Basic Behavior of Unreinforced Bearing Walls Load-bearing masonry (without calculated reinforcement) must be
designed for the effects of
1. Gravity loads from self-weight, plus gravity loads from overlying roof or floor levels
2. Moments from eccentric gravity load, or out-of-plane wind or earthquake
3. In-plane shear
For now, we shall study Loadings (1) and (2). In Sec. 5.3, we shall study Loading (3), in the general context of design of masonry shear walls.
For Loadings (1) and (2), we shall design unreinforced, load-bearing masonry as a series of vertically spanning strips, (Fig. 5.10), subjected to gravity loads (possibly eccentric) and out-of-plane wind or earthquake.
The only aspect of behavior that we haven’t studied so far is the effect of slenderness on the load-carrying capacity of a column or wall. This effect is shown in Fig. 5.11.
At low values of slenderness, a masonry column in compression exhibits material failure. At high values of slenderness, it exhibits stability failure.
For masonry design, the effective length coefficient, k, is usually equal to 1.