Steel Buildings in Europe

Part 3: Actions 3 - 30  Area of the openings at the dominant face between 2 and 3 times the area of the openings in the remaining faces: Linear interpolation for calculating c pi . When the openings are located in zones with different values of c pe , an area weighted average value should be used. For buildings without a dominant face, the coefficient c pi should be determined from a function of the ratio h / d and the opening ratio  for each direction, as shown in Figure 8.5. where:     openings area of all 0 where openings area of pe c μ Figure 8.5 Internal pressure coefficients for uniformly distributed openings For values between h / d = 0,25 and h / d = 1,0, linear interpolation may be used. Where it is not possible or not considered justified to estimate  for a particular case, then c pi should be taken as the more onerous of + 0,2 and – 0,3. The reference height z i for the internal pressures should be equal to the reference height z e for the external pressures on the faces which contribute by their openings to the creation of the internal pressure. Generally, for single-storey buildings, z i = z e = h and the velocity pressure q p ( z ): q p ( z i ) = q p ( z e ) = q p ( h )