Section 1615A — California Building Code (Title 24, Part 2)

TSUNAMI LOADS

1615 A .1 General. The design and construction of Risk Category III and IV buildings and structures located in the Tsunami Design Zones defined in the ASCE Tsunami Design Geodatabase , or other data determined applicable by the enforcement agency, shall be in accordance with Chapter 6 of ASCE 7, except as modified by this code. [DSA-SS] Tsunami Risk Category for public school, community college and state-owned or state-leased essential services buildings and structures shall be identified and submitted for acceptance by DSA. Determination of the Tsunami Risk Category shall be proposed by the design professional in general responsible charge in coordination with the owner and local community based upon the relative importance of that facility to provide vital services, provide important functions, and protect spe- cial populations. The determination of relative importance shall include consideration of a tsunami warning and evacu- ation plan and procedure when adopted by the local commu- nity

90 2019 CALIFORNIA BUILDING CODE

Copyright © 2019 ICC. ALL RIGHTS RESERVED. Accessed by Kevin Day (kevin.day@dgs.ca.gov), (California Building Standards Commission) Order Number #100735044 on Jul 24, 2019 03:54 PM (PDT) pursuant to License Agreement with ICC. No further reproduction or distribution authorized. Single user only, copying and networking prohibited. ANY UNAUTHORIZED REPRODUCTION OR DISTRIBUTION IS A VIOLATION OF THE FEDERAL COPYRIGHT ACT AND THE LICENSE AGREEMENT, AND SUBJECT TO CIVIL AND CRIMINAL PENALTIES THEREUNDER.

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girder with not less than ³ /8-inch-diameter (9.5 mm) headed shear studs, at a spacing of not more than 12 inches (305 mm) on center, averaged over the length of the member, or other attachment having equivalent shear strength, and the slab contains continuous distributed reinforcement in each of two orthogonal directions with an area not less than 0.0015 times the concrete area, the nominal axial tension strength of the end connection shall be permitted to be taken as half the required vertical shear strength for ASD or one-third of the required shear strength for LRFD, but not less than 10 kips (45 kN).

1616 A .3 Bearing wall structures. Bearing wall structures shall have vertical ties in all load-bearing walls and longitudinal ties, transverse ties and perimeter ties at each floor level in accordance with this section and as shown in Figure 1616.3.

1616 A .3.1 Concrete wall structures. Precast bearing wall structures constructed solely of reinforced or prestressed concrete, or combinations of these shall conform to the requirements of Sections 16.2.4 and 16.2.5 of ACI 318.

1616 A .3.2 Other bearing wall structures. Ties in bearing wall structures other than those covered in Section 1616 A .3.1 shall conform to this section.

1616 A .3.2.1 Longitudinal ties. Longitudinal ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls; or connections of continuous framing members to walls. Longitudinal ties shall extend across interior load-bearing walls and shall connect to exterior load-bearing walls and

STRUCTURAL DESIGN

shall be spaced at not greater than 10 feet (3038 mm) on center. Ties shall have a minimum nominal tensile strength, TT, given by Equation 16 A -40. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.

TT = w LS ≤ α TS (Equation 16 A -40)

where:

L = The span of the horizontal element in the

direction of the tie, between bearing walls, feet (m).

w = The weight per unit area of the floor or roof in the

span being tied to or across the wall, psf (N/m ² ).

S = The spacing between ties, feet (m). α T = A coefficient with a value of 1,500 pounds per

foot (2.25 kN/m) for masonry bearing wall structures and a value of 375 pounds per foot (0.6 kN/m) for structures with bearing walls of coldformed steel light-frame construction.

1616 A .3.2.2 Transverse ties. Transverse ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls; or connections of continuous framing members to walls. Transverse ties shall be placed not farther apart than the spacing of load-bearing walls. Transverse ties shall have minimum nominal tensile strength TT, given by Equation 16 A -24. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.

FIGURE 1616 A .3 LONGITUDINAL, PERIMETER, TRANSVERSE AND VERTICAL TIES

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STRUCTURAL DESIGN

1616 A .3.2.3 Perimeter ties. Perimeter ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls; or connections of continuous framing members to walls. Ties around the perimeter of each floor and roof shall be located within 4 feet (1219 mm) of the edge and shall provide a nominal strength in tension not less than Tp, given by Equation 16 A -41. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.

or connections of continuous framing members to walls. Ties around the perimeter of each floor and roof shall be located within 4 feet (1219 mm) of the edge and shall provide a nominal strength in tension not less than Tp, given by Equation 16 A -41. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.

Tp = 200 w ≤ β T (Equation 16 A -41)

For SI: Tp = 90.7 w ≤ β T where:

w = As defined in Section 1616 A .3.2.1.

β T = A coefficient with a value of 16,000 pounds

(7200 kN) for structures with masonry bearing walls and a value of 4,000 pounds (1300 kN) for structures with bearing walls of cold-formed steel light-frame construction.

1616 A .3.2.4 Vertical ties. Vertical ties shall consist of continuous or spliced reinforcing, continuous or spliced members, wall sheathing or other engineered systems. Vertical tension ties shall be provided in bearing walls and shall be continuous over the height of the building. The minimum nominal tensile strength for vertical ties within a bearing wall shall be equal to the weight of the wall within that story plus the weight of the diaphragm tributary to the wall in the story below. Not fewer than two ties shall be provided for each wall. The strength of each tie need not exceed 3,000 pounds per foot (450 kN/m) of wall tributary to the tie for walls of masonry construction or 750 pounds per foot (140 kN/m) of wall tributary to the tie for walls of cold-formed steel lightframe construction.

SECTION 1617A MODIFICATIONS TO ASCE 7