Study on prototype observation of fluid induced vibration of sluice pier of a hydropower station

Abstract

[Objective] Turbulent water flow caused by high-speed water flow is easy to cause the problem of induced vibration of hydraulic structures such as sluice pier. When the structural vibration is severe or the structural resonance is caused, it will seriously threaten the operation safety of the project and even cause structural damage. The spillway of a hydropower station was taken as an example to study the vibration characteristics of gate pier under the action of high-speed water flow, analyze the factors affecting the vibration of gate pier, and provide safety guarantee for the safe operation of the project, [Methods] Through the field test, the left and right gates are gradually opened to form a single hole, a double hole joint operation and other conditions to form high-speed water flow, and monitors the vibration of gate pier under each condition were tested. The vibration characteristics of the pier under the action of high speed water flow are summarized. [Results] The monitoring data show that the pier vibration is larger in general when the two gates are opened at the same time, but when the right gate is opened alone, the maximum horizontal vibration peak value is 244. 37 μm and the standard deviation of the maximum displacement level is 60. 89 μm. The maximum ripple pressure root mean square value is 1. 84×9. 8 kPa. [Conclusion] Under the action of high speed water flow, the vibration of gate pier will increase with the increase of gate opening. In the same horizontal direction, the vibration of gate pier will increase gradually along the direction of downstream flow. In the same vertical direction, the vibration effect is more obvious when the pier is closer to the top. The main reason is that the gate is gradually opened, the flow velocity increases, the flow pattern is disturbed, and the pulsating pressure is easy to form, resulting in flow-induced vibration problems,and the end of the pier is less constrained and the vibration is the largest. At the same time, the vibration of the pier is not only affected by the discharge volume of the sluice gate, but also related to the downstream water level, water flow pattern, and the single and porous operation mode of the sluice gate.

Keywords

high-speed flow / the pier / vibration / regular / flow / hydraulic characteristics / influencing factors