Page 392 - Design of Reinforced Masonry Structures

WALLS UNDER GRAVITY AND TRANSVERSE LOADS 6.43

FIGURE 6.28 Weld plate connections. (Courtesy: NCMA.)

The eccentricity of the vertical load causes a moment which equals force times the
eccentricity (i.e., M = Pe) at the top of the wall. This moment is assumed to vary linearly
from maximum at the top of wall to zero at the bottom of the wall so that the moment at
the wall midheight is Pe/2. Because the lateral loads can reverse in direction, the effect of
this moment is additive to the wall moment due to the lateral loads, the maximum value of

which is assumed to occur at the midheight of the wall (Fig. 6.29). Note that the moment
due to eccentricity of live load is not to be combined with the lateral load. The total design
moment at the wall midheight may be calculated from Eq. (6.16):

M = wL 2 + Pe (6.16)
8 2
where w = lateral load due to wind or earthquake
P = gravity load
e = eccentricity of gravity load
h = height of the wall