The two-story building shown in Figure is an elementary school located on a flat terrain in a suburban area, with a wind speed of 102 mph and exposure category B. What is the wind velocity pressure at roof height for the main wind force resisting system (MWFRS)?

The two-story building shown in Figure  is an elementary school located on a flat terrain in a suburban area, with a wind speed of 102 mph and exposure category B. What is the wind velocity pressure at roof height for the main wind force resisting system (MWFRS)?

Fig. 2.5. Two – story building.

Solution

The mean height of the roof is h = 20 ft.

Table 26.10-1 from ASCE 7-16 states that if the exposure category is B and the velocity pressure exposure coefficient for h= 20′, then Kz = 0.7.

The topography factor from section 26.8.2 of ASCE 7-16 is Kzt = 1.0.

The wind directionality factor for MWFRS, according to Table 26.6-1 in ASCE 7-16, is Kd = 0.85.

Using equation 2.3, the velocity pressure at a roof height of 20′ for the MWFRS is as follows: