Abstract: Polar heavy icebreaker is the key supporting equipment for polar merchant shipping, rescue support, scientific investigation and resource exploitation. The polar heavy breaker deserves special consideration in the application of high-strength steel and other special materials, the structural safety assessment under ice load and the hull structural layout, due to the high ice load compared with the medium and low ice class polar ships/icebreakers. The previous structural design experience for medium and low ice class polar ships cannot be arbitrarily applied to the polar heavy icebreaker. The structural design and evaluating experience of a PC2 polar heavy icebreaker that was developed by Marine Design & Research Institute of China (MARIC) are summarized. It focuses on the application of high strength steel for the ice belt structure, the application requirements and characteristics of composite steel plate for the ice belt outer plate, the impact of the non-linear evaluation technology on the ice belt scantlings, and the distribution of the ice-induced shear/bending moment and its influence on the structure in non-ice-belt regions, such as the inner platform of the main ship and the side hull of the bridge. It presents the structural design characteristics of the polar heavy icebreaker and the main differences between the polar heavy icebreaker and the medium and low ice class polar ships/icebreakers in terms of the overall structural layout and the design and evaluation of the ice belt structure. With the increase of the ice class, it is believed that the ice load not only affects the outer plate and its attached components in the ice belt region, but also has significant impact on the material selection of the ice belt structure and the overall structural layout and design of the whole ship.

Key words: heavy icebreaker, polar regions, ice strengthening, ice load, ice belt structure

摘要： 极地重型破冰船是极地航路开辟、救援支援、科学考察及资源开发的重点保障装备。与中低冰级极地船型/破冰船相比,由于其高冰载荷作用环境特点,该船型在高强度钢/特种材料应用、冰载荷作用下结构安全评估以及船体结构布置设计等方面有其鲜明特征,需予以重点考虑,不可武断地沿用以往针对中低冰级极地船型的结构设计经验。该文以某型PC2级极地重型破冰船型为例,总结其结构设计/评估经验,重点就冰区构件高强度结构钢应用、冰区外板复合钢板应用需求与特点、非线性评估技术应用对冰区构件尺度影响、冰致剪力/弯矩分布特点及其对主船体内部平台、桥楼侧壁等非冰带区构件设计影响展开讨论,阐明此类船型结构设计特点及其与中低冰级极地船型/破冰船在整体结构布置思路、冰区结构设计评估方面的主要区别。文中认为：随着冰级的升高,冰载荷的影响已不仅仅局限于冰区外板及其附连构件区域,在冰区构件材料选型及整船全局性结构布置、设计等方面也会产生重大影响。

关键词: 重型破冰船, 极地, 冰区加强, 冰载荷, 冰区结构