§ 27-514 Structural requirements.
AC § 27-514
(a)Tents. Tents shall be guyed, supported, and braced to withstand a wind pressure of ten pounds per square foot of projected area of the tent. The poles and their supporting guys, stays, stakes, fastenings, etc. shall be of sufficient strength and attached so as to resist wind pressure of twenty psf of projected area of the tent.
(b)Air-supported structures.
(1)Air-supported structures shall be anchored to the ground or supporting structure by either ballast or positive anchorage, sufficiently and evenly distributed, and adequate to resist the inflation lift load, the aerodynamic lift load, and the drag (shear) load due to wind impact. The latter factors shall be based on a wind velocity of at least seventy miles per hour, and an estimated stagnation of not less than 0.5q for structures on grade whose height is equal to, or less than, the width of the structure. For greater heights, or for elevated structures, increased anchorage shall be provided, justified by analytical and/or experimental data.
(2)The skin of the structure shall be of such strength, and the joints so constructed, as to provide a minimum dead load strip tensile strength at seventy degrees F of four times the seventy mph design load (inflation and aerodynamic loading). The joints shall provide a dead load strip tensile strength of one hundred sixty degrees F of twice the seventy mph design load (i.e., a factor of safety of four and two respectively). In addition, the material shall provide a trapezoidal tear strength of at least fifteen per cent of the maximum design tensile load. Material and joint strengths shall be so certified by the manufacturer, justified by analytical and/or experimental data.
