正在建设中的卢姆神庙的鸟瞰照,展示了由竹元素编织的网络
Aerial perspective of the Luum Temple under construction, revealing the network of bamboo elements. Image Courtesy of CO-LAB design office
探索竹子的韧性极限:一个精彩的结构工程案例研究
Pushing Boundaries with Bamboo: A Structural Engineering Case Study
由专筑网刘婧熹,小R编译
在一个正面临环境挑战的世界中,具有前瞻性的建筑师和工程师越来越倾向于采用可持续的解决方案。尽管钢铁和混凝土长期以来在建筑行业占据主导地位,但竹子现在正成为备受关注的替代材料。凭借其韧性、灵活性和环保性的独特组合,竹子迅速成为那些渴望推动可持续建筑界限的人们的首选材料。
在可持续设计领域进入转型时刻的重要一环是及时推出的《竹结构》电子书系列,本文以此为基础。作为该领域的基准,该系列的第一卷专注于卢姆神庙背后的结构设计过程,这是一堂关于竹子工程的大师课程。这本指南不仅仅是一本理论性的著作,更是一本充满了实际见解、前沿研究和实用专业知识的全面手册。
竹子作为结构材料的使用并非新现象,它有着悠久的历史,可以追溯到几千年前。尽管具有古老的根源,但在现代建筑行业过度专注于矿物基材料的同时,这种传统知识往往被低估。然而,如今竹子正在全球范围内经历复兴,展现出古老智慧与现代工程的和谐融合。这种融合不仅为可持续建筑提供了新的途径,而且感觉像是建筑行业期待已久、不可避免的演进。
卢姆神庙:可持续设计的标志
卢姆神庙坐落在墨西哥图伦郁郁葱葱的风景中,它不仅仅是一座引人注目的建筑奇迹,更是传统智慧与现代工程相结合的先锋典范。该结构设计能够抵御每小时250公里的飓风风力和巨大的地震力量,体现了当我们利用竹子作为结构材料所带来的引人注目的可能性。
In a world grappling with environmental challenges, forward-thinking architects and engineers are increasingly leaning towards more sustainable solutions. While steel and concrete have long dominated the construction industry, bamboo is now stepping into the limelight as a compelling alternative. Thanks to its potent mix of strength, flexibility, and eco-friendliness, bamboo is fast becoming the go-to material for those keen on pushing the boundaries of sustainable architecture.
Bridging this transformative moment in sustainable design is the timely arrival of the "Bamboo Structures" eBook series, which this article is based on. Acting as a touchstone in the field, the first volume focuses on the structural design process behind the Luum Temple—a masterclass in bamboo engineering. The guide serves as more than just a theoretical text; it is a comprehensive manual teeming with real-world insights, cutting-edge research, and practical expertise.
The use of bamboo as a structural material is far from a new phenomenon; it has a rich history that stretches back thousands of years. Despite its ancient roots, much of this traditional knowledge has been underestimated as the modern construction sector became overly focused on mineral-based materials. Today, however, bamboo is experiencing a global resurgence, bringing to light a harmonious blend of ancient wisdom with modern engineering. This fusion not only offers new avenues for sustainable architecture but also feels like a long-awaited, inevitable evolution of the construction industry.
The Luum Temple: An Icon of Sustainable Design
Nestled in the lush landscapes of Tulum, Mexico, the Luum Temple is more than just an eye-catching architectural marvel; it's a pioneering example of what happens when traditional wisdom meets modern engineering. Designed to stand against 250 km/h hurricane winds and significant seismic forces, this structure embodies the compelling possibilities that arise when we harness bamboo’s unique properties as a structural material.
Luum Temple卢姆神庙 / CO-LAB设计事务所
Luum Temple / CO-LAB Design Office. Image © César Béjar
这一建筑策划由CO-LAB设计办公室构思,由Architectura Mixta实现,并受到传奇建筑师Felix Candela标志性作品的启发。工程由Esteban Morales领导,他将该结构系统呈现为由竹拱和分裂竹梁构成的五个相交的双曲抛物面。
竹子的拉伸强度与重量之比通常超过钢铁,使其不仅坚固而且轻巧。灵活性是另一个优势:特别是在分裂形式下使用,竹子使得建筑师能够塑造有机而流动的形状,突破传统几何限制,促进采用依赖形状刚度和仿生学的创新结构方法。竹子的快速生长和固碳能力也使其成为环境上优越的替代传统建筑材料(包括木材)的选择。
The architectural vision was conceptualized by the CO-LAB Design Office, brought to life by Architectura Mixta, and inspired by the iconic work of legendary architect Felix Candela. The engineering was led by Esteban Morales, who describes the structural system as five intersecting hyperbolic paraboloids made of bamboo arches and split bamboo beams.
Bamboo’s tensile strength-to-weight ratio often surpasses that of steel, making it not just strong but also lightweight. Flexibility is another advantage: especially when used in split form, bamboo enables architects to craft organic, flowing shapes that defy traditional geometrical constraints, facilitating the adoption of innovative structural approaches that rely on shape stiffness and biomimicry. Bamboo’s rapid growth and ability to sequester carbon also position it as an environmentally superior alternative to traditional construction materials, including timber.
Luum Temple卢姆神庙 / CO-LAB设计事务所
Luum Temple / CO-LAB Design Office. Image © César Béjar
另一方面,使用竹子也需要在某些方面进行特别注意。由于竹子的轻巧特性,必须特别关注基础、交叉支撑和结构刚度,这些对于抵抗风力的作用至关重要。尽管竹子的剪切强度较低,但对其性能的充分理解可以通过创造性的系统来弥补这一问题,同时对处理过程进行关键性关注也是不可或缺的。竹子还容易受到昆虫侵袭,并且寿命有限,因此在任何基于竹子的建筑中,包含积极的“设计保护”方法成为了重要的环节。
On the other hand, working with bamboo also requires special care in certain aspects. Due to its lightweight nature, particular attention must be paid to foundations, cross-bracing and structural stiffness, which are essential to counterbalance its vulnerability to wind forces. Although bamboo's low shear strength presents a challenge, an adequate comprehension of its properties allows for creative systems to compensate for this, and a critical focus on treatment is also non-negotiable. The material can also be prone to insect attacks and has a limited lifespan, making it important to include proactive 'preservation by design' approaches as an integral part of any bamboo-based construction.
竹节,用带子和别针固定,产生合适的结构元素。
Bamboo splits, secured by straps and pins produce well-suited structural elements. Image © Luum Temple: A Practical Guide to Engineering Split Bamboo Spatial Gridshells
卢姆神庙在这些优势和挑战之间取得了平衡。例如,屋顶膜片采用了交叉层叠的竹席,这致敬了过去经验性技术,使结构具有出色的抵抗横向荷载的能力。为了适应竹子的自然弯曲和运动,该结构采用了关节式基础和中央压力环。这种方法不仅充分利用了竹子的内在优势,而且规避了其局限性,展示了一种可持续和创新建筑的典范方式。
工程流程
卢姆神庙项目的一个显著特点是成功将最新的竹子工程概念与永恒的建筑框架相结合。工程团队不仅仅是按照标准程序进行工作,他们通过开发定制方法,进入了新的领域,同时遵循国际公认的标准。这种创新的方法巧妙地在墨西哥复杂的竹子建筑监管框架中穿行,为未来的竹子项目树立了坚实的先例。
该项目的技术工作流程得到了强大的软件工具包的支持。结构设计过程始于AutoCAD 3D,通过该软件对结构的几何形状进行建模并进行兼容处理,为后续步骤做好准备。随后,采用专业的结构分析软件SAP2000 v.14进行结构分析。
The Luum Temple embraces a balance between these advantages and challenges. The interconnected roof diaphragm, for instance, is made of cross-layers of bamboo mats —a modern nod to empirical techniques of the past that give the structure impressive resistance to lateral loads. To account for bamboo's natural flex and movement, the structure incorporates articulated foundations and a central compression ring. This approach not only captures bamboo's intrinsic strengths but also circumvents its limitations, demonstrating a model way to build sustainably and innovatively.
The Engineering Process
A defining feature of the Luum Temple project was its successful integration of up-to-date bamboo engineering concepts with a timeless architectural framework. Rather than merely following standard procedures, the engineering team ventured into new territory by developing custom methods, all while adhering to internationally recognized standards. This inventive approach adeptly navigated through Mexico's intricate regulatory framework surrounding bamboo construction and also set a solid precedent for future bamboo projects.
The technical workflow of the project was facilitated by a robust software toolkit. The structural design process started with AutoCAD 3D, where the structure’s geometry was modeled and compatibilized for the next steps. Following this, structural analysis was carried out using specialized structural analysis software SAP2000 v.14.
AutoCAD几何图形导出到SAP2000 V.14的样子。
AutoCAD geometry for export to SAP2000 V.14. Image by Esteban Morales. Image © Luum Temple: A Practical Guide to Engineering Split Bamboo Spatial Gridshells
结构的3D模型在结构软件SAP2000中可以看到。
The structure’s 3D Model as seen in structural software SAP2000.. Image © Luum Temple: A Practical Guide to Engineering Split Bamboo Spatial Gridshells
该结构划分为三种主要元素类型,以确定设计过程的方向:
1. 拱形结构,从结构的边缘和中心径向跨度延伸;
2. 椽子,跨越多层并连接主要拱形结构;
3. 屋顶膜片,由多层椽子三角形和屋顶下方的分割编织形成的刚性表面。
由于该项目位于一个容易受到飓风和地震活动影响的地区,工程策略强调形状刚度、三角形结构和坚固的膜片。这些元素被特别选择用来抵消可能危及结构的横向力。因此,结构中的每个组件都相互连接并协同工作,确保对抗自然界最极端力量的韧性。
在负荷大小方面,显著的地震荷载和250公里/小时的飓风风载控制了设计。这些荷载与自重(结构和屋顶的重量)和活载相结合,以获得每个结构元素的设计内力。为此,采用了允许应力法,符合结构竹子设计的最适方法。然后,根据竹子特定的结构规范,乘以荷载系数。最后,考虑到最受力的拱形结构、椽子和屋顶膜片元素中的最大内力,进行了结构元素的最终设计。
The structure was divided into three main element types to orient the design process:
1.Arches, spanning in the edges of the structure and radially from the center;
2.Joists, spanning in layers and connecting the main arches over several layers;
3.Roof diaphragm, conformed by the rigid surface resulting from several layers of joist triangulation and split weaving below the roof.
As the project is located in a region prone to hurricane winds and seismic activities, the engineering strategy emphasized shape stiffness, triangulation, and a robust diaphragm. These elements were specifically selected to offset lateral forces that could compromise the structure. Consequently, each component in the structure was interconnected and designed to function cohesively, ensuring resilience against some of nature's most extreme forces.
In terms of load magnitudes, considerable seismic loads and 250km/h hurricane wind loads governed the design. These were combined with dead loads (weight of the structure and roofing) and live loads to obtain the design internal forces for each element of the structure. For this, the allowable stress method was employed, complying with the most adequate approach for structural bamboo design. The loads were then multiplied by the prescribed load coefficient for each of the required load combinations according to bamboo-specific structural codes. Finally, the maximum internal forces found in the most stressed arch, joist, and roof diaphragm elements were considered for the final design of the structural elements.
风力引起的位移以蓝色突出显示,表示最大移动区域。
Wind-induced displacements highlighted in blue, indicating areas of maximum movement. Image © Luum Temple: A Practical Guide to Engineering Split Bamboo Spatial Gridshells
凭借对结构内力在每种荷载组合中的作用等结构洞察,结构组件的设计基于竹子特定的建筑规范,例如NSR-10(哥伦比亚)和ISO 22156(国际)。然后使用WoodWorks® Connections、SFS Timber Work和APF Wood Joint等专业软件设计结构组件之间的连接元素。
在结构的最上部,主要的拱形结构汇聚在一起,由中央钢压力环相互连接。这种设计特点确保每个拱顶都会汇聚到一个中心点,类似于星星辐射的臂膀。就像是飞机的机翼,在飞行过程中会有一定程度的弯曲和反弹,以防止结构失效,竹子结构采用了类似的工程原理。为了确保竹子构件在风暴或地震等不利情况下能够弯曲和适应而不断裂,中央压力环采用了坚固的铰链连接,如后续图片所示。
Equipped with structural insights, such as the internal forces acting in the structure for each load combination, the structural components were designed based on bamboo-specific building codes, such as the NSR-10 (Colombia) and the ISO 22156 (International). Specialized software like WoodWorks® Connections, SFS Timber Work, and APF Wood Joint were then employed for the design of the connecting elements between structural components.
At the uppermost part of the structure, the primary arches converge, interconnected by a central steel compression ring. This design feature ensures each arch tip converges towards a centralized point, reminiscent of a star's radiating arms. Drawing a parallel to airplane wings, which flex and bounce to a certain extent during flight to prevent structural failure, bamboo structures adopt a similar engineering principle. To ensure the bamboo components can flex and adapt during adverse events like storms or earthquakes without fracturing, the central compression ring incorporates robust hinged connections, as illustrated in the subsequent images.
卢姆神庙在建造过程中的结构压缩环俯视图。
Top view of the Luum Temple's structural compression ring during construction. Courtesy of CO-LAB design office. Image © Luum Temple: A Practical Guide to Engineering Split Bamboo Spatial Gridshells
卢姆神庙结构压缩环的详细示意图。
Detail schematic of the Luum Temple's structural compression ring. Image © Luum Temple: A Practical Guide to Engineering Split Bamboo Spatial Gridshells
在这个项目中,设计师经过详细的分析,确定了基座处的机械连接方式。连接方式采用类似于中央压力环的铰链设计,使竹子拱形结构与基础之间能够进行旋转运动。这种设计策略确保竹子构件免受过多的剪切和弯曲力的影响,这不是它们的优势。相反,竹子主要承受与其纤维平行的张力和压缩力。
【解释:竹子的纤维结构决定了它在特定方向上的力学性能。竹材的纤维通常以纵向方向为主要承载方向,具有较高的抗拉强度和压缩强度。然而,竹子在横向方向上的力学性能相对较低,包括抗剪切和抗弯曲能力。这是由于竹材的组织结构和纤维排列方式所决定的。
因此,在设计中,为了充分利用竹材的优势,并确保其结构的稳定性和耐久性,需要避免竹材承受过多的剪切和弯曲力。通过在基座处使用铰链连接,可以允许竹子结构进行旋转运动,从而减少对竹子材料的剪切和弯曲力的影响。这样设计的目的是使竹子主要承受与其纤维方向平行的张力和压缩力,以充分发挥其优势并确保结构的稳定性。】
In this project, a detailed analysis was undertaken to determine the mechanical connections at the base. Designed in a hinged manner, similar to the central compression ring, the connections between bamboo arches and the foundation permit rotational movement. This design strategy ensures that bamboo elements are spared from excess shear and bending forces, which aren't their strengths. Instead, the bamboo primarily experiences tension and compression forces parallel to its fibers.
基础系统稳定,防止隆起,同时适应拱门的运动。
The foundation system stabilizes against uplift while accommodating the arches' movements. Image © Luum Temple: A Practical Guide to Engineering Split Bamboo Spatial Gridshells
卢姆神庙在建造时,底部的铰链连接细节。
Detail of the hinged connections at the base of the Luum Temple during its construction. Courtesy of CO-LAB design office. Image Courtesy of CO-LAB design office
正如我们所见,竹子不仅是一种快速可再生的资源,它还是一种能够在未来几十年改变可持续建筑景观的结构材料,它的发展极具潜力。从其历史根源到现代应用,竹子证明了传统与创新的结合能够创造奇迹。
As we've seen, bamboo isn't just a rapidly renewable resource —it's a structural material with the potential to change the landscape of sustainable architecture in the upcoming decades. From its historical roots to its modern-day applications, bamboo proves that when tradition meets innovation, magic happens.
© Luum Temple: A Practical Guide to Engineering Split Bamboo Spatial Gridshells
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