Structural parameters analysis and optimization design study of double-pier linkage-type anticollision device

The double-pier linkage-type anticollision device (DPLT-AD) is a novel protective device for double-bridge systems, allowing two piers to jointly resist ship collisions, thereby enhancing each pier's collision resistance. To distribute the ship collision force more evenly to the two piers, this paper conducts an optimization study on the DPLT-AD. Firstly, a novel simplified finite element (FE) model of the viscoelastic energy-absorption ring (VEAR, the crucial force-transmitting component in the DPLT-AD) was proposed and proven to effectively capture the actual mechanical behavior of the VEAR. The modeling approach in this paper was validated through full-scale ship collision tests. Subsequently, the effects of the VEAR's quantity and stiffness and the outer steel box's plate thickness on the force transmission performance of DPLT-AD were discussed. Results show that the synergistic force effect between the double piers was highly sensitive to the quantity and stiffness of the VEARs within the triangular area and the plate thickness of the entire outer steel box. Based on parameters analysis, a multi-objective optimization design method for the DPLT-AD was proposed using the BBD response surface method and the NSGA-II algorithm. After optimizing the DPLT-AD, the synergistic force effect between the double piers under high-velocity collisions from large-tonnage ships was significantly enhanced, and the peak ship collision force was also reduced, greatly improving the safety of each bridge. This study can provide a scientific and rational solution to address the issue of large-tonnage ships colliding with double-bridge systems. •DPLT-AD enables two piers to jointly resist the ship collision.•A simplified modeling approach of the VEAR was proposed and validated.•Structural parameters analysis of the DPLT-AD was conducted.•A multi-objective optimization design method for the DPLT-AD was proposed.