Project Description

The project is a fictitious proposal for a competition to design a viewing tower at Aarhus harbour.

The proposed design is a simple and elegant shape that expands over the water. It consists of three primary elements; a core, a platform and a shell. The core has a lift inside it and a spiral staircase on the outside thus enabling the visitors to get to the platform level. The platform itself is located 7.5 m above the ground and facilitates a 360 degree uninterrupted view of the surroundings including Bassin 7, Nicholine Kochs plads, the marina and the old city of Aarhus. The shell is a doubly curved surface, which is discretised into a planar quad mesh in order to build it from flat sheet material. Corten steel is chosen as it blends in well with the industrial harbour site and adds a very distinct visual expression. A planar quad mesh can be generated by tracing the principle curvature lines on an arbitrary surface and a bespoke C# script in Grasshopper has been developed for this purpose. To avoid that the space inside the shell becomes dark and uncomfortable, a number of initiatives have been made; openings are created in each of the quadrilateral elements and scaled according to the stress level in the shell, the platform is made in glass and steel and lights are placed at the bottom of the concrete core to illuminate the viewing tower from the inside at night.

All three primary elements are an active part of the structural system. Vertical loads on the platform are transferred through bending action to the core and the shell, which in turn transfer the forces back to the foundation mainly by compression. When the tower is exposed to wind, the core acts as a cantilever beam with a reaction forces couple at the base. The shell has compressive forces on the pressure side and tension forces on the suction side. The vertical load case is used as basis to determine the different sizes of the openings. The final result is shape that reflects the force flow in the shell thus making the tower more structurally transparent.

About project

Type: Diploma thesis
Supervisors: H. Almegaard, D. Horswill & A. Bak
Time period: 2013 – 2014 (5 months)
University: DTU

Keywords: Form-finding, Shell, Principle curvature lines, PQ mesh, torsion-free nodes, Finite element analysis