Research On Multi-dimensional Seismic Response And Damping Control Based On Viscous Damper Of High-rise Chimney

As an integral part of the high-rise building in the thermal power plants, chimney plays an important role for the normal operation of electric power system. It is similar to a cantilever structure, there is almost no redundant bar in the internal structure and the seismic defense is relatively small. In the earthquake, once a plastic hinge appear in the section of chimney structure,which should be bound to cause serious damage, and may cause heavy losses. However, people usually only consider the horizontal earthquake function and the vertical earthquake ground motion, in the seismic design of high-rise chimney calculation,while ignoring the effect of swinging ground motion. on the structure, In fact, the influence on the structure of swing motion can't be ignored in the vicinity of the source. Therefore, in order to ensure the reliability of the structure, response analysis of the high-rise chimney structure under multi-dimensional seismic and then taking corresponding measures of damping is particularly necessary.In this paper, the high-rise chimney of a power plant in Sichuan as the research object, the high-rise chimney structure was simulated by finite element analysis under multi-dimensional earthquake, and according to the characteristics of suspension structure in steel tube chimney, the energy dissipation method of taking viscous dampers between the steel tube and stop shaking platform was proposed. The main content includes the following:1, Dynamic time history analysis under horizontal earthquake of El Centro wave, Taft wave and artificial wave and Response spectrum analysis were conducted on the finite element model of high-rise chimney structure which was established by using the professional finite element software SAP2000. Analysis of the seismic performance of the high-rise chimney was conducted through the response of the displacement, internal force and acceleration.2, Dynamic time history analysis for high-rise chimney modeling under multidimensional seismic were conducted by using the professional finite element software SAP2000, The results of the high-rise chimney dynamic response of structure were analyzed comparatively under four kinds of condition, which were under horizontal earthquake action, tilt ground motion,coupled horizontal and tilt ground motion and coupled horizontal,tilt ground motion and vertical earthquake ground motion. The tilt ground motion response of the high-rise chimney structure had been discussed emphatically.3, In consideration of features of the Chimney with suspensory inner steel cylinder, viscous damper was proposed to be set at the guide points of chimney to achieve the purpose of energy dissipation and seismic mitigation. By using finite element software SAP2000, two models of chimney structures, with and without viscous damper, were established to perform the analyses of time history under frequent and infrequent seismic actions, and seismic response spectrum. The response of displacement, shear force and acceleration of chimney structure under various conditions were compared, Analysis of the effect of the viscous dampers was conducted.