Research On The Horizontal Seismic Behavior Of The Vertical Vibration Damping Spring Structure

Turbo-generator is the core of the power plant. With the rapid development of power construction,the stream turbines with huge power get more used.To improve the operating environment of unit,using spring vibration isolation foundation is a good solution.As Vibration isolation spring separates the plant from the substructure,it is bound to make great influence to the natural vibration characteristics and dynamic response of the whole structure. Model test can reflects the natural vibration characteristics and dynamic response of structure iconically, veritably, directly. Thus test the structure whether meets the specification requirements.This study takes a spring vibration isolated turbine-generator foundation as the research object. Through building a1:8model of spring vibration isolate turbine-generator foundation, this paper studys the seismic performance by model test. The main work is as follows:Design and build a1:8reduced-scale model according the design drawings and the analogous relation.Perform the vibration test with the transient-exciting method which excits and collects response at three-direction.And obtain the natural vibration characteristics of the foundation, which including frequency, mode shape and damping ratio.Analyzing the characteristics of natural frequency and vibration modes,and coming to the conclusion that the natural vibration frequency is visible decreased,and avoided the working frequency and the site predominant periods by using spring vibration isolation.Test the transfer coefficient according to the definition of the force’s transfer coefficient.The vibration isolation efficiency is ideal.Because the test method in this paper without the assumption of rigid bedplate, it is more reasonable than the simplified calculation method assumed single degree of freedom.The paper evaluated the anti-seismic performance of the structure under7degree basic and rare earthquake intensity by pseudo-dynamic test.The displacement, restoring force time-history curve acceleration,crack developing and the interstory drift are obtained.The design of the foundation meets the standard "Code for seismic design of buildings" under the seismic action.This gains the ends of the proposal purpose.