Hydrodynamic Forces on the Valves of the Transfer System of the Third Set of Locks of the Panama Canal

The expansion of the Panama Canal system of locks through the construction of a third set allows the passage of larger vessels by the construction of three lock chambers on each of the extreme locations, one on the Pacific Ocean and the other one on the Atlantic Ocean. The transfer of the volumes of water required to equalize water levels between successive chambers is carried out by means of four gates, arranged in lateral conduits, with a maximum flow of 216 m³/s and a mean flow velocity of 8 m/s per conduit. The optimization of the integral system consists in the reduction of the total time for the passage of a vessel, the hydrodynamic conditions for the transfer system, the gates and those related to the stability of the vessels must be guaranteed. With the purpose of evaluating the hydrodynamic actions on these gates, whose total number rises to 64 in the whole complex, and to contrast the values ​​obtained with those determined by the designers, INA proceeded to the construction of a physical model at a length scale 1:16, where the approach and exit boundary conditions of the gates chamber were represented, including the volumetric representation of the chambers upstream and downstream. The execution of tests in static conditions (fixed gate) and dynamic conditions (with gate movement) allowed to evaluate the hydrodynamic forces on the gates taking into account several scenarios of water elevation differences between upstream and downstream sides of the gates, arrangement and quantity of operational gates, the opening-closing sequence of the gates, the maximum flows and / or the transfer hydrographs that resulted from the evaluation and optimization of the locks system previously carried out by the project group. The evaluation has shown the presence of downpull forces up to 80% gate openings, with up-lift forces for upper openings. The experimental results have a similar tendency to the determination of the designer, although with maximum values ​​lower than those evaluated by the designer, which indicates that the construction of these gates with the conditions provided in the design bring safety conditions required for the operation of the lock system.