2025大坂世博会“蓝色海洋穹顶”丨日本大阪丨坂茂建筑设计

蓝色海洋穹顶（Blue Ocean Dome，简称BOD）是大阪关西世博会2025的重点展馆之一，旨在提升公众对海洋塑料污染问题的关注。展馆并不直接谴责塑料本身，而是鼓励人们反思我们如何使用和管理材料，强调人类在可持续选择中的责任。BOD巧妙融合了传统与现代材料——竹子、纸张和碳纤维增强塑料（CFRP）——探索建筑创新的可能性。

The Blue Ocean Dome (BOD) at the Osaka-Kansai Expo 2025 aims to raise awareness about the issue of marine plastic pollution. Rather than condemning plastic itself, the pavilion encourages reflection on how we use and manage materials, highlighting the responsibility of humans in making sustainable choices. The BOD creatively blends traditional and modern materials—bamboo, paper, and carbon fiber reinforced plastic (CFRP)—to explore innovative architectural possibilities.

▼展馆外观，exterior of the pavilion ©Taiki Fukao

▼展馆鸟瞰，aerial view of the pavilion ©Hiroyuki Hirai

展馆由三个穹顶构成：穹顶A作为入口空间，由层压竹材建成。这一设计回应了日本日益严重的废弃竹林问题，竹子根系浅，不加管理会导致土地不稳定。由于原始竹材不适合直接用于结构用途，设计团队将其加工为薄片状的层压板材，其强度甚至超过木材。这些板材被构造成一个直径19米的穹顶，灵感来自日本传统的竹编斗笠，巧妙地将生态问题转化为建筑解决方案。

▼展馆轴测图，pavilion axonometric ©坂茂建築設計

The pavilion is composed of three domes. Dome A, serving as the entrance, is built from laminated bamboo. This approach addresses the growing problem of abandoned bamboo groves in Japan, which can destabilize land due to their shallow roots. Raw bamboo is difficult to use structurally, so it was processed into thin, laminated boards that are even stronger than wood. These were shaped into a 19-meter dome inspired by traditional Japanese bamboo hats, transforming an environmental concern into a building solution.

▼灵感来自日本传统的竹编斗笠，inspired by traditional Japanese bamboo hats ©Hiroyuki Hirai

穹顶B是中心主结构，直径达42米，主要采用CFRP材料建造。CFRP因其高强度与轻量特性广泛应用于航空航天与汽车工业，其强度为钢的四倍，但重量仅为其五分之一。由于成本高昂，在建筑领域使用较少。然而，该项目位于填海地，为了避免使用对环境影响较大的深基础桩，结构重量必须低于为基础开挖所移除的土壤重量，CFRP因此成为理想材料，既满足重量要求，又保证结构稳定性。

Dome B, the central and largest structure with a diameter of 42 meters, uses CFRP as its primary material. Known for its strength and lightweight properties—four times stronger than steel but only one-fifth the weight—CFRP is usually reserved for industries like aerospace and automotive. Its use in architecture is rare due to its high cost, but it was ideal for this project, in order to minimize foundation weight on the reclaimed land of the Expo site. To avoid the environmental impact of deep foundation piles, the structure needed to weigh less than the soil removed for its foundation. CFRP allowed the dome to meet this requirement while maintaining structural integrity.

▼主要采用CFRP材料建造，uses CFRP as its primary material ©Hiroyuki Hirai

穹顶C同样为19米直径，由100%可回收的纸管构成。纸管以木质球体为节点，组装为三维桁架结构，整体形式令人联想到分子结构，既轻盈又富有表现力。

Dome C, also 19 meters in diameter, is made of paper tubes that are 100% fully recyclable after use. Assembled into a three-dimensional truss structure with wooden spheres as joints, the dome form is reminiscent of molecular structures.

▼组装为三维桁架结构，assembled into a three-dimensional truss structure ©Hiroyuki Hirai

为尽可能减少六个月展期结束后的浪费，BOD整体采用可拆卸、可迁移的设计，搭建于简易钢结构基础之上，模块化程度高，可装入标准运输集装箱。展览结束后，展馆将整体迁移至马尔代夫，并再利用为度假设施，赋予其“第二生命”。

To minimize waste after the six-month Expo, the entire BOD pavilion is designed for easy disassembly and relocation. It rests on a simple steel foundation system and is modular enough to be packed into standard shipping containers. After the Expo ends, the pavilion will be relocated to the Maldives, where it will be repurposed as a resort facility—giving the structure a second life.

▼夜景，night view ©Hiroyuki Hirai

▼平面图，plan ©坂茂建築設計

▼剖面图，section ©坂茂建築設計