When determining wind load pressures for components and cladding loads, areas of discontinuity in a building (i.e. building corners) have a zone where the Gcp value is increased. This results in wind pressures that have higher values within the width of the discontinuity.
In the October 2014 SE University session, Designing for ASCE 7-10 Wind Loads – Components & Cladding, Don Scott, SE, from PCS Structural Solutions, was asked about curved structures in plan, and whether a curve would be considered a discontinuity.
Don indicated that while the ASCE 7 code does not specifically address curved structures in plan, there is research that has been done in wind tunnels which indicates that if the internal angle of the curved surface is less than 170⁰, then the curve should be treated as a discontinuity. While this is not addressed in ASCE 7, it is addressed in a document released by the American Architectural Manufacturers Association. AAMA TIR-15-14, Overview of Design Wind Load Determination for Fenestration Systems is available through the AAMA’s Publication Store.
Website Link – News regarding AAMA TIR-15-14
In this 2:00 video clip from the Q&A Discussion after the October session, Don talks about when a curved surface should be treated as a discontinuity.