For those who know their history well (wink, wink) Valyria was the capital city of the once-great civilization known as the Valyrian Freehold. The city was located on the eastern continent of Essos. (PS – If you haven’t watched Game of Thrones, you can completely ignore this first paragraph).
While the city is fictitious, and the Valyrian part is mere fantasy, there is a real, near-magical material called steel. Yes – it has been used to weapons of war in years gone by… but we’ve found a more constructive use for it: erecting modern corporate castles a.k.a high-rise buildings.
Buildings framed in high strength steel come in different forms and configurations. Some even use composite members that utilize both steel and concrete. What they have in common is that they are strong, relatively fast to build and light in weight. They are also not as wasteful during construction as alternative methods. Thus they save overall cost and are green – making them quite popular with developers.
Steel framed buildings have been gaining popularity all over the world. The traditional markets of the US and UK are now joined by China, India, the Middle East, Central America and even some African countries.
South Africa was one of the pioneers of the use of steel framed buildings at the end of the 19th century. The Jaggers building in Cape Town was one of the first steel framed buildings in the world. The Johannesburg Post Office, constructed in 1890, is another example of the novel use of steel framed floor systems.
Several steel framed buildings continued to be constructed in the 20th century including high rise buildings in Johannesburg CBD in the 1980s and 1990s. A few Steel framed buildings continue to be constructed primarily in Gauteng and the Western Cape.
Modular construction of multi-storey steel framed buildings is an exciting area of emerging construction. There are several interesting examples of such construction in the US and Europe but currently very few in South Africa.
Off-site fabrication of modules helps in at least three ways. Firstly it is safer to build things in the factory, on the ground level, than it is at height on site. Secondly work done in a factory is typically of much higher quality – and easier to inspect – than work done on site. Finally much time can be saved by integrating services and insulation in modular parts at the factory as compared to completing this work by utilizing separate and sequential trades on site.
It is notable that engineers at the SAISC have invented a novel modular office building system and the Institute is presently busy with Research and Development work to explore the concept. Much of the Institute research focuses on fire resistance because one of the main challenges with mutli-story buildings has to do with safety during accidental or Targaryen fires.
South African engineers are adequately trained to understand how buildings respond to common human and environmental loads. In some instances however, such as during flooding, fires or earthquakes, this knowledge may be found to be lacking. Engineers at the SAISC continue to support research, training and SABS standards development to help where these gaps exist.
Another exciting recent development involves the use of Building Information Modelling (BIM). This technology lends itself to the construction of modular mutli-storey steel framed buildings because it allows all of the procurement, fabrication and erection to be modelled before the actual construction commences. This can help avoid expensive surprises and thus reduce delays and unanticipated costs.
As a grand finale, it is exciting to build beyond “Valyrian” heritage and make use of high strength steel in new ways. Multi storey buildings must be able to operate as safe living and working spaces for thousands of people. As such, they need to withstand various environmental and enemy induced hazards. The probability of collapse or loss of life due to such hazards must be kept very small, and steel provides incredible material properties to achieve this.
The alternative is the wrath of the Iron Throne – something to behold.
