The vertical vibration of the head cover has exceeded the national standard since the Baishi hydro-power unit was put into operation

and the problem is dealt with by the method of strengthening the head cover in the power plant. The power plant adopted the method of combining simulation and field measurement to build the head cover model accurately

to successfully predict the natural frequency of the head cover after reinforcement

and avoid the resonance risk caused by the close proximity between the natural frequency of the head cover and the water pressure pulsation in the flow passage

which ensures the successful implementation of the head cover reinforcement scheme. The experimental results after the reinforcement showed that the measured natural frequency was close to the predicted one by simulation

and the vertical vibration of the head cover was obviously improved. Under the test water head

the vertical vibration of the head cover meeted the requirements of the national standard within full load section.