A104 Symbols and Notations — 2025 California Existing Building Code

[BS] A104.1 Symbols and notations. For the purpose of this chapter, the following notations supplement the applicable symbols and notations in the building code.

a n = Diameter of core multiplied by its length or the area of the side of a square prism. A = Cross-sectional area of unreinforced masonry pier or wall, square inches (10 [-6] m [2] ). A b = Total area of the bed joints above and below the test specimen for each in-place shear test, square inches (10 [-6] m [2] ). A n = Area of net mortared or grouted section of a wall or wall pier. D = In-plane width dimension of pier, inches (10 [-3] m), or depth of diaphragm, feet (m).

DCR = Demand-capacity ratio specified in Section A111.4.2.

f ′ m = Lower bound masonry compressive strength. f sp = Splitting-tensile strength of masonry. F wx = Force applied to a wall at level x, pounds (N). H = Least clear height of opening on either side of a pier, inches (10 [-3] m).

h/t = Height-to-thickness ratio of URM 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 (m). L c = Length of crosswall, feet (m). L i = Effective diaphragm span for an open-front building specified in Section A111.8, feet (m). P = Applied force as determined by standard test method of ASTM C496 or ASTM E519, pounds (N).

P D = Superimposed dead load at the location under consideration, pounds (N). For determination of the rocking shear capacity, dead load at the top of the pier under consideration shall be used.

P D+L = Stress resulting from the dead plus actual live load in place at the time of testing, pounds per square inch (kPa). P test = Splitting tensile test load determined by standard test method ASTM C496, pounds (N). P w = Weight of wall, pounds (N). R = Response modification factor for Ordinary plain masonry shear walls in Bearing Wall System from Table 12.2-1 of ASCE 7, where R = 1.5.

S DS = Design spectral acceleration at short period, in g units. S D1 = Design spectral acceleration at 1-second period, in g units. v a = The shear strength of any URM pier, v m A/1.5 pounds (N). v c = Unit shear strength for a crosswall sheathed with any of the materials given in Table A108.1(1) or Table A108.1(2), pounds per foot (N/m).

v mL = Shear strength of unreinforced masonry, pounds per square inch (kPa). V aa = The shear strength of any URM pier or wall, pounds (N). V ca = Total shear capacity of crosswalls in the direction of analysis immediately above the diaphragm level being investigated, v c L c , pounds (N).

V cb = Total shear capacity of crosswalls in the direction of analysis immediately below the diaphragm level being investigated, v c L c, pounds (N). V p = Shear force assigned to a pier on the basis of its relative shear rigidity, pounds (N). V r = Pier rocking shear capacity of any URM wall or wall pier, pounds (N). v test = Load at incipient cracking for each in-place shear test performed in accordance with Section A106.2.3.6, pounds (N). v tl = Lower bound mortar shear strength, pounds per square inch (kPa). v to = Mortar shear test values as specified in Section A106.2.3.6, pounds per square inch (kPa). v u = Unit shear capacity value for a diaphragm sheathed with any of the materials given in Table A108.1(1) or A108.1(2), pounds per foot (N/m).

V wx = Total shear force resisted by a shear wall at the level under consideration, pounds (N). W = Total seismic dead load as defined in the building code, pounds (N). W d = Total dead load tributary to a diaphragm level, pounds (N). W w = Total dead load of a URM wall above the level under consideration or above an open-front building, pounds (N). W wx = Dead load of a URM wall assigned to level x halfway above and below the level under consideration, pounds (N). Σ v u D = Sum of diaphragm shear capacities of both ends of the diaphragm, pounds (N). ΣΣ v u D = For diaphragms coupled with crosswalls, v u D includes the sum of shear capacities of both ends of diaphragms coupled at and above the level under consideration, pounds (N).

Σ W d = Total dead load of all the diaphragms at and above the level under consideration, pounds (N).