Hickory Group, Melbourne
In this presentation, an innovative diagrid-like pattern for tall building structures is proposed. Based on the concept of principal stress trajectories, the pattern is characterized by triangular units with both angle and density varying along elevation, and, being the expression of forces flow arising in the building façades, it is expected to be highly efficient and visually appealing. The idea is to model the building as a three-dimensional vertical cantilever beam with tubular section under horizontal load, and to derive the relevant principal stress lines. Then, the stress analysis results are processed for generating structural grids that satisfy constructability constraints.
For this purpose, a framework for implementing and manage the stress lines concept in the preliminary structural design of tall buildings is proposed; two different procedures are outlined, namely:
- a fully analytical and computer-based procedure, which, starting from the the principal stress vectors of the equivalent cantilever beam, the geometrical pattern is defined by minimizing an objective function;
- a fully hand-calculation procedure, based on Mohr’s circles for deriving the principal stress directions and utilizing an iterative method for the defining the diagonal members arrangement on the building façades.
The effectiveness of the generation procedures and the efficiency of the obtained structural patterns are then verified by means of the application to a tall building model and the comparison with traditional diagrids as well as optimized structural solutions.