504C.1 For the purpose of this chapter, the applicable symbols and notations in this code shall apply.

504C.1 For the purpose of this chapter, the applicable symbols and notations in this code shall apply.

A = cross sectional area of unreinforced masonry pier or wall, square inches.

Ab = total area of the bed joints above and below the test specimen for each in-place shear test.

Cp = numerical coefficient as specified in Table 5C-C for Special Procedure diaphragm shear transfer.

D = in-plane width dimension of pier, inches, or depth of diaphragm, feet.

DCR = demand-capacity ratio specified in Section 511C.4.2.

Fwx = force applied to a wall at level x, pounds.

H = least clear height of opening on either side of a pier, inches.

h/t = height-to-thickness ratio of an unreinforced masonry wall. Height, h, is measured between wall anchorage levels and/or slab-on-grade.

L = span of diaphragm between shear walls, or span between shear wall and open front, feet.

Lo = length of crosswall, feet.

Li = effective span for an open front building specified in Section 511C.8, feet.

PD = superimposed dead load at the location under consideration, pounds. For determination of the rocking shear capacity, dead load at the top of the pier under consideration shall be used.

PD+L = stress resulting from the dead plus actual live load in place at the time of testing, pounds per square inch (psi).

Pw = weight of wall, pounds.

Va = vaA, the allowable shear in any unreinforced masonry pier, pounds.

Vca = total shear capacity of crosswalls in the direction of analysis immediately above the diaphragm level being investigated, åvcLo, pounds.

Vcb = total shear capacity of crosswalls in the direction of analysis immediately below the diaphragm level being investigated, åvcLo, pounds.

Vp = shear force assigned to a pier on the basis of its relative shear rigidity, pounds.

Vr = pier rocking shear capacity of any unreinforced masonry wall or wall pier, pounds.

Vtest = load at incipient cracking for each in-place shear test per Section 514C, pounds.

Vwx = total shear force resisted by a shear wall at the level under consideration, pounds.

va = allowable shear stress for unreinforced masonry, pounds per square inch (psi).

vc = allowable shear value for a crosswall sheathed with any of the materials given in Table 5C-D or 5C-E, pounds per foot.

vt = mortar shear strength as specified in Section 506C.3.3.4, pounds per square inch (psi).

vto = mortar shear test values as specified in Section 506C.3.3.4, pounds per square inch (psi).

vu = allowable shear value for a diaphragm sheathed with any of the materials given in Table 5C-D or 5C-E, pounds per foot.

ΣvuD = sum of diaphragm shear capacities of both ends of the diaphragm, pounds.

ΣΣvuD = for diaphragms coupled with crosswalls, ΣΣvuD includes the sum of shear capacities of both ends of diaphragms coupled at and above the

level under consideration.

W = total seismic dead load as defined in San Francisco Building Code Chapter 16, pounds.

Wd = total dead load tributary to a diaphragm, pounds.

Σwd = total dead load to all the diaphragms at and above the level under consideration, pounds.

Ww = total dead load to an unreinforced masonry wall above the level under consideration or above an open front building, pounds.

W w x = dead load of an unreinforced masonry wall assigned to Level x halfway above and below the level under consideration, pounds.