Analysis of ship impact on lock gates - Seine-Escaut Est waterway

This paper presents a ship impact analysis on lock gates. The case study is the downstream lock gates of the one of the four new locks planned within the framework of the “Seine-Escaut Est (SEE)” project in the Walloon Region of Belgium. The design and optimization process of the gate was realized with the LBR5 lock gate optimization software considering the cost and weight aspects of the structure. This method led to an optimized solution of the lock gate on which further studies were concentrated. After a brief overview of the state of art of ship impact analysis on lock gates, it was decided to perform a quasi-static analysis by finite elements. The non linear finite elements software FINELG was used to conduct a non linear numerical analysis of the effect of a boat impact on the gate. Several analyses were performed that highlighted the influence of the stiffener dimensions and the influence of the impact zone on the gate structural behavior submitted to impact. Finally, two different behaviors have been distinguished, a ductile one and a fragile one. The results showed the importance of the development of a global plastic mechanism, thanks to a ductile behavior, with the purpose of dissipating a large amount of energy.