HomeMy WebLinkAbout1916
ORDINANCE NO, 1916
AN ORDINANCE OF THE CITY OF ARCADIA APPROVING A TEXT
AMENDMENT TO ADD CHAPTER 9 TO THE BUILDING CODE
SETIING FORTH REGULATIONS FOR THE REDUCTION OF
EARTHQUAKE HAZARDS IN EXISTING BUILDINGS
o
WHEREAS, this text amendment was initiated by the City for the consideration of
adding to the Building Code Chapter 9 setting forth regulations for the reduction of
earthquake hazards in existing buildings,
WHEREAS, the City Council conducted a public hearing concerning the text
amendment on November 7, 1989 and approved the amendment.
WHEREAS, the City Council recognizes the danger posed by potentially hazardous
buildings in California and determines that it is appropriate to add Chapter 9 "Earthquake
Hazard Reduction in Existing Buildings" to the Arcadia Municipal Code in order to
promote public safety and welfare by reducing the risk of death or injury that may result
from the effects of earthquakes on unreinforced masonry bearing wall buildings
constructed prior to October 16,1938.
NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF ARCADIA DOES
HEREBY ORDAIN AS FOLLOWS:
Section 1, That Chapter 9 "Earthquake Hazard Reduction in Existing Buildings"
shall be added to Article VIII (Building Regulations) of the Arcadia Municipal Code as set
forth in attached Exhibit A.
Section 2, The City Clerk shall certify to the adoption of this Ordinance and shall
cause a copy of the same to be published in the official newspaper of said City within
fifteen (15) days after its adoption,
Passed, approved and adopted this 5th day of December 1989.
ATTEST:
-1-
1916
ST ATE OF CALIFORNIA )
COUNTY OF LOS ANGELES ) SS:
CITY OF ARCADIA )
I, JUNE 0, ALFORD, City Clerk of the City of Arcadia, hereby certify that the
foregoing Ordinance No, 1916 was passed and adopted by the City Council of the City of
Arcadia, signed by the Mayor and attested to by the City Clerk at a regular meeting of said
Council on the 5thdayof December 1989, and that said Ordinance was adopted by the
following vote, to wit:
AYES: Councilmember Gilb, Harbicht, Lojeski, Young and Chandler
NOES: None
ABSENT: None
-2-
1916
ARTICLE VIII
BUILDING REGULATIONS
CHAPTER 9
EARTIIQUAKE HAZARD REDUCTION IN
EXISTING BUILDINGS
Note: Code reference - 1985 Uniform Building Code (UBC)
8901. PURPOSE.
The purpose of this chapter is to promote public safety and welfare by
reducing the risk of death or injury that may result from the effects of
earthquakes on unreinforced masonry bearing wall buildings constructed
prior to October 16, 1938. Such buildings have been widely recognized for
sustaining life-hazardous damage, including partial or complete collapse
during moderate to strong earthquakes,
The provisions of this chapter are intended as minimum standards for
structural seismic resistance established primarily to reduce the risk of life
loss or injury, Compliance with these standards will not necessarily prevent
loss of life or injury or prevent earthquake damage to rehabilitated buildings.
This chapter does not require alteration of existing electrical, plumbing,
mechanical or fire safety systems unless they constitute a hazard to life or
property,
This chapter provides systematic procedures and standards for
identification and classification of unreinforced masonry bearing wall
buildings based on their present use. Priorities, time periods and standards
are also established under which these buildings are required to be
structurally analyzed and anchored, Where the analysis finds deficiencies,
this chapter requires the building to be strengthened or demolished,
Qualified Historical Buildings shall comply with the State Historical Building
Code (SHBC) established under Part 8, Tittle 24 of the California
Administrative Code,
8902, SCOPE,
The provisions of this chapter shall apply to all buildings constructed
or under construction prior to October 16, 1938, or for which a building permit
was issued prior to October 16, 1938, which on the effective date of this
ordinance have unreinforced masonry bearing walls as defined herein.
1
EXHIBIT A
EXCEPTION: This division shall not apply to detached one or two
family dwellings and detached apartment houses containing less than 5
dwelling units and used solely for residential purposes.
8903. DEFINmONS.
For purposes of this chapter, the applicable definitions in Sections 2302
and 2312 of the Uniform Building Code (UBC) shall apply:
ESSENTIAL BUILDING: Any building housing a hospital or other
medical facility having surgery or emergency treatment areas; fire or police
stations; municipal government disaster operations and communications
centers.
mGH RISK BUILDING: Any building, not classified an essential
building, having an occupant load of 100 or more, as determined by Section
3302 (a) of the Uniform Building Code.
EXCEPTION: A high risk building shall not include the following:
1. Any building having exterior walls braced with masonry cross walls
or wood frame crosswalls spaced less than 40 feet apart in each story.
Crosswalls shall be full story height with a minimum length of 1 1/2
times the story height.
2, Any building used for its intended purpose, as determined by the
building official, for less than 20 hours per week.
LOW RISK BUILDING: Any building, not classified as an essential
building, having an occupant load of less than 20 occupants as determined by
Section 3302 (a) of the Uniform Building Code.
MEDIUM RISK BUILDING: Any building, not classified as an essential
building, having an occupant load of 20 occupants or more as determined by
Section 3302(a) of the Uniform Building Code,
UNREINFORCED MASONRY BEARING WALL: A masonry wall
having all of the following characteristics:
1, Provides the vertical support for a floor or roof,
2. The total superimposed load is over 100 pounds per linear foot.
3, The area of reinforcing steel is less than 50 percent of that required
by Section 2407 (h) of the Uniform Building Code,
2
EXHIBIT A
8904. RATING CLASSIFICATIONS.
The rating classifications shown in Table No, 89-A are hereby
established and each building within the scope of this chapter shall be placed
in one such rating classification by the building official. The total occupant
load of the entire building as determined by Section 3302 (a) of the Uniform
Building Code shall be used to determine the rating classification.
EXCEPTION: For the purposes of this chapter, portions of buildings
constructed to act independently when resisting seismic forces may be
placed in separate rating classifications.
8905. GENERAL REQUIREMENTS.
The owner of each building within the scope of this chapter shall cause
a structural analysis of the building to be made by a civil or structural
engineer or architect licensed by the State of California. If the building does
not meet the minimum earthquake standards specified in this chapter, the
owner shall either cause it to be structurally altered to conform to such
standards; or cause the building to be demolished.
The owner of a building within the scope of this chapter shall comply
with the requirements set forth above by submitting to the building official
for review within the stated time limits:
(a), Within 270 days after the service of the order, a structural analysis,
which is subject to the approval by the building official, and which shall
demonstrate that the building meets the minimum requirements of this
chapter; or
(b), Within 270 days after the service of the order, the structural
analysis and plans for the proposed structural alterations of the building
necessary to comply with the minimum requirements of this chapter; or
(c). Within 120 days after service of the order, plans for the installation
of wall anchors in accordance with the requirements specified in Section 8907
(c) of this Chapter; or
(d). Within 270 days after the service of the order, plans for the
demolition of the building.
After plans are submitted and approved by the building official, the
owner shall obtain a building permit, commence and complete the required
construction or demolition within the time limits set forth in Table No, 89-B.
These time limits shall begin to run from the date the order is served in
accordance with Section 8906 (a) and (b) of this Chapter,
3
EXHIBIT A
Owners electing to comply with Subsection (c) of this section are also
required to comply with Subsections (b) or (d) of this section provided,
however, that the 270-day period provided for in such Subsections (b) and (d)
and the time limits for obtaining a building permit, commencing
construction and completing construction for complete structural alterations
or building demolition set forth in Table No, 89-B shall be extended in
accordance with Table No, 89-C. Each such extended time limit, except the
time for commencing construction shall begin to run from the date the order
is served in accordance with Section 8906 (b) of this Chapter, The time limit
for commencing construction shall commence from the date the building
permit is issued,
8906, ADMINISTRATION.
(a). Service of Order. The building official shall issue an order, as
provided in Section 8906 (b) of this Chapter, to the owner of each building
within the scope of this chapter in accordance with the minimum time
periods for service of such orders set forth in Table No, 89-C. The minimum
time period for the service of such orders shall be measured from the
effective date of Chapter 9. Upon receipt of a written request from the owner,
the building official shall order a building to comply prior to the normal
service date for such building set forth in this section.
(b). Contents of Order, The order shall be in writing and shall be
served either personally or by certified or registered mail upon the owner as
shown on the last equalized assessment, and upon the person, if any, in
apparent charge or control of the building, The order shall specify that the
building has been determined by the building official to be within the scope of
this chapter and, therefore, is required to meet the minimum seismic
standards of this chapter, The order shall specify the rating classification of
the building and shall be accompanied by a copy of Section 8905 which sets
forth the owner's alternatives and time limits for compliance,
(c), Appeal Form Order. The owner or person in charge or control of
the building may appeal to the City Council the building official's initial
determination that the building is within the scope of this chapter. Such
appeal shall be filed with the City Clerk within 60 days from the service date
of the order described in Section 8906 (b) of this Chapter. Any such appeal
shall be decided by the Council no later than 60 days after the date that the
appeal is filed, Such appeal shall be made in writing upon appropriate forms
provided therefore, by the building official and the grounds thereof shall be
stated clearly and concisely. Each appeal shall be accompanied by a filing fee
as set forth by resolution of the City Council.
4
EXHIBIT A
Appeals or requests for slight modifications from any other
determinations, orders or actions by the building official pursuant to this
chapter, shall be made in accordance with the normal appeal procedures
established in this code,
(d). Recordation, At the time that the aforementioned order is served,
the building official shall file with the office of the county recorder a
certificate stating that the subject building is within the scope of Chapter 8900 -
Earthquake Hazard Reduction in Existing Buildings. The certificate shall also
state that the owner thereof has been ordered to structurally analyze the
building and to structurally alter or demolish it where it is not found to
comply with Chapter 8900,
If the building is found not to be within the scope of this chapter, or as
a result of structural alterations or an analysis is found to be structurally
capable of resisting minimum seismic forces required by this chapter; or is
demolished; the building official shall file with the office of the county
recorder a certificate terminating the status of the subject building as being
classified within the scope of Chapter 8900 - Earthquake Hazard Reduction in
Existing Buildings,
(e), Enforcement. If the owner or other person in charge or control of
the subject building fails to comply with any order issued by the building
official pursuant to this chapter within any of the time limits set forth in
section 8805 of this Chapter, the building official shall order the entire
building vacated and remain vacated until such order has been complied
with, If compliance with such order has not been accomplished within 90
days after the date the building has been ordered vacated, or by such
additional time as may have been granted by the City Council, the building
official may order the demolition of the building in accordance with the
Abatement of Dangerous Buildings provisions of this code,
8907. ANALYSIS AND DESIGN.
(a). General. Every structure within the scope of this Division shall be
analyzed and constructed to resist minimum total lateral seismic forces
assumed to act nonconcurrently in the direction of each of the main axes of
the structure in accordance with the following equation:
V=ZIKCSW
The value of IKCS need not exceed the values set forth in Table No. 89-
D based on the applicable rating classification of the building.
(b), Lateral Forces on Elements of Structures, Parts or portions of
structures shall be analyzed and designed for lateral loads in accordance with
5
EXHIBIT A
Subsections 8907 (a) of this Chapter and 2312 (e) of the Uniform Building
Code but not less than the value from the following equation:
Fp=ZICp SWp
For the provisions of this subsection, the product of IS need not exceed
the values as set forth in Table No, 89-E,
Exception: Unreinforced masonry walls in buildings not having a
rating classification of I may be analyzed in accordance with Section
8908 of this Chapter,
The value of Cp need not exceed the values set forth in Table 89-F,
(c), Anchorage and Interconnection. Anchorage and interconnection
of all parts, portions and elements of the structure shall be analyzed and
designed for lateral forces in accordance with Table No, 89-F of this code and
the equation Fp=ZICpSWp as modified by Table No. 89-E. Minimum
anchorage of masonry walls to each floor or roof shall resist a minimum force
of 200 pounds per linear foot acting normal to the wall at the level of the floor
or roof.
(d), Level of Required Repair, Alterations and repairs required to meet
the provisions of this chapter shall comply with all other applicable
requirements of the Uniform Building Code unless otherwise specifically
provided for in this chapter.
(e), Required Analysis,
1, General. Except as modified herein, the analysis and design
relating to the structural alteration of existing structures within the
scope of this chapter shall be in accordance with the analysis specified
in Chapter 23 of the Uniform Building Code.
2. Continuous Stress Path. A complete, continuous stress path
from every part or portion of the structure to the ground shall be
provided for the required horizontal forces.
3. Positive Connections. All parts, portions or elements of the
structure shall be interconnected by positive means,
(f). Analysis Procedure,
1. General, Stress in materials and existing construction utilized
to transfer seismic forces from the ground to parts or portions of the
structure shall conform to those permitted by the Uniform Building
6
EXHIBIT A
Code and those materials and types of construction specified in Section
8908 of this Chapter,
2. Connections. Materials and connectors used for
interconnection of parts and portions of the structure shall conform to
the Uniform Building Code, Nails may be used as part of an approved
connector,
3. Unreinforced Masonry Walls, Except as modified herein,
unreinforced masonry walls shall be analyzed as specified in Section
2406, 2407 and 2408 of the Uniform Building Code to withstand all
vertical loads as specified in Chapter 23 of the Uniform Building Code
in addition to the seismic forces required by this chapter. The 50
percent increase in the seismic forces factor for shear walls as specified
in Section 2407 (h) 4F of the Uniform Building Code may be omitted in
the computation of seismic loads to existing shear walls.
No allowable tension stress will be permitted in unreinforced
masonry walls. Walls not capable of resisting the required design
forces specified in this chapter shall be strengthened or shall be
removed and replaced,
EXCEPTIONS:
1. Unreinforced masonry walls in buildings not classified as a
Rating Classification I pursuant to Table No, 89-A may be
analyzed in accordance with Section 8908 of this Chapter.
2, An unreinforced masonry wall which carries no design loads
other than its own free weight may be considered as veneer if it
is adequately anchored to new supporting elements,
(g), Combination of Vertical and Seismic Forces.
1. New Materials. All new materials introduced into the
structure to meet the requirements of this section which are subjected
to combined vertical and horizontal forces shall comply with section
2303 (0 of the Uniform Building Code.
2, Existing Materials, When stresses in existing lateral force
resisting elements are due to a combination of dead loads plus live
loads plus seismic loads, the allowable working stress specified in the
Uniform Building Code may be increased to 100 percent. However, no
increase will be permitted in the stresses aJlowed in Section 8908 of this
Chapter, and the stresses in members due only to seismic and dead
7
EXHIBIT A
loads shall not exceed the values permitted by Section 2303 (d) of the
Uniform Building Code,
3. Allowable Reduction of Bending Stress by Vertical Load, In
calculating tensile fiber stress due to seismic forces required by this
chapter, the maximum tensile fiber stress may be reduced by the full
direct stress due to vertical dead loads.
8908, MATERIALS OF CONSTRUCTION,
(a). General. All materials permitted by the Uniform Building Code
including their appropriate allowable stresses and those existing
configurations of materials specified herein may be utilized to meet the
requirements of this chapter,
(b), Existing Materials.
1. Unreinforced Masonry Walls, Unreinforced masonry walls
analyzed in accordance with this Section may provide vertical support
for roof and floor construction and resistance to lateral loads. The
facing and backing of such walls shall be bonded so that not less than 4
percent of the exposed face area is composed of solid headers extending
not less than 4 inches into the backing, The distance between adjacent
full-length headers shall not exceed 24 inches vertically or horizontally.
Where the backing consists of two or more wythes the header shall
extend not less than 4 inches into the most distant wythe, or the
backing wythes shall be bonded together with separate headers whose
area and spacing conform to the foregoing.
Tension stresses due to seismic forces normal to the wall may be
neglected if the walls do not exceed the height to thickness ratio in
Table No, 89-G and the in-plane shear stresses due to seismic loads as
set forth in Table No, 89-J.
If the wall height-thickness ratio exceeds the specified limits, the
wall may be supported by vertical bracing members designed in
accordance with Section 8907 of this Chapter. The deflection of such
bracing member at design loads shall not exceed one-tenth of the wall
thickness,
EXCEPTION: The wall may be supported by flexible vertical
bracing members designed in accordance with Section 8907 (b) of
this Chapter if the deflection at design loads is not less than one-
quarter nor more than one-third of the wall thickness.
8
EXHIBIT A
All vertical bracing members shall be attached to floor and roof
construction for their design loads independently of required wall
anchors, Horizontal spacing of vertical bracing members shall not
exceed one-half the unsupported height of the wall nor ten feet.
The wall height may be measured vertically to bracing elements
other than a floor or roof, Spacing of the bracing elements and wall
anchors shall not exceed six feet. Bracing elements shall be detailed to
minimize the horizontal displacement of the wall by components of
vertical displacements of the floor or roof.
2. Existing Roof, Floors, Walls, Footings, and Wood Framing.
Existing materials including wood shear walls utilized in the described
configuration may be used as part of the lateral load resisting system,
provided that the stresses in these materials do not exceed the values
shown in Table No, 89-H.
(c). Strengthening of Existing Materials. New materials including
wood shear walls may be utilized to strengthen portions of the existing
seismic resisting system in the described configurations provided that the
stresses do not exceed the values shown in Table 89-1.
(d). Alternate Materials, Alternate materials, designs and methods of
construction may be approved by the building official in accordance with the
provisions of the Uniform Building Code.
(e). Minimum Acceptable Quality of Existing Unreinforced Masonry
Walls.
1, General Provisions. All unreinforced masonry walls utilized
to carry vertical loads and seismic forces parallel and perpendicular to
the wall plane shall be tested as specified in this subsection, All
masonry quality shall equal or exceed the minimum standards
established herein or shall be removed and replaced by new materials,
Alternate methods of testing may be approved by the building official.
The quality of mortar in all masonry walls shall be determined by
performing in-place shear tests or by testing eight inch diameter cores.
Alternative methods of testing may be approved by the building
official. Nothing shall prevent pointing with mortar of all the
masonry wall joints before the tests are first made. Prior to any
pointing, the mortar joints must be raked and cleaned to remove loose
and deteriorated mortar, Mortar for pointing shall be Type 5 or N
except that masonry cements shall not be used, All preparations and
mortar pointing shall be done under the continuous inspection of a
Registered Deputy Building Inspector. At the conclusion of the
inspection, the inspector shall submit a written report to the licensed
9
EXHIBIT' :A
engineer or architect responsible for the seismic analysis of the building
setting forth the result of the work inspected, Such report shall be
submitted to the building official for approval as part of the structural
analysis, All testing shall be performed in accordance with the
requirements specified in this subsection by a testing agency approved
by the building official, An accurate record shall be kept of all such tests
and of their locations in the building, and these results shall be
submitted to the building official for approval as part of the structural
analysis,
2, Number and Location of Tests. The minimum number of
tests shall be two per wall or line wall elements resisting a common
force, or 1 per 1500 square feet of wall surface, with a minimum of eight
tests in any case, The exact test or core location shall be determined at
the building site by the licensed engineer or architect responsible for
the seismic analysis of the subject building,
3, In-Place Shear Tests, The bed joints of the outer wythe of the
masonry shall be tested in shear by laterally displacing a single brick
relative to the adjacent bricks in that wythe, The opposite head joint of
the brick to be tested shall be removed and cleaned prior to testing, The
minimum quality mortar in 80 percent of the shear test shall not be
less than the total of 30 psi plus the axial stress in the wall at the point
of the test. The shear stress shall be based on the gross area of both bed
joints and shall be that at which movement of the brick is first
observed,
4, Core Tests. A minimum number of mortar test specimens
equal to the number of required cores shall be prepared from the cores
and tested as specified herein, The mortar joint of the outer wythe of
the masonry core shall be tested in shear by placing the circular core
section in a compression testing machine with the mortar bed joint
rotated 15 degrees from the axis of the applied load. The mortar joint
tested in shear shall have an average ultimate stress of 20 psi based on
the gross area. The average shall be obtained from the total number of
cores made. If the test specimens cannot be made from cores taken,
then the shear value shall be reported as zero.
(f). Testing of Shear Bolts. One-fourth of all new shear bolts and
dowels embedded in unreinforced masonry walls shall be tested by Special
Inspector using a torque calibrated wrench to the following minimum
torques:
1/2" diameter bolts or dowels = 40 foot-lbs,
5/8" diameter bolts or dowels = 50 foot-lbs.
3/4" diameter bolts or dowels = 60 foot-lbs,
10
EXHIBIT A
No bolts exceeding 3/4" shall be used. All nuts shall be installed over
malleable iron or plate washers when bearing on wood and heavy cut
washers when bearing on steel.
(g). Determination of Allowable Stresses for Design Methods Based on
Test Results.
1. Design Shear Values, Design seismic in-plane shear stresses
shall be substantiated by tests performed as specified in Section 8908 (e)
3 and 4 of this Chapter.
Design stresses shall be related to test results obtained in
accordance with Table No. 89-J, Intermediate values between 3 and 10
psi may be interpolated,
2, Design Compression and Tension Values, Compression
stresses for unreinforced masonry having a minimum design shear
value of 3 psi shall not exceed 100 psi. Design tension values for
unreinforced masonry shall not be permitted,
(h), Five percent of the existing rod anchors utilized as all or part of the
required wall anchors shall be tested in pullout by an approved testing
laboratory. The minimum number tested shall be four per floor, with two
tests at walls with joists framing into the wall and two tests at walls with
joists parallel to the wall. The test apparatus shall be supported on the
masonry wall at a minimum distance of the wall thickness from the anchor
tested, The rod anchor shall be given a preload of 300 lbs. prior to establishing
a datum for recording elongation. The tension test load reported shall be
recorded at one-eighth inch relative movement of the anchor and the
adjacent masonry surface. Results of all tests shall be reported. The report
shall include the test results as related to the wall thickness and joint
orientation. The allowable resistance value of the existing anchors shall be 40
percent of the average of those tested anchors having the same wall thickness
and joint orientation.
(I), Qualification tests for devices used for wall anchorage shall be
tested with the entire tension load carried on the enlarged head at the exterior
face of the wall. Bond on the part of the device between the enlarged head
and the interior wall face shall be eliminated for the qualification test. The
resistance value assigned the device shall be 20 percent of the average of the
ultimate loads.
8909. INFORMATION REQUIRED ON PLANS,
11
EXHIBIT A
(a). General. In addition to the seismic analysis required elsewhere in
this Chapter, the licensed engineer or architect responsible for the seismic
analysis of the building shall determine and record the information required
by this Section on the approved plans.
(b). Construction Details, The following requirements with approved
construction details shall be made part of the approved plans,;
1. All unreinforced masonry walls shall be anchored at the roof
level by tension bolts through the walls as specified in Table No, 89-1,
or by approved equivalent at a maximum anchor spacing of six feet,
All unreinforced masonry walls shall be anchored at all floors
with tension bolts through the wall or by existing rod anchors at the
maximum anchor spacing of six feet, All existing rod anchors shall be
secured to the joists to develop the required forces, The building
official may require testing to verify the adequacy of the embedded ends
of existing rod anchors. Tests when required shall conform to Section
8908 (h) of this Chapter,
When access to the exterior face of the masonry wall is
prevented by proximity of an existing building, wall anchors
conforming to Items 5 and 6 in Table 89-1 may be used.
Alternative devices to be used in lieu of tension bolts for
masonry wall anchorage shall be tested as specified in Section 8908 (i) of
this Chapter.
2. Diaphragm chord stresses of horizontal diaphragms shall be
developed in existing materials or by addition of new materials.
3. Where trusses and beams other than rafters or joists are
supported on masonry, ledgers or columns shall be installed to support
vertical loads of the roof or floor members.
4. Parapets and exterior wall appendages not capable of resisting
the forces specified in this chapter shall be removed, stabilized or
braced to insure that the parapets and appendages remain in their
original position.
5, All deteriorated mortar joints in unreinforced masonry walls
shall be pointed with Type S or N mortar (Masonry cements shall not
be used). Prior to any pointing, the wall surface must be raked and
cleaned to remove loose and deteriorated mortar, All preparation and
pointing shall be done under the continuous inspection of a special
inspector certified to inspect masonry or concrete, At the conclusion of
12
EXHIBIT A
the project, the inspector shall submit a written report to the building
official setting forth the portion of the work inspected,
6. Repair details shall be prepared for any cracked or damaged
unreinforced masonry wall required to resist forces specified in this
chapter.
(c), Existing Construction. The following existing construction
information shall be made part of the approved plans,:
1. The type and dimensions of existing walls and the size and
spacing of floor and roof members.
2. The extent and type of existing wall anchorage to floors and
roof,
3. The extent and type of parapet corrections, if any, which were
performed in accordance with the Uniform Building Code,
4, Accurately dimensioned floor plans and masonry wall
elevations showing dimensioned openings, piers, wall thickness and
heights,
5. The location of cracks or damaged portions of unreinforced
masonry walls requiring repairs,
6, The type of interior wall surfaces and whether reinstalling or
anchoring of ceiling plaster is necessary.
7. The general condition of the mortar joints and whether the
joints need pointing.
13
EXHIBIT A
TABLE NO, 89-A
RATING CLASSIFICATIONS
TYPE OF BUILDING
CLASSIFICATION
Essential Building
High Risk Building
Medium Risk Building
Low Risk Building
I
II
ill
IV
TABLE NO, 89-B
TIME UMITS FOR COMPLIANCE (1)
REQUIRED AarON OBTAIN BUILDING COMMENCE CaNST COMPLETE CaNST,
AarON BY PERMIT wrTHIN WITHrN WlTHrN
ONNER
Comprete structural 1 year 180 days (2) 3 years
Alterations or
Building Demolition
Wall Anchor 180 days 270 days 1 year
Installation
(1) Where two or more buildings under separate ownership are to be rehabilitated
simultaneousry, an extension can be based on the average time requirements for the buildings
invorved, with a suggested minimum extension of 6 months. An extension could be granted on
submission of a binding agreement between the owners involved, with the actuar date of
compliance to be determined by the building official.
(2) Measured from date of building permit issuance. All other time limits are measured from
the date of the order.
14
EXHIBIT A
TABLE NO, 89-C
SERVICE PRIORITIES AND
EXTENDED TIME PROVISIONS
Rating Occupant Extension of Time
Classification Load if Wall Anchors
are Installed
r Any 1 year
(Highest Priority)
II 100 or more 3 years
1lI 100 or more 5 years
51 to and 6 years
including 99
20 to and 6 years
including 50
rv Less than 20 7 years
(Lowest Priority)
Minimum Time
Periods for
Service of Order
o
90 days
1 year
2 years
3 years
4 years
TABLE NO, 89-D
HORIZONTAL FORCE FACTORS BASED
ON RATING CLASSIFICATION
RATING
CLASSIFICATION
IKCS
I
IT
Ill&IV
0.186
0.133
0.100
15
EXHIBIT A
TABLE NO. 89-E
HORIZONTAL FORCE FACTORS "IS"
FOR PARTS OR PORTIONS OF STRUCTURES
RATING
CLASSIFICATION
IS
I
II
III&IV
1.50
1,00
0,75
16
EXHIBIT A
TABLE NO. 89-F
HORIZONTAL FORCE FACTOR "Cp" FOR PARTS OR
PORTIONS OF BUILDINGS OR OTHER STRUCTURES (1)
Part or Portion of
Buildinj?,S
Di rection
of Force
Varue
ofCp
Exterior bearing and non-bearing walls,
interior bearing walls and partitions,
interior non-bearing walls and
partitions over ten feet in height,
masonry fences over six feet in height.
Normal to
Flat Surface 0,20
Normal to
Flat Surface 1.00
Any
Direction 1.00
Cantilever parapet and other cantilever
walls, except retaining walls,
Exterior and interior ornamentations
and appendages
When connected to or a part of a
building; towers, tanks, towers and
tanks plus contents, racks over 8 feet
3 inches in height prus contents,
chimneys, smokestacks, and penthouses.
Any
Direction
0.20 (2, 4)
When connected to or a part of a
building: Rigid and rigidly mounted
equipment and machinery not required
for continued operation of essential
occupancies. (5)
Any
Horizontal
Direction
0.20 (3)
Tank plus effective contents resting
on the ground.
Any
Direction
0.12
Floors and roofs acting as
diaphragms.
In the plane of
the diaphragm
0,]2 (6)
Prefabricated structural elements,
other than walls, with force applied
at center of gravity of assembly,
Any
Horizontal
Direction
0.30
Connections for exterior panels or
erements.
Any
Direction
2.00
(1) See Section 8907 (b)for use of Cpo
(2 When located in the upper portion of any building with a h /D ratio of 5 to 1 or greater the
value shall be increased by 50%.
(3) For flexible and flexibility mounted equipment and machinery, the appropriate values for
Cp shall be determined with consideration given to both the dynamic properties of the
equipment and machinery and to the building or structure in which it is places.
17
EXHIBIT A
(4) The Wp for storage racks shall be the weight of the racks plus contents. The value of Cp for
racks over two storage support levels in height shall be 0.16 for the levels below the top
two levels.
(5) The design of the equipment and machinery and their anchorage is an integral part of the
design and specification of such equipment and machinery. The structure to which the
equipment or machinery is mounted shall be capable of resisting the anchorage forces (see
also Section 2312 (k) of the Uniform Building Code.
(6) Floor and roofs acting as diaphragms shall be designed for a minimum force resulting from a
Cp of 0.12 applied to Wp unless a greater force results from the distribution of lateral forces
in accordance with Section 2312 (e) of the Uniform Building Code.
18
EXHIBIT A
TABLE NO, 89-G
ALLOWABLE VALUE OF HEIGHT-THICKNESS RATIO
OF UNREINFORCED MASONRY WALLS WITH MINIMUM
QUALITY MORTAR. (1) (2)
BUILDING WITH CROSSW ALLS AS ALL OTHER
DEFINED BY SECTION 8903 BUILDINGS
Walls of
One Story Buildings 16 13
First Story Wall of
Multi-Story Buildings 16 15
Walls in Top Story of
Multi-Story Buildings 14 9
All Other Walls 16 13
(1) Minimum quality mortar shall be determined by laboratory testing in accordance with
Section 8908 (e) of this Chapter
(2) Table 89-G is not applicable to buildings of rating classification l. Walls of buildings
within rating classification r shall be analyzed in accordance with Section 8907 (0 of this
Chapter.
19
EXHIBIT A
TABLE NO, 89-H
V ALVES FOR EXISTING MATERIALS
EXISTING MATERIALS OR
CDNflGURA nON OFMA TERIALS (1)
ALLOWABLE VALUES
1. HORIZONTAL DIAPHRAGMS
a, Roofs with straight sheathing
and roofing applied directly to
the sheathing.
100 Ibs. per foot for seismic
shear,
b. Roofs with diagonal sheathing
and roofing applied directly to
the sheathing.
400 Ibs, per foot for seismic
shear.
c. floors with straight tongue and
groove sheathing,
150 Ibs. per foot for seismic
shear.
d, floors with straight sheathing
and finished wood flooring.
300 Ibs. per foot for seismic
shear.
e. floors with diagonal sheathing
and finished flooring.
450 Ibs. per foot for seismic
shear.
f. floors or roofs with straight
sheathing and plaster applied to
the joist or rafters. (2)
Add 50 Ibs, per foot to the
allowable values for items
la and lc,
2, SHEAR WALLS
Wood stud walls with lath and plaster, 100 Ibs, per foot each side for
seismic shear.
3, PLAIN CONCRETE FOOTINGS f'c = 1500 psi unless otherwise
shown by tests.
4. OOUGLAS FIR WOOD Allowable stress same as No. 1
D.F. (3)
5. REINFORCING STEEL ft = 18,000 Ibs, per square inch
maximum. (3)
6. STRUCTURAL STEEL ft = 20,000 Ibs, per square inch
maximum. (3)
(1) Material must be sound and in good condition.
(2) The wood lath and praster must be reattached to existing joists or rafters in a manner
approved by the Department.
(3) Stresses given may be increased for combinations of loads as specified in Section 8907 (g)2.
20
EXHIBIT A
TABLE NO. 89-1
ALLOWABLE VALUES OF NEW MATERIALS USED
IN CONJUNCTION WITH EXISTING CONSTRUCTION (1)
NEW MATERIALS OR
CONAGURATION OFMATERIAI5
ALLOWABLE VALUES
1. HORlZONT AL DIAPHRAGMS
Plywood sheathing applied directly over
existing straight sheathing with ends of
plywood sheets bearing on joists or rafters
and edges of plywood located on center of
individual sheathing boards,
2. SHEAR WALLS
a, prywood sheathing applied directly over
existing wood studs. No value shall be
given to plywood applied over existing
plaster or wood sheathing.b
b. Dry wall Or plaster applied directly over
existing wood studs,
c. Dry wall Or plaster applied to plywood
sheathing over existing wood studs,
3, SHEAR BOLTS
Shear bolts and shear dowels embedded a
minimum of 8 inches into unreinforced
masonry walls, Bolt centered in a 21/2 inch
diameter hole with dry-pack or non-shrink
grout around circumference of bolt or
dowel. (1) shall be used.
4, TENSION BOLTS
Tension bolls and tension dowels extending
entirely through unreinforced masonry walls
secured with bearing plates on far side of wall
with at least 30 square inches of area, (2)
5. WALL ANCHORS (8909 (b) 1.)
a. Bolls extending to the exterior face of the
wall with a 2 1/2 inch round plate under
the head. rnstalled as specified for shear
bolts, Spaced not doser than 12 inches on
centers. (1) (2)
21
Same as specified in Table No 25-J
of the Uniform Building Code for
blocked diaphragms,
Same as varues specified in Tabre
No, 25-K of the Uniform Building
Code for shear walls,
75 percent of the values specified in
Table No. 47-1 of the Uniform
Building Code.
33 1/3 percent of the values
specified in Tabre No. 47-1 of the
Uniform Building Code.
100 percent of the values for solid
masonry specified in Table No,
24-E of the Uniform Building
Code. No values rarger than
those given for 3/4 inch bolts
1200 lbs. per bolt or dowel.
600 lbs. per boll.
EXHIBIT A
b, Bolts or dowels extending to the exterior
face of the wall with a 21/2 inch round
plate under the head and drill at an angle
of 22 1/2 degrees to the horizontal.
Installed as specified for shear bolts, (1) (2)
6. INFlLLED WALLS
Reinforced masonry infilled openings in
existing unreinforced masonry walls with
keys or dowers to match reinforcing.
7. REINFORCED MASONRY
Masonry piers and walls reinforced per
Section 2407 of the Uniform Building Code,
8. REINFORCED CONCRETE
Concrete footings, walls and piers reinforced
as specified in Division 26 of the Uniform
Building Code and designed for tributary
loads.
9. EXISTING FOUNDATION LOADS
Foundation loads for structures exhibiting no
evidence of settlement.
1200 rbs. per bolt or dowel.
Same as values specified for
unreinforced masonry walls,
Same varues as specified in
Division 26 of the Uniform
Building Code,
Same values as specified in
Division 26 of the Uniform
Code,
Calculated existing foundation
loads due to maximum dead load
plus live load may be increased 25
percent for dead load, and may be
increased 50 percent for dead load
plus seismic load required by this
Division.
(1) Bolts and dowels to be tested as specified in Section 8908 (I), of this Chapter.
(2) Bolts and dowers to be 1/2 inch minimum in diameter.
22
EXHIBIT A
TABLE NO, 89-J
ALLOWABLE SHEAR STRESS FOR TESTED
UNREINFORCED MASONRY WALLS
Eighty percent of
test results in psi
not less than
Average test results
of cores in psi
Seismic in-prane
shear based on
gross area (t)
30 plus axial stress
40 plus axial stress
50 prus axiar stress
100 plus axial stress or more
20
27
33
67 or more
3 psi
4 psi
5 psi
10 psi max
(1) Allowabre shear stress may be increased by addition of 10 percent of the axial stress due to
the weight of the wall directly above,
23
EXHIBIT A
C =
Cp =
D =
f'c =
Fp =
ft =
hn =
I =
S =
v =
w =
Wp =
Z
=
GLOSSARY OF SYMBOLS AND NOTATIONS
Numerical coefficient as specified in Section 2312 (d) of the
Uniform Building Code,
Numerical coefficient as specified in Section 2312 (g) of the
Uniform Building Code,
The dimension of the structure, in feet, in a direction parallel to
the applied forces.
Specified compressive strength of concrete, psi
Lateral forces on a part of the structure and in the direction
under consideration
Allowable tensile stress, psi
Height in feet above the base to level n
Occupancy Importance Factor as set forth in Table No. 23-K of
the Uniform Building Code
Numerical coefficient for site-structure resonance
The total lateral force or shear at the base
The total dead load as defined in Section 2302 of the Uniform
Building Code including the partition loading specified in
Section 2304 (d) of the Uniform Building Code where applicable
The weight of a portion of a structure or nonstructural
component
Numerical coefficient dependent upon the zone as determined
by Figure No, 1, of Chapter 23 of the Uniform Building Code,
All areas in California are classified in Zones 3 or 4, For
locations in Zone No.3, Z = 3/4. For locations in Zone No, 4,
Z=1
24
EXHIBIT A