Section 503C — DEFINITIONS — San Francisco Building Inspection Commission Codes

For the purpose of this chapter, the applicable definitions in this code shall also apply.

COLLAR JOINT is the vertical space between adjacent wythes and may contain mortar.

CROSSWALL is a new or existing wall that meets the requirements of Section 511C.3. A crosswall is not a shear wall.

CROSSWALL SHEAR CAPACITY is the allowable shear value times the length of the crosswall, vcLo.

DIAPHRAGM EDGE is the intersection of the horizontal diaphragm and a shear wall.

DIAPHRAGM SHEAR CAPACITY is the allowable shear value times the depth of the diaphragm, vuD.

ESSENTIAL FACILITY is any building or structure classified in Risk Category IV of ASCE 7-16 Table 1.5-1.

HAZARDOUS FACILITY is any building or structure classified in Risk Category III of 7-16 Table 1.5-1.

NORMAL WALL is a wall perpendicular to the direction of seismic forces.

OPEN FRONT is an exterior building wall line, without vertical elements of the lateral force resisting system in one or more stories.

PARTY WALL is a wall common to two or more buildings located on separate parcels of land.

POINTING is the partial reconstruction of the bed joints of an unreinforced masonry wall as defined in Section 516C.

QUALIFIED HISTORICAL BUILDING is a building or structure as defined in the June 1, 1990, Edition of Title 24, California Code of Regulations, Part 8, Section 8-302.

UNREINFORCED MASONRY includes burned clay, concrete or sand-lime brick, hollow clay or concrete block, plain concrete and hollow clay tile. These materials shall comply with the requirements of Section 506C.

UNREINFORCED MASONRY WALL is a masonry wall in which the area of reinforcing steel is less than 25 percent of the minimum steel ratios required by this code for reinforced masonry. To qualify, reinforcing steel must have been installed in grouted cells within the masonry.

UNREINFORCED MASONRY BEARING WALL is an unreinforced masonry wall which provides the vertical support for a floor or roof for which the total superimposed load exceeds 200 pounds per linear foot (298 kg/m) of wall.

YIELD STORY DRIFT is the lateral displacement of one level relative to the level above or below at which yield stress is first developed in a frame me mber.