In order to facilitate a car-free campus in the Education City district of Doha, a new light rail system was developed, necessitating the design of 17 separate canopies to shade the new at-grade tram stops.
Each canopy is a lightweight structure composed of a pre-stressed upper and lower cable net, resisting upward forces and wind suction in the former, and self-weight and downward wind pressure in the latter. The upper and lower cable nets intersect and are linked by stainless steel compression struts and tension rods at each node, depending on their location within the grid.
The tension forces in the cable grids are transferred to stainless steel full locked edge cables. These cables are then connected to six custom shaped hollow steel sections, loaded in compression, which are located in the four corners and in the two midpoints of the longer sides. To stabilize each mast, stainless steel tension rods of 80 mm diameter resolve the tension force down to the foundation level. High strength post-tensioning bars and rock anchors secure the foundation to the earth below.
To keep the local streets of the neighborhood free from overhead wires, each tram is locally charged at the station while loading passengers. As a result, a main electrical line, known as the Overhead Contact System, is integrated into the canopy structure.
The lower cable net is clad with triangular shaped glass panels, using custom shaped stainless steel clamps at each node. Each 3-layer laminated glass panel is fritted and coated for optimum thermal performance. Much more than simple shade structures, these cable net canopies facilitate the tram's operation while also creating distinctive landmarks for the Education City campus.
Gartner / Permasteelisa; HLG Contracting
- Our Scope of Work
conceptual design, construction design (roofs and foundations)