Vibration of Bottom Outlet Slide Gate in Dobczyce Dam in-situ Measurements and Numerical Analysis

Dams with accompanying reservoirs (retention, drinking water) are often objects of strategic importance. Among various dynamic loads affecting dams, vibrations induced by the flow of water through the bottom slide gate can be mentioned. Determining the impact of these vibrations on the dam safety - especially during emergency water discharge during flood surge is extremely important.

The paper presents results of “in situ” vibration measurements of two quite important structure elements necessary to faultless operation of the dam: the selected bottom outlet slide gate operating in the normal conditions (closure of bottom slide gate) and the control room building. In order to determine dynamic characteristics of the chosen bottom slide gate and control room building the controlled dynamic excitation was used, including modal hammer, lift movement as well as synchronized movement of the people located on the top floor. Carried out measurements and its analysis allows authors to determine the dynamic characteristics of the investigated objects necessary for further dynamic calculations.

Prepared numerical models were used to determine the impact of vibrations on the control room building itself as well as on people staying inside. Additionally influence of the lift height of the bottom slide gate onto level of induced vibrations was numerically analyzed. This calculations allowed to determine - in a simulation way - level of vibrations as a function of the lift height of the bottom slide gate, which helped establish the "safe" work range. Proceeded analyzes allowed to formulate conclusions and recommendations regarding the impact of vibrations on the examined objects, on people staying inside and safe use of the object itself.