Steel’s malleability and ductility along with cost bends to our will to create ever large span structures. The use of steel is also beneficial during time constraints when steel prefabrication can take place off-site and quick assembly can be achieved on-site with guaranteed precision says
SCOTT KNOX, STUDIO DIRECTOR OF DESIGN, CREATIVE GROUP
What are the major advantages of using steel vis-à-vis conventional materials?
We constantly review technological advancements and update the materials recommended for design and construction. Steel is a preferred material due to its versatility. Steel’s strength to weight ratio enables light weight forms and flexibility in regenerative design projects.
Steel’s malleability and ductility along with cost bends to our will to create ever large span structures. The use of steel is also beneficial during time constraints when steel prefabrication can take place off-site and quick assembly can be achieved on-site with guaranteed precision.
How structural steel can be innovatively used in construction to provide design aesthetics and at the same time offer economical solution?
The widespread use of steel during the industrial revolution evolved after the construction of Eiffel Tower. The range of grades and types of steel available globally is phenomenal. We have several go to steel sections and structural members to construct our most challenging designs. In our Chennai Airport project 508mm dia hot bent circular sections of 355 grades were used for the first time in India to achieve its unique shape. (Pic of Chennai Airport) This truss which shapes the roof has a large span with 24m cantilever.
In our Raipur Airport, the iconic roof of the structure was feasible from analysis software (STAAD) that was used to assimilate more than 14,500 tubular members. Each primary truss used in this roof transfers the load to the steel columns with flaring arms on each end, giving them the name of ‘Tree Columns.’
What trend are we going to witness in next 5-7 years, as far as designing structures with steel is concerned?
The most significant steel trend is that the design, detailing, and construction process is being tuned. Thumb-rules were established over millennia from empirical experience. The French developed mathematical models to form bridges and handle the dynamic loading of trains over a century ago. The Towers have risen from the Paris skyline to distant desserts at unbelievable heights and now we design long-span roofs soaring overhead due to our ability to refine the use of steel. Our tools and talent can see where excess lies in a building’s structure. The beauty of this process comes from modelling steel’s strength and using analysis to listen to the material itself. Finite Element Analysis (FEA) is one of many tuning pegs in this trend. As a simple analogy, FEA is a microphone that amplifies the sound of strength in structural design.
Once a tedious and time-consuming task, FEA was mainly used on signature buildings and repetitive structural elements that could afford the time and expense. As the advancement of computational analysis has grown in projects around the world our ability to apply FEA has produced better buildings. There’s something ephemeral about seeing a column or truss that has not 1 KG material than needed. Like nature herself, proportional grace is awe inspiring. We’ve all seen the bulky and awkwardness of overbuild, and the makeshift Jugaad applied around a weak links that fail. Modelling and simulation are the future for all structural design materials. Engineers using FEA modelling tools can listen to each material to refine the design.
Along with the control over structure FEA affords, the Architecture Engineering & Construction (AEC) industry is structurally changing our methods and relationships. In mechanical work Computational Fluid Dynamics (CFD) simulates HVAC performance. In lighting we simulate Lux levels. Architects simulate heat gain, orientation, and acoustics to fine-tune buildings around the people who use them. Now we see how FEA (and all these new methods) are forming the head of a larger trend. That trend is greater than the plethora “business models” floating around, that trend is the rise in use of Building Information Modelling.
BIM is both technology and the relationship between stakeholders in AEC. By geo-locating and centralizing shared information into a single model we are making complex building projects faster, better, and more efficient. The bane of AEC has been excessive redundancy, coordination, and rework at every step. From pre-design to post-occupancy every stakeholder contributes their expertise in the process of developing a virtual model of the building. What does this mean for Steel?
Every building material sector gain from understanding their materials’ potential, proving that potential to other stakeholders, and contributing that knowledge in a meaningful way. In BIM the most meaningful form is “your” smart objects for the design & documentation process. Like the “blocks” of CAD, the parametric “families” in BIM are Steel’s virtual starting point. As we model a structural design a family of steel components gives us more accurate results at the earliest stage of design. By query the model is used to track total tonnage and loading capacity. And FEA? That analysis is performed on the structural BIM model during Schematic and Detail Design stages. At Pre-construction stage BIM clash-detection highlights any point in space where two different assemblies, like a steel beam intersecting an HVAC duct. Query & analysis, design & construction, materials & performance, these are the interdependencies of Building. Now, this global trend incorporating BIM tools and the Stakeholder alignment is a necessity to make design and construction a responsive rather than a tedious process.
Which are the iconic steel-specific projects executed by you?
One example of this potential was stadium design in just 1 day!
At the Parametric Design Conference (UPenn, 2002) the HOK Sports Design Head talked about his vision of designing the form of a stadium with over 50K seat sightlines in just one day. Like FEA, this task used to take months of sampling seats, drawing each seating section to estimate the distance and angle of a fan’s sightline to the middle of the playing field. With parametric modelling seeing the average, min/max for all sightline is quickly and easily demonstrated. During the conference we saw the first iterations of their Virtual Design and Construction (VDC) in practice. But the true goal isn’t just to produce projects quickly, we’re automating the time consuming and tedious tasks to allow people from designers to contractors to focus on the building performance, sustainable, and realize the best design. What results from this change in practice?
Whether we’re developing new airports (Chennai Airport), Train Stations (Charbagh Railway Station.), Metros (Koba Circle), or skyscrapers (Skyone) we’re moving to a new tune. In the industrial age Le Corbusier wrote: “Une maison est une machine-à-habitué”, “A house is a machine for living in”. Currently, I see an AEC industry able to finely tune buildings as “instruments for life”.