テンタゲートの流水方向固有振動モードの上流側水位に対する非依存性

抄録

To assure the complete long-term stability and safe operation of the large number of Tainter gates used worldwide, the dynamic stability of these gate must be assessed for all operating water levels. The effect of the upstream submergence (upstream water level) on the natural vibration mode of the gate must be carefully examined. When the upstream water level changes, the in-water natural vibration characteristics will change due to the water added mass effect. The natural vibration mode of the skinplate, however, is determined as an inherent vibration characteristic of the gate structure, and the water in contact with the skinplate has the effect of only lowering the natural frequency due to the added mass effect. To assure the accuracy of the stability analysis, the assumption of unchanging vibration mode with changes in the upstream water level must be validated. To do so, this paper presents the test results for a 3-dimensional model gates and for a full-scale operational gate to examine the effect of the upstream water level on the natural vibration mode.