Determination of the optimal modes of filling and emptying the chamber of the navigational lock of a low-pressure hydroelectric complex

The construction of the low-pressure Nizhny Novgorod hydroelectric complex covered by the Strategy for the Development of Inland Water Transport of the Russian Federation for the period up to 2030 envisages a ship lock as part of the hydroelectric system to ensure ships passage. One of the options under consideration is a ship lock with a head power system, which uses short bypass water-circulating culvert for filling and emptying the chamber. At the same time, an important task is to select the optimal modes ensuring movement of the gates of the filling and emptying systems, in which the normative values of the hydrodynamic forces influencing the vessel in the chamber during the lock process would not be exceeded. The article describes the experience of performing laboratory hydraulic studies of the ship lock model and presents the results of determining the optimal modes of locks movement in the ship lock filling and emptying systems. The studies were carried out on a model located in the hydrotechnical laboratory named after Professor V.E. Timonov of the State University of Maritime and River Fleet named after Admiral S.O. Makarov. The article describes the experience of performing laboratory hydraulic studies of the ship lock model and presents the results of determining the optimal modes of gates movement in the ship lock filling and emptying systems. The studies were carried out on a model located in the hydrotechnical laboratory named after Professor V.E. Timonov of the State University of Maritime and River Fleet named after Admiral S.O. Makarov. The studies included three series of measurements taken at different speeds of gates movement. The speeds were assigned based on the following idea: the maximum hydrodynamic forces of one of the series were close to the permissible values, and of the other two – 30–50 % smaller and larger, respectively. The experimental results determined the optimal operating modes of the systems for filling and emptying the lock chamber. It is recommended to select of the optimal modes of gates movement in full-scale conditions on the newly built ship locks immediately after their construction.

Structural Optimization Design of Ship Lock Heads on Soft Soil considering Time-Varying Effects of the Structure and Foundation

Over time, the uneven settlements of the structure and foundation are prominent in constructing ship lock heads on soft soil. These deformations endanger the safety of ship lock heads during construction. This research aimed to establish the ship lock head’s structural optimization procedure on soft soil, considering the time-varying effects of the structure and foundation. By comprehensively considering the linear viscoelastic creep of concrete and the elastoplastic consolidation characteristic of soft soil, a perfect time-dependent analysis method for the lock head on soft soil was proposed. Furthermore, a hybrid particle swarm optimization, enhanced whale optimization, and differential evolution (PSO-EWOA-DE) algorithm was proposed to optimize thirty-four design variables of a lock head. With the minimal volume of the lock head as the optimization objective, the finite element model was established. In the optimization process, three types of constraints were evaluated. The result showed that the optimized design could reduce 10.45% of structure volume. Through comparing and analysing the maximum principle stresses and vertical displacements of the lock head before and after optimization, some conclusions were drawn. The optimization procedure proposed in this paper provides a new perspective for the structural optimization of hydraulic structures on soft soil.