Analysis Of The Traveling Wave Effect And Vibration Reducing Of Long-span Concrete-filled Steel Tubular Arch Bridges

Earthquake poses serious threat to the survival and development of mankind. Ever since the emergence of human beings, people have been struggling to resist earthquakes. With the development of science and technology and the improvement of people's living standards, the capacity to prevent and withstand earthquake disaster is constantly improving. Structural damping technology as an effective method to resist earthquakes (strong winds) has been developed and applied, and become a mature technology.With the development of national economy, the long-span bridges have gone through rapid development in our country. It is well known that the long-span bridges are usually the hinge of transportation, the building of which require large investment and which tend to play a pivotal role in national economy. Besides, once destroyed, huge economic loss will be caused, and serious effects on earthquake relief work and rehabilitation of the disaster area exerted. Thus it is of great importance both for society and economy to adopt effective seismic fortification measures to ensure the safety of the structure of long-span concrete-filled steel tubular arch bridges in earthquake. The installation of viscous dampers in the long-span bridges won't increase the stiffness of the structure, and the grider can deform freely due to temperature fluctuation. And in the meantime, as viscous dampers can consume the vibration energy produced by earthquake and wind, the vibration responses of the long-span bridge can then be effectively controlled. Therefore, the method can be an ideal vibration mitigation technique for long-span bridge. The Fujian Putian Kuokou Bridge is a concrete-filled steel tubular arch bridge, the main span of which is 99 meter long. The earthquake intensity of the site of this bridge is VII. This thesis hereby focuses on the analysis of response spectrum and traveling wave effectiveness in different phases, and vibration reducing control research of the bridge.The thesis aims to do research on the vibration reducing control behavior of CFST arch bridge. And with its basic dynamic performance and the 3D-spatial elastic-plastic time history reactions as the center, main tasks undertaken by this article are as follows.(1) With Fujian Putian Kuokou Bridge as the example, a dynamic analysis model of the bridge is established by employing the finite element program ansys. And dynamic performance analysis and earthquake response analysis of the traveling wave effectiveness in different phase are then conducted.(2) According to the features of Fujian Putian Kuokou Bridge, the arrangement plan of viscous dampers, the damping device, is defined, and by comparing the seismic responses of the bridge before and after installing the damping device, analysis of the damping effects of the viscous damper on long span concrete-filled steel tubular arch bridge is performed.(3)Analysis of the impacts made by parameters of the viscous damper and the location of it on damping effect is undertaken to provide reference for the damping design of long-span concrete-filled steel tubular arch bridge.