Seismic Design Requirements
General
Masonry structures and masonry elements shall comply with the requirements of Sections 10.3 through 10.7 based on Seismic Performance Categor A, B, C, D, or E as deined in ASCE 7.
Manufacturer's Comment: Seismic performance category A and B standards for masonry structures has no additional requirements for joint reinforcing and accessories.
Seismic Performance Category C
Reinforcement requirements for masonry elements - Masonry elements shall be reinforced in either the horizontal or vertical direction in accordance with the following:
(a) Horizontal reinforcement - Horizontal joint reinforcement shall consist of at least two longitudinal W1.7 (9ga) wires spaced not more than 16 in. (406 mm) for walls greater than 4 in. (102 mm) in width and at least one longitudinal W1.7 wire spaced not more than 16 in. (406 mm) for walls not exceeding 4 in. in width; or at least one No. 4 bar spaced not more than 48" (1219 mm). Where two longitudinal wires of joint reinforcement are used, the space between these wires shall be the widest that the mortar joint will accommodate. Horizontal reinforcement shall be provided within 16 in. (406 mm) of the top and bottom of these masonry elements.
(b) Vertical reinforcement - Vertical reinforcement shall consist of at least one No. 4 bar spaced not more than 48 in. (1219 mm). Vertical reinforcement shall be located within 16 in. (406 mm) of the ends of masonry walls.
Minimum reinforcement requirements for masonry shear walls - Horizontal joint reinforcement shall consist of at least two wires of W1.7 (9 ga) spaced not more than 16 in. (406 mm); or bond beam reinforcement shall be provided of at least 0.2 in.2 (129 mm2) in cross-sectional area spaced not more than 10 ft (3.1 m). Horizontal reinforcement shall also be provided at the bottom and top of wall openings and shall extend not less than 24 in (610 mm) nor less than 40 bar diameters past the opening; continuously at structurally connected roof and floor levels; and within 16 in. (406 mm) of the top of walls.