First Prize winner
Fast+Epp Architecture and Engineering Design Competition 2018
Designer: Valerine Chandrakesuma
Engineer: Weijun Zeng
We are proposing a design full of colour and history featuring 10,000 used skateboard decks as part of our timber canopy structure for UBC Skate Park. A standard skateboard deck consisted of seven ply plank of hardwood maple, engineered to withstand forces of skaters’s weights and ruthless tricks they perform. In addition to showcasing the strength of this material performing as structural component of the canopy, re-purposing used skateboards brings up another layer of meaning; each one of then is an artifact of countless hours of skating with its own unique history.
This canopy was designed to be a two-hinged semi-circular arch with approximate length of 41m and width of 18.8 to 21.5m. canopy consists of 8 timber beams in the transverse (shorter) direction, with equal spacing of 5.3m. Between adjacent beams, three used skateboard decks would be laminated as one joist element that are assembled together to build up a joist system which has a similar shape as the honeycomb. Prior to assembly, each used decks are sanded to remove paint and stickers before laminated into one joist element. Despite the paint removal, each skateboard decks wills exhibit it’s unique aesthetic due to some colour retained by wood overtime of usage. Each joist elements are connected to one another with bolts, located at the pre-existing 8 holes on the skateboard deck that were used to attach its hardware. Such joists would help transfer the loads and prevent the local buckling of the beams, as well as supporting the waterproof polycarbonate roof membrane resting on top of the joist system at each bay. This lightweight and translucent material filters and direct sunlight into softer and ambient light quality for the interior that are easy to the eyes.
This semi-circle shape blends horizontal and vertical plane seamlessly, allowing continuity of pattern created by skateboard deck assembly from one end of the site to another. Structural reasons for using the semi-circle shape are to 1) spread the snow load over the surface of the structure; 2) provide a favourable moment resistance for a long span. This edge to edge span allow the structure to have as little disruption as possible to the preexisting site. Tailoring to the irregular shape of the site, some of the semicircular beams were intercepted by site edges and prematurely curved to become vertical elements. Such design moves allows existing trees at site to continue to grow uninterrupted by the new canopy structure. In addition, the absence of vertical joist elements at these intercepted part of the beams also resulted in a more welcoming entrances to the north-west and northeast end of the park. On the south side, these joist element went all the way to the ground, replacing the function of the existing railing on the site.
To determine the size of the beams and thickness (number of lamination) of the skateboard joist, the snow load of 2kPa and seismic load of 0.15W was used for the design. By using SAP 2000, the governing reactions were obtained to be the bending moment on beams and the compressive load on the columns. And from the selection tables, the beam size was determined to be 215 x 418mm, while the skateboard joist size was 38 x 200mm