Abstract: The prototype dynamic safety monitoring data of the bottom outlet gate of three gorges project (TGP) is analyzed. The monitoring data include gate’s dynamic property and vibrating acceleration,dynamic displacement, dynamic and static stress, fluctuating pressure, and hoisting capacity under designed water level. The prototype monitoring results show that the natural frequencies of the gate are approximate to the test results of hydroelastic model, and the modal shapes of the gate are the same with those in the hydroelastic model. When the gate is in opening or closing condition with small angles, the fluctuating pressure on the bottom of the gate’s downstream face is bigger, and the acceleration at the bottom of the gate is larger, but the corresponding dynamic displacement and dynamic stress are very small. Moreover, the vibration of gate leaf and support arms under small-opening condition is larger than that under large-opening condition, but with no harmful vibration in the whole process. In conclusion, the flow-induced vibration of the gate is safe.

Key words: Three Gorges Project, bottom outlet gate, dynamic monitoring, vibration analysis