How can you most effectively design a skyscraper so that the solution is viable structurally, architecturally and economically? The following include the top five tips in tackling a project of this nature.
#1 Consider Your Team Carefully
Mobilise your best, most skilled resources involving people with a good holistic understanding of everything involved in a tall building. Fundamental to all this is maximising the developer’s return on his investment. That is done by maximising the saleable area and minimising service zones (lifts, cores, structural elements etc from a horizontal and vertical plane point of view), allowing him to sell of much of the building as possible and reduce the areas that cannot be sold per se.
#2 Try to Avoid Transfer Structures
Minimise or, better still, preclude the need for transfer structures. This has the effect of reducing the building height, reducing building costs, speeding up construction and simplifying construction.
On 568 Collins Street in Melbourne, we achieved the optimum result of no transfer structures and delivering the client the benefits above.
#3 Get Early Wind Analysis Testing
Optimise the building stability solution involving as early as possible wind tunnel analysis and testing. This has the effect of optimising the core elements and any other stability mechanisms, such as shear walls, while also highlighting any challenges associated with wind acceleration.
#4a Get Early Geo-Technical Testing
Optimise your footings solution. Far too often on tall building projects there is a bit of pressure put on engineers to scrimp and save in terms of the amount of testing done. This is false economy. It is critical that you get good and enough information early in the process as it can have a huge difference in the overall cost of the project
#4b And Include Pressuremeter Testing
A simple addition to geotechnical testing, and at a reasonable cost, is to introduce and include pressuremeter testing. We have found that on 3 of the 4 towers we are currently working on in Melbourne with the introduction of this testing a huge benefit from a design and analysis perspective, which we are able to pass back in value terms to the client.
#5 Don’t Underestimate The Importance of Floor Systems
Optimise your flooring systems. Too often people look at floor systems not being that sophisticated and not that important but when you are looking at a tall building and you have elements repeated for 50, 60, 70 levels the influence of those elements is significant in the overall cost analysis.
You can potentially consider a lot of different options, varying from the traditional to the non-traditional. You should therefore factor in when the builder is going to be involved in the project. The earlier he is involved, the more easily more options can be considered and even form part of the tender process. If the builder is involved in a traditional delivery process, it is more often than not that only a traditional solution can be presented.
Competitive tendering is very important in the overall outcome of a project. To achieve an effective process, it is crucial that the options are presented in a clear and understandable format and put to all tenderers and not just to one or two. For that reason it is critical in the decision making process as to what system is to be presented, that it is understood who the tenderers are going to be, if possible, when they are going to get involved and what stage they are going to take ownership of the design.
AUTHOR: Mark Hennessy-Structural Director, Meinhardt Australia
Source: Design Build Source
