TM 5-809-3/NAVFAC DM-2.9/AFM 88-3, Chap. 3
loads on various elements, thus resulting in a conservative design. In some cases a few additional reinforcing
bars, at little additional cost, can greatly increase the strength of shear walls with openings. However, when
the reinforcement requirements or the resulting stresses of this approach appear excessively large, a rigorous
analysis may be justified.
7-8. Shear Wall Rigidity Analysis. The rigidity of a shear wall element is inversely proportional to its
deflection, thus rigidity has units of kips per inch. The relative rigidity of a wall element is usually obtained
by inverting the deflection caused by a unit horizontal load. The parameters in the rigidity equations for shear
wall elements are: the dimensions of height, length, and thickness; the modulus of elasticity, Em; the modulus
of rigidity or shear modulus, Ev; and the fixity conditions of support of the wall element at top and bottom.