Abstract: In recent years, the close connection of the international supply chain and prosperity of maritime trade have led to a sharp increase in cargo throughput in many bulk ports. Meanwhile, as large ships gradually become the mainstream, ports that cannot provide sufficient deep-water berths due to natural conditions are constantly facing complaints from shipping companies. In this context, the reality that most bulk ports in China still rely primarily on shallow-water berths becomes particularly prominent. To alleviate the waiting pressure of large ships and meet service needs for small and medium-sized ships, how to efficiently utilize existing berth resources has become an important issue in port management. To this end, this paper conducts an in-depth study of the optimization of berth allocation considering berth shifting operations. By designing flexible and efficient berth shifting operations, it can not only shorten the waiting time of large ships and reduce port congestion, but also better meet service needs for small and medium-sized ships and achieve balanced utilization of berth resources. This paper first outlines the research background and emphasizes the importance and practical application value of studying berth allocation optimization considering berth shifting operations. Subsequently, it reviews and summarizes existing literature from two aspects: one is the study of berth allocation without considering the impact of berth shifting operations, which mainly focuses on the basic theory of classic berth allocation problems; the other is the study of berth allocation considering the impact of berth shifting operations, which pays more attention to the influence of berth shifting operations on port operation efficiency and service quality. Through combing and evaluating the existing literature, this paper further elaborates on the theoretical value and practical significance of the issue.
This study can be described as follows: it focuses on the temporal and spatial constraints of continuous berths within a single terminal in bulk cargo ports, while considering factors such as the draft depth of arriving vessels and the operational berth shifting requirements for certain ships. It designs an optimal combination scheme for partially arriving vessels involving load-shifting and berth-shifting to reduce the total time spent by all arriving vessels in port. To achieve this, a berth allocation model is constructed with the objective of minimizing the total time spent by all arriving vessels in port. Additionally, an improved genetic algorithm, incorporating variable neighborhood concepts, is designed to solve the model and obtain the optimal berth allocation scheme. In the case study analysis, the effectiveness of this scheme is first validated by being compared with that of existing schemes such as first-come-first-served and those that do not consider berth shifting operations. Secondly, the effectiveness of the proposed algorithm is verified by comparing it with that of the solution process of CPLEX. Finally, two types of sensitivity analysis experiments are conducted to analyze the impact of different proportions of large vessels and different intervals between vessel arrivals on berth allocation, emphasizing the importance of vessel arrival time intervals and considering periods with a higher proportion of large vessels among arriving vessels. The results indicate that, under the premise of limited berth resources, a berth allocation plan that encompasses appropriate combinations of load-shifting, berth-shifting, and operational berth shifting can effectively reduce the waiting time of vessels in port, thereby enhancing customer satisfaction. To further improve berth resource utilization, it is recommended to coordinate vessel schedules with anticipated arrivals from shipping companies to stagger vessel arrivals as much as possible, and to pre-plan large vessel allocation based on the scale and workload of arriving vessels, assigning multiple large vessels arriving in clusters to different terminals. These strategies offer new insights and significant reference value for the formulation of berth allocation plans in bulk cargo ports.

Key words: bulk cargo port, berth shifting, berth allocation, improved genetic algorithm

摘要： 为提高散货港口的服务水平,实现泊位资源的充分利用,研究了考虑移泊作业的泊位分配优化问题。针对一单港池连续泊位的散货码头,考虑船舶吃水深度等现实约束,重点为一些船舶设计了减载移泊和让位移泊的泊位优化方案,兼顾作业移泊的现实需求,建立了以所有船舶在港时间最小为优化目标的泊位分配模型,并设计融入了变邻域思想的改进遗传算法进行求解,最终得出最佳的泊位分配方案。通过与CPLEX求解过程进行比较,验证了本文算法的有效性;设计了敏感性分析实验,分析了不同的大型船舶占比和不同的船舶进港时间间隔给泊位分配带来的影响,可为散货港口实际泊位分配作业提供决策支持。论文在已有研究的基础上增加考虑了让位移泊和作业移泊两种作业,研究成果有助于降低船舶在港等待的时间,提高港口泊位资源的利用率,为散货港口泊位分配计划的制定提供一个新的思路和一定的借鉴意义。

关键词: 散货港口, 移泊, 泊位分配, 改进遗传算法