Pneumatic structure

A pneumatic structure assembly in the form of a barrel roof which has openings at the opposite ends thereof, comprising:

• at least two pneumatic structure portions which are connected to each other at the ends of the respective structure portions;
• each of the pneumatic structures comprising:
• outer and inner walls of a sheet or membrane material comprising a woven fabric of a polyester or aramid fiber;
• a plurality of partition walls in the form of ribs provided between, and connecting, the outer and inner walls to define a plurality of air compartments in the form of ribs between the outer and inner walls;
• an abutment at an end of each pneumatic structure portion contacting an opposite abutment portion of the other pneumatic structure portion;
• and
• a plurality of openings to allow fluid communication between adjacent air compartments,
• wherein an internal pressure is at least 0.001 kg/cm2-g;
• and
• wherein each pneumatic structure has specific dimensions defined as follows:
• 1.20≦b/a≦1.35
• 1.10≦d/c≦1.35
• 0.2≦a/c≦0.5
• where
• a:
• a maximum opening width of the pneumatic structure;
• b:
• a total width of the pneumatic structure;
• c:
• an effective height between ground and a maximum height of the inner wall;
• and
• d:
• a total height between ground and a maximum height of the outer wall.