As in the m factor tables, the columns on the left refer
stud shear walls in 7-2i, and steel stud shear walls in
7-2j.
to the applicable condition of the component or
element.
The next three columns provide the
(3) Revisions to ACI 318. Various revisions
appropriate modeling parameters or limit states for
to Chapter 21 of ACI 318 have been approved, but
the various performance levels, as indicated in Figure
have not yet been published (September 1998).
6-2c.
The four columns on the right-hand side
Many of these revisions have been incorporated in
provide the appropriate values for the performance
Chapter 6 of FEMA 302 as modifications to the
levels, as defined in Paragraph (1) above.
referenced provisions of ACI 318. The following
provisions pertaining to mechanical and welded
(3) Symbols and notations contained in the
splices of reinforcement are not included in FEMA
above tables are defined in Appendix B.
302, but have been approved as revisions to ACI 318,
and are incorporated as provisions required by this
(4)
Expected and lower-bound strengths.
document:
Default values for the determination of expected
QCE,
strength,
for
deformation-controlled
components, and the lower-bound strength, QCL, for
(a)
Delete Sections 21.2.6, 21.2.6.1, and
21.2.6.2 of ACI 318.
force-controlled
components,
are
provided
in
Paragraph 6-3a(3). Specific exception to the default
(b) Add the following new sections to ACI
values is provided for some of the systems described
318:
in this chapter.
7-2.
Shear Walls.
"21.2.6 - Mechanical splices
a.
General.
21.2.6.1 Mechanical splices shall be
classified as either Type 1 or Type 2 mechanical
splices, as follows:
(1)
Function.
Shear walls are vertical
elements in the lateral-force-resisting system that
(1)
Type 1 mechanical splices shall
transmit lateral forces from the diaphragm above to
conform to 12.14.3.4.
the diaphragm below, or to the foundation. Shear
walls may also be bearing walls in the gravity-load
(2)
Type 2 mechanical splices shall
system, or they may be components in a dual system
conform to 12.14.3.4 and shall develop the specified
framed so as to resist only lateral loads.
tensile strength of the spliced bar.
(2) Shear wall types. General discussions of
21.2.6.2 Type 1 mechanical splices
shear walls are presented in Paragraphs 7-2b through
shall not be used within a distance equal to twice the
7-2e. Details of reinforced concrete shear walls are
member depth from the column or beam face or from
covered in Paragraph 7-2f, precast concrete shear
sections where yielding of the reinforcement is likely
walls in 7-2g, masonry shear walls in 7-2h, wood-
7-7
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