STUDY ON THE FACTOR OF HYDRODYNAMIC PRESSURE ON CREST GATE OF CONCRETE GRAVITY DAM AND SEISMIC RESPONSE DURING EARTHQUAKE

Abstract

 Seismic response of crest gate of concrete gravity dam is considered to be greatly affected by hydrodynamic pressure during earthquake. However, hydrodynamic pressure has not been observed, and the generating mechanism of hydrodynamic pressure due to the motion of gate and dam body has not been elucidated so far.

 In this paper, we measured hydrodynamic pressure and acceleration on the gate during earthquake, and obtained unprecedented data. For the measurement, a hydrodynamic pressure gauge and an accelerometer were installed on the gate. Based on these measurement and reproduction analysis, we analyzed about the influence of the hydrodynamic pressure on the gate against the seismic response of the gate. As a result, we elucidated the following three points. The first is that the mechanism of generation of hydrodynamic pressure on the gate is mainly due to gate vibration. The second is, the natural frequency of the gate changes depending on the water depth upstream of the gate. As for the final, the gate vibration coupled with the water storage has a large interaction with the gate pier vibration.