A contractor of wooden building required an enclosed shelter that would
allow outdoor work to proceed even in inclement weather, but the structure
had to be simple enough for a crew to spontaneously assemble by themselves.
Due to the conditions of the site as well as the conditions for use, a
large arched roof spanning 27m, 8m in height at the center and covering
a space 23m wide was created. Since the paper tubes could not be curved,
the entire arch was divided into 1.8 x 0.9m modules. Lateral stability
is accomplished through the use of structural plywood instead of metal
bracing. Each panel of plywood is pierced by a circle made as large as
possible without compromising its structural integrity, in order to let
natural light stream in through the corrugated poly-carbonate panels covering the dome. To
minimize the expansion and contraction of the paper tubes caused by humidity
over time, the tubes are waterproofed with a clear, liquid urethane. The
ends of the paper tubes and the joints are flush with each other to transfer
the loads and reduce the bending moment. There are reinforcing steel tension
rods and braces used as a precaution against sudden changes of load.