This image was recently sent to us by structural engineer Philip Wilson and shows of John Corpe, Steven Ball of Firman Glass Projects and Philip Wilson (left to right). It shows us analysing the failure of a test beam whilst undertaking an extensive testing project at City University, London for the famous Yurakucho Glass canopy, Tokyo.
This ground breaking 10.6m long canopy, located in the plaza of the Tokyo International Forum, was designed by Rafael Vinoly Architects and engineered by Tim MacFarlane of Dewhurst MacFarlane and Partners, now Glass Light and Special Structures Limited. The canopy shelters an 8m x 4.8m wide staircase well leading to the Yurakucho underground station.
The supporting structure comprises beams that cantilever 9.2m. Each beam has four component beams, made of laminated glass and acrylic blades, pinned at their middle and end points to form an arch. The blades are connected by stainless steel pins to T-shaped brackets, which support the glass panels that form the canopy roof. At the base of the canopy, V-shaped stainless steel brackets connect each cantilever to a horizontal beam running the full width of the canopy.
Special consideration had to be made in the entire design and construction process for the susceptibility of the Tokyo region to earthquakes and other natural disasters. Firman Glass Projects worked closely with Dewhurst MacFarlane and Partners in the testing project, as well as the manufacture of the glass and highly engineered stainless steel fixings.
The very first tests we carried out on the steel and concrete test rig failed before the glass, demonstrating that the principal of building an all glass canopy in a zone susceptible to earthquakes and typhoons was possible. These test results went on to form the groundwork for subsequent designs for multiple glass structures including those of a certain well-known computer manufacturer.
The Yurakucho Glass canopy was completed in 1996 at a budget of $2.5 million. Since completion the canopy has already withstood several earth tremors, typhoons, and the 9.0 magnitude 2011 Tohoku earthquake and subsequent tsunami that was the most powerful ever recorded earthquake to hit Japan. At the 1997 British Construction Industry Awards, the Yurakucho canopy received a special commendation for demonstrating British expertise in the design and construction of glass structures.