Monitoring of Elastic Deformations of the Hydraulic Structure Gabcíkovo

The settlement and its calculations and monitoring are among the main factors influencing the structure and operability of hydraulic structures. Our paper focuses on the hydraulic structure Gabcíkovo which consists of the hydropower plant with an installed capacity of 720 MW and two navigation locks to ensure international ship transportation. Conventional geodetic methods of classical or very precise leveling with state-of-the-art measuring instruments are currently used to monitor deformations on navigation locks of hydraulic structure Gabcíkovo. In their subsoil, there are gravelly sediments to a depth of about 400 m. Under the gravel sediments, there are Neogene clays and silts. From the beginning of construction, deformations are measured on all structures using special tachymetric devices to monitor the elastic displacements. The obtained measured values are then processed in time dependences and compared with the limit values. During the current almost 30-year operation of the navigation locks, filling and emptying cycles, loading and unloading of the subsoil can be counted in the tens of thousands. The impact of the long-term operation, but especially the current innovation and modernization of navigation locks, aimed at increasing the safety and intensity of transport brings new knowledge and experiences. During the implementation of required improvement related to this project, the right navigation lock is empty for more than a year. The created technical conditions made it possible to monitor the influence of long-term unloading on the subsoil on the vertical displacements in detail. This unusual load condition is a motivation to present the results of measurements in the presented paper.

Parametric study of direct filling system of medium-head navigation locks

As part of the research focusing on the safety of vessels during the lockage in navigation locks, two different 1D numerical modeling approaches were tested. These approaches are used to determine the force effects on vessels during the direct filling process of the navigation lock. These numerical models were verified using data measured on a physical model. Using the selected 1D model, a parametric study focusing on the impact of the basic parameters of the navigation lock including the lifting velocity of the gates on the maximum hawser forces was performed. The research has shown that with a suitable design of the upper gate, the direct filling system may also be used for medium-head navigation locks with a normal lift of up to 5 m.

WAVE LOADS ON A NAVIGATION LOCK SLIDING GATE: NON-LINEAR EFFECTS

The wave loads on a navigation lock gate provided with an opening in the ballast tank are analyzed using a mathematical model based on the linear wave theory and the numerical integration of the Navier-Stokes Equation. The analysis focuses on the evaluation of the non-linear effect influence on the vertical load on the gate. It is shown that the numerical and analytical models agree on the identification of the value of the wave number at which the maximum value of the dimensionless vertical force on the gate is detected. However the analytical model overestimates the peak value of the vertical load with respect to the CFD simulation. To fill this gap, in this paper an easy to use procedure is developed which allows to correct the results of the analytical model.