Concept About The Complex Structure Part -1

6 Jan 2018

Civil Engineer

We all have lots of problems to face when it comes to creating a complex structure.Mainly here we are discussing the facts and figure of start a complex structure.Mainly what I understand with a word complex in Structure.

Complex structure means a structure having lots of profile means a way that doesn't exist in standard never has any history to build, the elevation has different looks, mainly the structure you see awesome to you means it has some extraordinary things on it, that's not present in a standard structure.

In this blog, I shortly state the way I use to make a complex structure and the inspiration mostly comes from.

So I want to start with the building design, and here I discuss about the twisted tall Building.

Complex Building Design

Before you go for the Modern complex structure you have to know the history of the complex structure.
At Present we can see the structure tapered, circular, angular, so lots of varieties are present there.
But  when you talk about the past, the tall buildings(skyscrapers) you could have hardly found and the type of  structure  have strong bond with great architectural looks, the main thing is to developed the structure with the strong material because that time the smart ways are far away and they believed in hard work and patience.

For each complex form category, tall buildings are designed with various structural systems, such
as a braced tube, diagrid and outrigger systems, and the structural performance of each system, in conjunction with the building forms and heights are studied. Parametric structural models are generated to investigate the impacts of varying various important geometric configurations of complex-shaped tall buildings, such as the rate of twist, an angle of tilt, an angle of taper and degree of fluctuation of free form.

So Tall buildings emerged in the late 19th century in Chicago and New York. After decades of eclectic design in the early
The 20th century, the International Style prevailed during the mid-20th century and produced numerous prismatic Miesian
style towers all over the world.

 Ideas Came From 

Today’s architecture, including tall buildings, can be understood only through recognition of the dominance of pluralism. This contemporary architectural design trend has produced various complex-shaped tall buildings, such as twisted, tilted, tapered and freeform towers, as are the cases with the twisted Cayan Tower in Dubai, tilted Gate of Europe Towers in Madrid and tapered freeform Phare Tower in Paris. This paper studies performance-based structural system design options for various complex-shaped tall buildings.
Tall buildings carry very large gravity and lateral loads. Therefore, structural impacts of twisting, tilting, tapering and free-forming tall buildings are significant, and more careful studies are required for the design and construction of complex-shaped tall buildings.

Twisted Building Design Method

The twisted tall building is the most magnificent and most wonderful structure in the world. so how we can build this ?the purpose of this structure, I let you know all these things and share all the unknown facts about this.Employing twisted forms for tall buildings is a recent architectural phenomenon. 

Twisted forms employed for today’s tall buildings can be understood as a reaction to rectangular box forms of modern architecture. In fact, this contemporary architectural phenomenon is not new in architecture. It is comparable to twisted forms of Mannerism architecture at the end of Renaissance architecture. 

For example, in Cortile della Cavallerizza at Palazzo Ducale in Mantua, Giulio Romano designed twisted columns. Twisted
forms can be found again in today’s tall buildings, such as the Shanghai Tower in Shanghai designed by Gensler,
Infinity Tower in Dubai by SOM, and Chicago Spire project in Chicago by Calatrava.

In terms of static response, twisted forms are not structurally beneficial. Fig.  shows prismatic and twisted
towers with a square plan. If solid towers are considered, the moment of inertia of a square plan does not change regardless of its twisted angle. However, if building type structures composed of many frame members are considered, the lateral stiffness of the twisted tower is smaller than that of the square tower [2].

Both diagrids and braced tubes are very efficient structural systems for tall buildings of conventional shapes, such as rectangular box form towers. If these structural systems are employed for twisted tall buildings, the systems’ lateral stiffness decreases as the rate of twist increases. 

The stiffness reduction of braced tubes, composed of verticals and diagonals, is much more sensitive to the rate of twist, compared to that of diagrids, composed of only diagonals.And this sensitivity is accelerated as the building height increases.The phenomenon of twisting can be the most important to stabilize.

Stable Functionality

Lateral load-carrying mechanism of outrigger structures is different from that of tube type structures, such as diagrids and braced tubes. Both lateral shear forces and overturning moments are carried by perimeter diagrids and braced tubes in the perimeter tube type structures [3], [4].

 In outrigger structural systems with braced core structures, the braced cores carry lateral shear forces and a portion of overturning moments. Perimeter mega-columns connected to the stiff braced core structure through outrigger trusses also significantly contribute to the bending rigidity in the outrigger structural system [5].

 As the outrigger structure is twisted, the perimeter mega-columns wrap around the building spirally. Lateral stiffness of the outrigger structures with these spirally slanted perimeter mega-columns is substantially reduced as the rate of twist increases. Fig. 4 shows an example of twisted outrigger structures and Fig. 5 summarizes the maximum lateral displacements of twisted outrigger structures of various heights and rates of twist. It clearly shows the decreased lateral stiffness of the twisted outrigger structures with the increased rate of twist.

So overall I hope you understood all the facts and figures to start the complex structure of the twisted building.Here I discussed the Twisted building partly on my next blog I also share the tilted structure.

Start with Revit Architecture

now in Revit, you can build or create this type of building in two process 
1) solid structure
2)Massing Structure.
What I think that is you should go for massing, there have lots of problems you may have faced when you go for the solid structure.because by solid form you have some limit, after the limits you could have the ability to beyond that level.
But in massing structure, you have a great space to create the complex structure of Cayan Tower.
Massing and Site part gives you the easiest facility to create this type of structure.
I will try to cover this missing part also for this complex structure.

Before ending I am very much thankful to Mr.Kyoung Sun Moon to write a great and knowledgeable Article in the year 2015, it was published in International Journal of Engineering and Technology 2015.

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