13-52-300 General lateral loads.

   Provisions for the determination of wind loads on buildings and other structures shall be as follows:

   (a)   The provisions apply to the calculation of wind loads for main wind-force resisting systems and for individual structural components and cladding of buildings and other structures. Special investigations shall be required to determine wind loading for buildings or structures exceeding 600 feet in height, having irregular shapes, response characteristics or site locations with shielding or channeling effects that warrant special consideration, or for cases in which more accurate wind loading is desired.

   (b)   Wind load provisions of Section 13-52-290 are based on a basic wind speed of 75 miles per hour defined as the Annual Extreme Fastest-Mile Speed ten Meters (33 feet) Above Ground. A 50-Year Recurrence Interval has been used in developing Section 13-52-310, minimum design wind pressures.

   (c)   Combined Stresses. For combined working stresses due to dead, live and wind loads, the allowable working stresses in material may be increased one-third, provided the section thus determined is at least as strong as that required for dead and live load alone except that this increase in stresses shall not be permitted for structures as given in Section 13-52-310(f), signs, tanks, towers and chimneys.

   (d)   Overturning And Sliding.

   Overturning. The overturning moment due to the wind load shall not exceed two-thirds of the moment of stability of the building or other structure due to the dead load only, unless the building or other structure is anchored so as to resist the excess overturning moment without exceeding the allowable stresses for materials used.

   Sliding. When the total resisting force due to friction is insufficient to prevent sliding, the building or other structure shall be anchored to withstand the excess sliding force without exceeding the allowable stresses for the materials used. Anchors provided to resist overturning moment may also be considered as providing resistance to sliding.

   (e)   Anchorage. Adequate anchorage of the roof to walls and columns, and of walls and columns to the foundations to resist overturning, uplift and sliding shall be provided in all cases.

   (f)   Stresses During Erection. Refer to Chapter 13-124; Safeguards During Construction.

(Prior code § 68-4.1; Added Coun. J. 11-29-89, p. 8387)