Study on vibration of underground powerhouse of a large-scale hydropower station

Inhalt:
Hydropower is an important clean energy with the largest capacity in China. Due to the influence of various vibration source loads, the vibration of the powerhouse is one of the important problems affecting the operation of the hydropower station. In this paper, the comprehensive study on vibration problems was conducted based on a large-scale underground powerhouse structure. Firstly, the vibration test points were arranged in the underground powerhouse, then the vibration intensity variation with unit load was obtained from large amount of vibration displacement data. In the other hand, the dominant frequency distribution was analyzed to explore the characteristics of the vibration source, and also the component proportions were derived based on wavelet decomposition and reconstruction to quantify the degree of contribution of different vibration source for the vibration of the powerhouse structure. The field test results showed that: (1) The vibration of the tested powerhouse structure is generally in a relatively safe state. The vibration in vertical direction is significantly greater than the vibration in horizontal direction. (2) The vibration intensity gradually decreases with the unit load increasing. (3) The tail water pulsation is the main sources of the vibration. which has a significant contribution more than 90% to the vertical vibration. This study can provide guidance for further research on the vibration of underground powerhouse structure of hydropower station.