Multi-objective optimisation of U-shaped yard layout in automated container terminals
针对自动化集装箱码头U形堆场布局，建立了以ARMG循环时间、单箱成本和空间利用率为目标的多目标优化模型，通过仿真验证并分析了参数敏感性，为码头规划提供定量设计指导。
The trend towards larger container vessels places increasing pressure on automated container terminals in terms of operational efficiency, space utilisation, and cost control. The U-shaped yard layout addresses mixed-traffic conflicts between External Trucks (ETs) and Intelligent Guided Vehicles (IGVs) by alternating non-U-shaped and U-shaped blocks, yet systematic optimisation of its key layout parameters remains unexplored. This paper presents a multi-objective optimisation model for U-shaped yard layout, incorporating bilateral-cantilever Automated Rail-Mounted Gantry (ARMG) cycle time per container, total cost per TEU, and yard space utilisation as coordinated objectives. Analytical expressions for all three objectives are derived from equipment characteristics, operational features, and site constraints, and validated against large-scale Monte Carlo simulation with relative errors within ±1%. Full weight-space traversal and multi-dimensional sensitivity analyses reveal that cycle time and space utilisation exhibit positive synergy within the U-shaped layout framework, whereas total cost involves trade-offs with both. Key findings are: (1) space constraints significantly influence the effectiveness of cost optimisation strategies; (2) stacking tiers constitute the core capacity-adjustment parameter; and (3) the U-shaped layout demonstrates strong robustness to throughput fluctuations, container flow variations, and diverse terrain conditions. These findings provide quantitative parameter-design guidance and a replicable optimisation framework for automated container terminal planning.