Tree Column Structural System: Biomimicry Application on Lightweight Structures That Dazzle...

Tree column structural system is Biomimicry form on lightweight structures that dazzle

In building design, a lightweight structure requires less material and therefore provides maximum and rational use of materials. Introducing optimal load bearing geometry provides sufficient strength and consequently reduces the waste of resources. Biomimicry/Dendiform application serves this purpose.

The German architect and scientist Frei Otto is the pioneer of form-finding processes through biomimicry from nature. He did lot of experimentation in form finding using lightweight structural materials both in compression and tension. Look at nature how a tree carries it's weight through branching as it becomes taller and spreads to the top. Biomimicry or dendiform, for example, tree column structure is just one type of morphology used in structural application of supporting lightweight roofing for megaspan structures.

Biomimicry/Dendiform/Tree Column Concepts: Frei Otto, Germany

Branching structures are usually referred to as tree-like structures/columns. However, their action cannot be compared with that of a natural tree. While the branches of a tree are under bending stress, bending forces are systematically avoided in technically constructed tree-like structures (Windfried Nerdinger, 2005). The inner structure of the tree-like columns represents a type of framework that is unique in both design and construction industry. It is not a truss with a triangular structure, which would brace the structure, allows articulation joints between the truss elements, and prevents bending even under alternating loads. In the tree-like column, therefore, the individual elements must be rigidly connected at the joints. A tree-like column is particularly well suited for only the one main load scheme for which it is optimized. All other loading conditions will cause bending stresses within the structure.

Tree Column Morphology/Biomimicry/Dendiform

Usable Softwares: Grasshopper, Revit, Build

Advantages of buomimicry/dendiform structures

Lightweight structures are a complex matter and require a greater intellectual effort rather than a physical one. The basic rules of lightweight structures are (Windfried Nerdinger, 2004):

• Avoid bending stresses.
• Carry compression forces over short distances to avoid stability problems and unnecessary added mass in the struts.
• When compression forces must be carried across long distances, incorporate them into selfstabilizing systems (prestress, e.g., spoke wheels,).
• Give planar components in compression appropriate shape to secure them against stability failure.
• “Short-circuiting” the forces within the load-bearing system can result in lightweight structures, and thereby allow simple foundations.

The architectural articulation of tree column occurs in a great number of amazing building masterpieces that dazzle, pleasing to the eyes, and have lightweight structures (see images below to get the essence):

1. College of Architecture, Clamson University, USA

2. Solar Canopy and Vehicle Energy Station, Chichago Park District, USA

3. WasteGate canopy; Frankfurt, Germany

4. Airport Terminal Buildings, Stuttgart, Germany

5. International Airport Terminal Building, Mumbai, India

6. International Airport Terminal Building, Bengaluru, India

Front View: College of Architecture Clamson University

Front Columns: Colleg of Architecture Clamson University

Interior Columns: College of Architecture Clamson University

Solar Canopy and Fuel Station: Chicago Park District

Tree Colum Canopy: Chicago Park District

WestendGate Canopy: Frantfurt

Airport Terminal Building: Stuttgart

Airport Terminal Building Interior: Stuttgart

International Airport Terminal Building: Mumbai

Entrance International Airport Terminal;Mumbai

International Airport Terminal: Bengaluru, India

International Airport terminal: Bengaluru, India

Over the past 40 years, there was a great improvement in designing lightweight canopy structures for sports’ arenas, metro stations, fuel stations etc Consequently the design approach of removing heavy structures provides lighter and mobile structures.Tree-like structures (columns) find a very effective application in bridge design and other large span structures too. It makes them useful for public buildings such as airport terminal buildings, indoor sport arenas, sheds for metro/railway stations, solar canopies, shopping malls, etc.
The tree columns or structures terminology is used among the Architecture and Engineering community only due to the appearance of the structures and cost effectiveness. However, the structural systems using tree columns have completely different load bearing behaviour as opposed to natural growing trees. 

Recommendation

The above advantages of biomimicry/dendiform application on building structures with tree columns often lead to a saving in cost and aesthetics to support megaspan roof structures (airport terminals, covered car park, indoor stadium etc) over stand alone ordinary steel beam column or RCC structural systems. Studies found that tree column solution is techno-commercially superior to stand alone steel or RCC system. Hope this information would serve as an aid to structural engineers and decision makers to explore and utilise tree column concept more and more in megaspan/long span roof supporting structural applications.

Disclaimer

The contents of this article is for informational purpose only and proper professional guidence must be sought before implementation of tree columns in structural/composite applications. The author has no conflict of interest and acknowledge photo source from google.