Research On Dynamic Characteristics And Anti-vibration Design Of Underground Powerhouse Of Hydropower Stations

The vibration units are major issues involving safe and stable operation of hydropower units. With the completion of many hydropower stations and large capacity pumped-storage Project, the vibration of powerhouses induced by units vibration and pulsating water pressure has became more intense. The vibration of units and powerhouses can have some destructive effects on the structure, affect the safe and stable operation of electrical equipments and worsen working conditions by generating noise. Therefore, the rigidity of the concrete supporting structure around the unit and the vibration of units became two very important problems for the dynamic design process, which have been drawn more and more attention by designers and operators. Base on this, the dynamic characteristics of the hydropower house have been analysed in this paper using the finite element method and related theories of structural dynamics. The main content includes several aspects.First, a finite element model was built up. The applicability of the MPC method in dealing with the uncoordinated connection among elements that have different nodal DOF was expounded theoretically. And its correctness was proved by calculated results. Then the simulation method of boundary constraint of combination between the house and surrounding rock was studied, which laid the foundation of dynamic analysis of the powerhouse.Second, research on anti-vibration design of the hydropower house. Some structural measures were summed up and analyzed, like the contrast between thick plate structure and slab and girder structure, changing the size of columns and the contrast between solid wall and columns. Based on the research works, some proposals about the size and shape of the structure have been put forward for prevention of resonance and control of structural vibration, which can be used for anti-vibration design of powerhouse structure.At last, Study on the amplitude of vibration of generator pier. By using the method recommended in relevant specification and the finite element method, the amplitude of vibration of generator pier was calculated with different models. Through analyzing, the conclusions were put forward, which can be used for dynamic design of generator pier.Based on the above research, effective and feasible method for anti-vibration design of hydropower house have been put forward, which can lay some useful reference for dynamic design of large-scale underground powerhouse of hydropower stations.