Long-Span Reinforced Concrete Arch Bridge With TMD

In the mountains of southwest China, the long-span arch bridge, which has good mechanical performance and great crossover capability, is widely used.With the development and further research of long-span arch bridge, the vibration control of long-span arch bridge is becoming increasingly important, which has been treated as new research topics in engineering applications. Many research achievements mainly concentrated on the strength of the material and deformation of the arch in resist of wind vibration and earthquake. Therefore, it is necessary to study the seismic control of arch bridge.Tuned mass damper system consist of a spring, a damper and a mass. TMD owns specific operational principle and convenient later maintenance besides low fabricating cost, has been widely used. Appling TMD to the arch seismic response, this research is a good guidance for studying the control mechanism of TMD. This paper is based on Ye Lang river arch bridge(the length of calculation span is 370m), the concrete research content is as follows:(1) The arch bridge is successfully is modeled to finite element software and then eigenvalues were calculated. The controlled modal is analyzed in all vibration modes, the theory of TMD and its design parameters are introduced.(2) With the aim to control the controlled modal, laying position and the scope of mass change besides theoretical spring stiffness are determined. Through Ye Lang river arch bridge time history analysis is researched by three different waves, during the research, optimal spring stiffness of different mass are obtained.(3) The effect that the mass of TMD may impact a departure from the catenary line and the static stress of cross-section rods is calculated, it proves that the displacement of the apex of arch changes little, though the internal force of local members increase, the ranged amplitude is very limited. All these do not affect the safety of the structure(4) Through the response spectrum analysis for the lateral seismic response during different TMD, the type of TMD belongs to mode control. These parameters of TMD which are calculated in time history analysis affect the seismic response of some modes of vibration in response spectrum analysis.(5) The research contains conclusion that the TMD which are used to lateral vibration may affect the seismic response of the bridge's longitudinal and vertical vibration.In conclusion, the TMD placed on the top of main arch ring for reducing the earthquake response is reasonable and feasible.