A Study Of Vibration Reduction Design Of Main Building And Vibration Transmission Route Of Main And Auxiliary Building In Hydropower Station

With the planning,construction and rapid development of our country’s hydropower industry,there are more and more power plant has been built,hydropower plant as an important buildings in hydropower station hub,the importance and security is increasingly prominent.Hydropower unit capacity,the size is bigger and plus fast running speed,so the vibration is inevitable.On the one hand the unit vibrations will cause the vibration of the support structure,on the other hand it will damage the staff’s physical and mental health,and cause the vibration of powerhouse structure,in this way it will endanger the safety of the hydropower station.This needs to take certain measures to reduce the vibration of powerhouse structure to make the unit running safely.For pumped storage power station,due to its high water head,large capacity,and its vibration intensity far beyond the conventional hydropower station can cause different degree to the adjacent deputy factory of vibration,in order to control the vibration of the workshop,we need to do carefully research of vibration transfer way to find a suitable and feasible solution to reduce the vibration of powerhouse structure.According to the above problem,this paper combined with the structure of a underground pumped storage plant,using the finite element method for structure vibration research and main factory building vibration transfer way,specific research work is as follows:(1)Build finite element model of the underground powerhouse structure,to research structure of vibration characteristics and dynamic response under different boundary conditions,and to seek a reasonable calculation of boundary conditions.On the basis of it,and then calculate the structural damping ratio and the added mass of workshop numerical model,the influence of the dynamic design and vibration isolation for the workshop provides reference and basis of vibration reduction.(2)The main factory building of generator floor laying viscoelastic damping materials,and build the finite element model of free damping plate structure and constrained damping plate structure to study the impact of the thickness of damping layer,elastic modulus and damping ratio on dynamic response.Exploring the vibration reduction method is reasonable and efficient.The results show that,laying the viscoelastic damping materials on floor can reduce the natural frequency of vibration structure,it may avoid the resonance region very well;the modal damping ratio of composite structure are greatly influenced by the thickness of damping layer and damping factor,increasing linearly with the increase of thickness of damping layer or damping factor;The damping plate structure can reduce the vibration response of a floor,and the constrained damping board structure have a good vibration damping on low frequency and high frequency load,The modal damping ratio increases more than 90% than the free damping board structure,On the vibration reduction effect is much better than the free damping plate,the damping effect is much better than the free damping plate mechanism.(3)Building a coupled finite element model of the main machine hall and the auxiliary plant,and the self-vibration features of the auxiliary powerhouse was analyzed and its resonance feature was checked.By changing the mechanical parameters of the filer that between the main powerhouse and the assistant powerhouse,and based on the vibration response of a floor to discuss the vibrational travel and behavior.The results show that,the vibration of auxiliary powerhouse most depend on the surrounding rock;when the elastic modulus larger structure seam filler material,under the effect of flow pulsation pressure in high frequency,the vibration of auxiliary powerhouse that close to load position mainly through the joint filler for transfer.