TABLE 3403.5.1.1.2
ASCE 41 and ASCE 31 PERFORMANCE LEVELS a
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OCCUPANCY CATEGORY (BASED ON IBC) TABLE 1604.5)
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PERFORMANCE LEVEL FOR USE WITH ASCE 31 AND WITH ASCE 41 BSE-1
EARTHQUAKE HAZARD LEVEL
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PERFORMANCE LEVEL FOR USE WITH ASCE 41 BSE-2 EARTHQUAKE HAZARD
LEVEL
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I
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Life Safety (LS)
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Collapse Prevention (CP)
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II
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Life Safety (LS)
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Collapse Prevention (CP)
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III
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Notea
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Notea
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IV
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Immediate Occupancy (IO)
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Life Safety (LS)
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a Performance Levels for Occupancy
Category III shall be taken as halfway between the performance levels
specified for Occupancy Category II and Occupancy Category IV.
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3403.5.1.1.3 Reduced CBC level seismic forces. When seismic forces are permitted to meet reduced building code levels,
they shall be one of the following:
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a. 75 percent of the forces prescribed in the building code.
The R factor used for analysis in accordance with Chapter 16 of the
building code shall be the R factor as specified in Section 3403.5.1.1.2.
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b. In accordance with the applicable chapters in Appendix A
of the International Existing Building Code as specified in Items
2.1 through 2.5 below. Structures or portions of structures that comply
with the requirements of the applicable chapter in Appendix A shall
be deemed to comply with the requirements for reduced building code
force levels.
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2.1.
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The seismic evaluation and design of unreinforced masonry bearing
wall buildings in Occupancy Category I or II are permitted to be based
on the procedures specified in Appendix Chapter A1.
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2.2.
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Seismic evaluation and design of the wall anchorage system in
reinforced concrete and reinforced masonry wall buildings with flexible
diaphragms in Occupancy Category I or II are permitted to be based
on the procedures specified in Appendix Chapter A2.
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2.3.
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Seismic evaluation and design of cripple walls and sill plate
anchorage in residential buildings of light-frame wood construction
in Occupancy Category I or II are permitted to be based on the procedures
specified in Appendix Chapter A3.
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2.4.
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Seismic evaluation and design of soft, weak, or open-front wall
conditions in multiunit residential buildings of wood construction
in Occupancy Category I or II are permitted to be based on the procedures
specified in Appendix Chapter A4.
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2.5.
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Seismic evaluation and design of concrete buildings and concrete
with masonry infill buildings in all Occupancy Categories are permitted
to be based on the procedures specified in Appendix Chapter A5.
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3403.5.1.2 Wind Design. Wind design of existing
buildings shall be based on the procedures specified in the building
code.
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3403.5.2 Repairs to damaged buildings. Repairs
to damaged buildings shall comply with this section.
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3403.5.2.1 Unsafe conditions. Regardless of the
extent of structural damage, unsafe conditions shall be eliminated.
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3403.5.2.2 Substantial structural damage to vertical elements
of the lateral—force-resisting system. A building that
has sustained substantial structural damage to the vertical elements
of its lateral-force-resisting system shall be evaluated and repaired
in accordance with the applicable provisions of Section 3403.5.2.2.1
through 3403.5.2.2.3.
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3403.5.2.2.1 Evaluation. The building
shall be evaluated by a registered design professional, and the evaluation
findings shall be submitted to the code official. The evaluation shall
establish whether the damaged building, if repaired to its pre-damage
state, would comply with the provisions of the building code. Wind
forces for this evaluation shall be those prescribed in the building
code. Seismic forces for this evaluation are permitted to be the reduced
level seismic forces specified in Code Section 3403.5.1.1.3.
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3403.5.2.2.2 Extent of repair for compliant
buildings. If the evaluation establishes compliance of the
pre-damage building in accordance with Section 3403.5.2.2.1, then
repairs shall be permitted that restore the building to its pre-damage
state, using materials and strengths that existed prior to the damage.
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3403.5.2.2.3 Extent of repair for non-compliant
buildings. If the evaluation does not establish compliance
of the pre-damage building in accordance with Section 3403.5.2.2.1,
then the building shall be rehabilitated to comply with applicable
provisions of the building code for load combinations including wind
or seismic forces. The wind design level for the repair shall be as
required by the building code in effect at the time of original construction
unless the damage was caused by wind, in which case the design level
shall be as required by the code in effect at the time of original
construction or as required by the building code, whichever is greater.
Seismic forces for this rehabilitation design shall be those required
for the design of the pre-damaged building, but not less than the
reduced level seismic forces specified in Section 3403.5.1.1.3. New
structural members and connections required by this rehabilitation
design shall comply with the detailing provisions of the building
code for new buildings of similar structure, purpose, and location
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3403.5.2.3 Substantial structural damage to vertical load-carrying
components. Vertical load-carrying components that have sustained
substantial structural damage shall be rehabilitated to comply with
the applicable provisions for dead and live loads in the building
code. Undamaged vertical load-carrying components that receive dead
or live loads from rehabilitated components shall also be rehabilitated
to carry the design loads of the rehabilitation design. New structural
members and connections required by this rehabilitation design shall
comply with the detailing provisions of the building code for new
buildings of similar structure, purpose, and location.
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3403.5.2.3.1 Lateral force-resisting elements. Regardless
of the level of damage to vertical elements of the lateral force-resisting
system, if substantial structural damage to vertical load-carrying
components was caused primarily by wind or seismic effects, then the
building shall be evaluated in accordance with Section 3403.5.2.2.1
and, if non-compliant, rehabilitated in accordance with Section 3403.5.2.2.3.
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3403.5.2.4 Less than substantial structural damage. For damage less than substantial structural damage, repairs shall
be allowed that restore the building to its pre-damage state, using
materials and strengths that existed prior to the damage. New structural
members and connections used for this repair shall comply with the
detailing provisions of the building code for new buildings of similar
structure, purpose, and location.
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3403.5.3 Referenced Standards
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Standard Reference Number
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Title
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Referenced In Code Section Number
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ASCE 31-03
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Seismic Evaluation of Existing Buildings
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3403.5.1.1.1, TABLE 3403.5.1.1.2, 3403.5.1.1.3
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ASCE 41-06
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Seismic Rehabilitation of Existing Buildings
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3403.5.1.1.1,3403.5.1.1.2, TABLE 3403.5.1.1.2, 3403.5.1.1.3
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