Calculation of design wind pressures is given in Section 27.4-1 and it is calculated as follows:

p = q GfCp- qi(GCpi)

(27.4-1)

However, it is assumed that internal pressures cancel each other for the main resisting systems so that the above equation is simplified to

p = q GfCp

G: Gust factor calculated according to Section 26.9-10.