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ORDINANCE NO. nC-265
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i ORDINANCE OF THE CITY OF SAN BERNARDINO ADDING CHAPTER 15.12
iTO THE SAN BERNARDINO MUNICIPAL CODE CONCERNING EARTHQUAKE HAZARD
IREDUCTION IN EXISTING BUILDINGS.
I THE MAYOR AND COMMON COUNCIL OF THE CITY OF SAN BERNARDINO DO
ORDAIN AS FOLLOWS:
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SECTION 1. Chapter 15.12 is added to the San Bernardino
7 Municipal Code to read as follows:
8 "Chapter 15.12
9 EARTHQUAKE HAZARD REDUCTION
10 IN EXISTING BUILDINGS
11
15.12.010 Purpose.
12 The purpose of this chapter is to promote public safety and
13 welfare by reducing the risk of death or injury that may result
14 from the effects of earthquakes on buildings with unreinforced
15 masonry bearing walls constructed before 1934. Such buildings
16 have been widely recognized as having sustained life-hazardous
17 damage, including partial or complete collapse, during past
18 moderate to strong earthquakes.
19 The provisions of this chapter are minimum standards for
20 structural seismic resistance, established primarily to reduce the
21 risk of death or injury, but will not necessarily prevent loss of
22 life, injury or earthquake damage to an existing building which
23 complies with these standards. This chapter shall not require
24 existing electrical, plumbing, mechanical or fire safety systems
25 to be altered unless they constitute a hazard to life or property.
26 This chapter provides systematic standards for classification
27 of buildings with unreinforced masonry bearing walls based on
28 their present or proposed use. priorities, standards and
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1 procedures are established under which certain buildings which are
2 vacant or unoccupied or are public nuisances shall be structurally
3 analyzed and anchored. Where the analysis determines
4 deficiencies, this chapter requires the building to be
5 strengthened. Owners of other buildings within the scope of this
6 chapter may voluntarily apply for approval to proceed under this
7 chapter.
8 Portions of the State Historical Building Code (SHBC)
9 established under Part 8, Title 24 of the California
10 Administrative Code are included in this chapter.
11 15.12.020 Scope.
12 The provisions of this chapter shall apply to buildings
13 constructed or under construction prior to January 1, 1934, or for
14 which a building permit was issued prior to January 1, 1934, which
15 on the effective date of this ordinance have unreinforced masonry
16 bearing walls as defined herein.
17 EXCEPTION: This chapter shall not apply to detached one or
18 two story single-family dwellings and detached apartment houses
19 containing less than five dwelling units and used solely for
20 residential purposes.
21 15.12.030 Definitions.
22 For purposes of this chapter, the applicable definitions in
23 the latest adopted edition of the Uniform Building Code
24 (hereinafter UBC), Chapter 23, including Section 2302, and the
25 following definitions shall apply:
26 A. Essential building. Any building housing a hospital or
27 other medical facility having surgery or emergency treatment
28 areas; fire or police stations; municipal government disaster
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1 operation and communication centers.
2 B. High risk building. Any building, not classified an
3 essential building, having an occupant load as determined by UBC
4 Section 3301{d) of one hundred occupants or more.
5 EXCEPTION: A high risk building shall not include any
6 building used for its intended purpose, as determined by the
7 Department of Building and Safety, for less than twenty hours per
8 week.
9 C. Historical Building. Any building designated as an
10 historical building by an appropriate federal, state or city
11 jurisdiction.
12 D. Low risk building. Any building, not classified an
13 essential building, having an occupant load as determined by UBC
14 Section 3301(d) of less than twenty occupants.
15 E. Medium risk building. Any building, not classified as a
16 high risk building or an essential building, having an occupant
17 load as determined by UBC Section 3301{d) of twenty occupants or
18 more.
19 F. Unreinforced masonry bearing wall. A masonry wall having
20 all of the following characteristics:
21 1. Provides the vertical support for a floor or roof.
22 2. The total superimposed load is over one hundred
23 pounds per linear foot.
24 3. The area of reinforcing steel is less than fifty
25 percent of that required by UBC Section 2418{j).
26 G. Conditional reconstruction permit. A permit to
27 reconstruct, granted by the Planning Commission, vlhich may impose
28 reasonabl<.: conditions to accommodate the intensity of the
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1 proposed use within the community. Such conditions may be less
2 than, but may not exceed those placed upon a newly established use
3 under a conditional use permit.
4
15.12.040 Rating classifications.
5
The rating classifications dB exhibited in Table No. 15.12-A
6 are hereby established and each applicable building within the
7 scope of this chclpter shall be placed in one such rating
8 classification by the Department of Duilding arw Safety. 'J.'he
9 total occupant load of the entire building as determined by UDC
10 Section 3301(dl shall be used to determine the rating
11 classification.
12
EXCEPTION: For the purpose of this chapter, portions of
13 buildings constructed to act independently \vhen resisting seismic
14 forces may be placed in separate rating classifications.
15 TABLE NU. 15.12-A
16 illlTING CLASSIFICATION
17
18
I Type of Building Classification
Essential Building I
High Risk Build ing II
Medium Risk Building III
Low Risk Build ing IV
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20
21
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15.12.050 General requlrements.
24
A. rl'he O\1ner of each builoing \lithin the sco2e of tilis chap-
25 ter which is Vlithin Classifications I, II, III and IV and has been
26 vacant or unoccupied for one hundred eighty days or which is a bui d-
27 ing declal-ed to be a public nuisance shall cause a structural anal
28 ysis to be made of Lhe building by a civil or "tructural ellyineer- r
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1 architect licensed by the State of California; and, if the
2 building does not meet the minimum earthquake standards specified
3 in this chapter, as shown in the structural analysis or as
4 determined by the Superintendent of the Building and Safety
5 Department, the owner shall obtain a conditional reconstruction
6 permit under the same procedures and requirements as provided in
7 Sections 19.78.040 through 19.78.070 and Section 19.78.110 hereof
8 and shall cause the building to be structurally altered to conform
9 to such standards and the conditions of the reconstruction permit;
10 or cause the building to be demolished or repaired under current
11 UBC building standards.
12 B. Any owner of a building within the scope of this chapter
13 may voluntarily cause such structural analysis to be made of the
14 building and obtain a conditional reconstruction permit, subject
15 to compliance with the same requirements and procedures applicable
16 to the owners of buildings who are required to comply with the
17 provisions of this chapter because their buildings are vacant or
18 unoccupied or are public nuisances.
19 C. The owner of a building within the scope of this chapter
20 shall comply with the requirements set forth above by submitting
21 to the Department of Building and Safety for review and approval a
22 structural analysis and plans for the proposed structural
23 alterations of the building necessary to comply with the minimum
24 requirements of this chapter or plans for the installation of wall
25 anchors in accordance with the requirements specified in Section
26 15.12.070 Subsection C. In the alternative, in the case of a
27 building declared to be a public nuisance, the owner may submit
28 plans for the immediate demolition or repair of the building under
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1 the current building standards of the UBC.
2 D. After plans are submitted and approved by the Department
3 of Building and Safety, the owner, after first obtaining the
4 conditional reconstruction permit, shall obtain a building permit.
5 E. The time, not to exceed six months, for submitting the
6 structural analysis and plans and for obtaining the building
7 permit shall be as granted by the Board of Building Commissioners
8 in the case of a building declared a public nuisance or by the
9 Planning Commission in other cases, or as granted by the l'layor and
10 Common Council on appeal in any case. The required construction
11 or demolition shall be completed within the time granted by the
12 Mayor and Common Council, Board of Building Commissioners, or the
13 Planning Commission, but shall not exceed one year after the
14 building permit is obtained. These time limits are subject to any
15 extensions granted by the Board of Building Commissioners or
16 Planning Commission, subject to an appeal to and final decision by
17 the Mayor and Common Council.
18 15.12.060 Historical buildings.
19 A. General. The standards and procedures established by
20 this chapter shall apply in all respects to an historical building
21 except that as a means to preserve original architectural elements
22 and facilitate restoration, an historical building may, in
23 addition, comply with the special provisions set forth in this
24 see tion.
25 B. Unburned clay masonry or adobe. Existing or re-erected
26 walls of adobe construction shall conform to the following:
27 1. Unreinforced adobe masonry wall shall not exceed a
28 height or length to thickness ratio of 5, for exterior bearing
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1 Nalls and must be provided with a reinforced bond beam at the top,
2 interconnecting all walls. Minimum beam depth shall be six inches
3 and a minimum width of eight inches less than the wall width.
4 Minimum wall thickness shall be eighteen inches for exterior
5 bearing walls and ten inches for adobe partitions. No adobe
6 structure shall exceed one story in height unless the historic
7 evidence indicates a two-story height. In such cases the height
8 to thickness ratio shall be the same as above for the first floor
9 based on the total two-story height and the second floor wall
10 thickness shall not exceed the ratio five by more than twenty
11 percent. Bond beams shall be provided at the roof and second
12 floor levels.
13 2. Foundation footings shall be reinforced concrete
14 under newly reconstructed walls and shall be fifty percent wider
15 than the wall above, soil conditions permitting, except that the
16 foundation wall may be four inches less in width than the wall
17 above if a rock, burned brick, or stabilized adobe facing is
18 necessary to provide authenticity.
19 3. New or existing unstabilized brick and adobe brick
20 masonry shall test to seventy-five percent of the compressive
21 strength as set forth in UBe Section 2405(b). Unstabilized brick
22 may be used where existing bricks are unstabilized and where the
23 building is not susceptible to flooding conditions or direct
24 exposure. Adobe may be allowed a maximum value of three pounds
25 per square inch for shear with no increase for lateral forces.
26 4. Mortar may be of the same soil composition and
27 stabilization as the brick in lieu of cement mortar.
28 5. Nominal tension stresses due to seismic forces normal
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to the wall may be neglected if the wall meets thickness
requirements and shear values allowed by this subsection.
C. Archaic materials. Allowable stresses for archaic
materials not specified in the UBC shall be based on
substantiating research data or engineering judgment subject to
the Department of Building and Safety's satisfaction.
D. Alternative materials and SHBC advisory review.
Alternative materials, design or methods of construction will be
considered as set forth in Section 15.12.080 Subsection D. In
addition, when a request for an alternative pro~osed design,
material or method of construction is being considered, the
Department of Building and Safety may file written request for
opinion to the State Historical Building Code Advisory Board for
its consideration, advice or findings.
15.12.070 Analysis and design.
A. General. Every structure within the scope of this
chapter shall be analyzed and constructed to resist minimum total
lateral seismic forces assumed to act noncurrently in the
direction of each of the main axes of the structure in accordance
with the following equation:
v = IKCSW
(15.12-1)
The value of IKCS need not exceed the values set forth in Table
No. 15.12-D based on the applicable rating classification of the
building.
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1
TABLE NO. 15.12-D
HORIZONTAL FORCE FACTORS
BASED ON RATING CLASSIFICATION
2
3
4
Rating Classification
IKCS
5
I
II
III and IV
0.186
0.133
0.100
6
7
8
B. Lateral forces on elements of structures. Parts or
9 portions of structures shall be analyzed and designed for lateral
10 loads in accordance ;,ith UBC Section 2312(d) but not less than the
11 value from the following equation:
12
F = IC SW
P P P
(15.12-2)
13 For the provisions of this subsection, the product of IS need
14 not exceed the values as set forth in Table No. 15.12-E.
15
EXCEPTION: Unreinforced masonry walls in buildings not
16 having a rating classification of I may be analyzed in accordance
17 with Section 15.12.090.
18
TABLE NO. 15.12-E
HORIZONTAL FORCE FACTORS "IS"
FOR PARTS OR PORTIONS OF STRUCTURES
19
20
21
Rating Classification
IS
22
I
II
III and IV
1 .50
1.00
0.75
23
24
25
C. Anchorage and interconnection. Anchorage and
26 interconnection of all parts, portions and elements of the
27 structure shall be analyzed and designed for lateral forces in
28
accordance with UBC Table 23-J and the equation F =IC SW as
p p p
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1 modified by Table No. 15.12-E. Minimum anchorage of masonry walls
2 to each floor or roof shall resist a minimum force of two hundred
3 pounds per linear foot acting normal to the wall at the level of
4 the floor or roof.
5 D. Level of required repair. Alterations and repairs
6 required to meet the provisions of this chapter shall comply with
7 all other applicable requirements of the UBC unless specifically
8 provided for in this chapter.
9 E. Required analysis.
10 1. General. Except as modified herein, the analysis and
11 design relating to the structural alteration of existing
12 structures within the scope of this chapter shall be in accordance
13 with the analysis specified in UBC Chapter 23.
14 2. Continuous stress path. A complete, continuous
15 stress path from every part or portion of the structure to the
16 ground shall be provided for the required horizontal forces.
17 3. positive connections. All parts, portions or
18 elements of the structure shall be interconnected by positive
19 means.
20 F. Analysis procedure.
21 1. General. Stresses in materials and existing
22 construction utilized to transfer seismic forces from the ground
23 to parts or portions of the structure shall conform to those
24 permitted by the UBe and those materials and types of construction
25 specified in Section 15.12.080. Nails may be used as part of an
26 approved connector.
27 2. Connections. Materials and connectors used for
28 interconnection of parts and portions of the structure shall
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1 conform to the UBC.
2 3. Unreinforced masonry walls. Unreinforced masonry
3 walls shall be analyzed as specified in UBC Section 2417 to
4 withstand all vertical loads as specified in UBC Chapter 23 in
5 addition to the seismic forces required by this chapter. Such
6 walls shall meet the minimum requirements set forth in UDC
7 sections 2418, 2419 and 2420. The fifty percent increase in the
8 seismic force factor for shear walls as specified in UBC Table No.
9 24-H may be omitted in the computation of seismic loads to
10 existing shear walls.
11 No allowable tension stress will be permitted in unreinforced
12 masonry walls. Walls not capable of resisting the required design
13 forces specified in this chapter shall be strengthened or shall be
14 removed and replaced.
15 EXCEPTIONS:
16 1. Unreinforced masonry walls in buildings not
17 classified as Rating I pursuant to Table No. 15.12-A may be
18 analyzed in accordance with Section 15.12.080.
19 2. Unreinforced masonry walls which carry no design
20 loads other than its own weight may be considered as veneer if
21 they are adequately anchored to new supporting elements.
22 G. Combination of vertical and seismic forces.
23 1. New materials. All new materials introduced into the
24 structure to meet the requirements of this section which are
25 subjected to combined vertical and horizontal forces shall comply
26 with applicable sections of the UBC Chapters 23, 24, 25 and 26.
27 2. Existing materials. When the stress in existing
28 lateral force resisting elem81ts are due to a combination of dead
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1 loads plus live loads plus seismic loads, the allowable working
2 stress specified in the UBC may be increased one hundred percent.
3 However, no increase will be permitted in the stresses allowed in
4 Section 15.12.080 and the stresses in members due only to seismic
5 and dead loads shall not exceed the values permitted by UBC
6 Section 2303(d).
7 3. Allowable reduction of bending stress by vertical
8 load. In calculating tensile fiber stress due to seismic forces
9 required by this chapter, the maximum tensile fiber stress may be
10 reduced by the full direct stress due to vertical dead loads.
11 15.12.080 Materials of construction.
12 A. General. All materials permitted by this Code including
13 their appropriate allowable stresses and those existing
14 configurations of materials specified herein may be utilized to
15 meet the requirements of this chapter.
16 B. Existing materials.
17 1. Unreinforced masonry walls. Unreinforced masonry
18 walls analyzed in accordance with this section may provide
19 vertical support for roof and floor construction and resistance to
20 lateral loads. The bonding of such walls shall be as specified in
21 UBC Section 24l2(b).
22 Tension stresses due to seismic forces normal to the wall may
23 be neglected if the wall does not exceed the height or length to
24 thickness ratio and the in-plane shear stresses due to seismic
25 loads as set forth in Table No. lS.12-F.
26 If the wall height-thickness ratio exceeds the specified
27 limits, the wall may be supported by vertical members designed by
28 the requirements of UBC Chapter 23. In addition, deflection of
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1
the supporting members at design loads shall not exceed one-tenth
2
of the wall thickness.
3
EXCEPTION: The wall may be supported by flexible vertical
4 bracing members designed in accordance with Section 15.12.070
5 Subsection B if the deflection at design loads is not less than
6 one-quarter nor more than one-third of the wall thickness.
7 The vertical supporting members shall be attached to the
8 floor and roof construction for their design loads independently
9 of the required wall anchors. Horizontal spacing of the vertical
10 members shall not exceed one-half the unsupported height of the
11 wall or ten feet maximum. However, the maximum horizontal
12 spacing of wall anchors at any anchorage level shall not exceed
13 that specified in Section 15.12.090 Subsection B 1.
14
TABLE NO. l5.l2.-F
ALLOWABLE VALUE OF UNREINFORCED
MASONRY WALLS WITH MINIMUM MORTAR(l)
15
16
17
Maximum Ratio
Unsupported Height
or Length to Thickness
Seismic In-Plane
Shear Stress
Based on Gross Area
Rating
Classification
18
19
I
II
III
IV
Not applicable (2)
9
10
12
Not applicable (2)
3 psi (3)
3 psi (3)
3 psi (3)
20
21
22 NOTES:
23
(1) Minimum quality mortar shall be determined by laboratory
24 testing in accordance with Section 15.12.080 Subsection E.
25
(2) Walls of buildings within rating classification I shall
26 be analyzed in accordance with Section 15.12.070 Subsection F.
27
(3) Allowable shear stress may be increased in accordance
28 with Section 15.12.080 Subsection G.
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The wall height may be measured vertically to bracing
2 elements other than a floor or roof. Spacing of the bracing
3 elements and wall anchors shall not exceed six feet. Bracing
4 elements shall be detailed to minimize the horizontal displacement
5 of the wall by components of vertical displacements of the floor
6 or roof.
7
2. Existing roof, floors, walls, footings, and wood
8 framing. Existing materials including wood shear walls utilized
9 in the described configuration may be used as part of the lateral
10 load resisting system, provided that the stresses in these
11 materials do not exceed the values shown in Table No. l5.l2-G.
12 TABLE NO. l5.l2-G
VALUES FOR EXISTING MATERIALS
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14
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15
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Materials or Configuration
of materials (1)
Allowable Values
Horizontal Diaphragms
a.
Roofs with straight sheathing 100 Ibs. per foot for
and roofing applied directly to seismic shear.
the sheathing.
Roofs with diagonal sheathing 400 Ibs. per foot for i
and roofing applied directly to seismic shear.
the sheathing. I
I
Floors with straight tongue and 150 Ibs. per foot for
groove sheathing. seismic shear.
Floors with straight sheathing 300 lbs. per foot for I
and finished wood flooring. seismic shear.
Floors with diagonal sheathing 450 Ibs. per foot for !
and finished wood flooring. seismic shear. i
b .
c.
d.
e.
Shear Walls
a. Wood stud walls with wood lath
and plaster.
50 Ibs. per foot each
side for seismic
shear.
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1
TABLE NO. 15.12-G (Cont.)
VALUES FOR EXISTING MATERIALS
2
3
4
Materials or Configuration
of materials (l)
Allowable Values
5
b .
Wood stud walls with plaster and
lath other than wood lath.
100 lbs. per foot each
side for seismic
shear.
6
7
3 .
f = 1,500 psi unless
Cotherwise shown by
tests.
Plain Concrete Footings
8
9
4.
Douglas Fir Wood (2)
Allowable stress same
as No.1 D.F.
10
ft = 18,000 psi per
square inch maximum
5.
Reinforcing Steel (2)
11
12
6.
Structural Steel (2)
ft = 20,000 lbs. per
square inch maximum
13
14
15
16 NOTES:
17
(1) Material must be sound and in good condition.
18
(2) Stress given may be increased for combinations of loads
19 as specified in Section 15.12.070 Subsection G 2.
C. Strengthening of existing materials. New materials
21 including wood shear walls may be utilized to strengthen portions
22 of the existing seismic resisting system in the described
23 configurations provided that the stresses do not exceed the values
24 shown in Table No. 15.12-H.
25
26
27
28
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I: 2.
12 I
,
13 I
,
14 I
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15 I
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16 i
17 I
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18 I
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19 I
20 I 3.
21 I
22 I
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24 I
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25 I 4.
26 I
27
28 1,1
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TABLE NO. 15.12-H
ALLOWABLE VALUES OF NEW MATERIALS USED
IN CONJUNCTION WITH EXISTING CONSTRUCTION
New Materials or
Configuration
of Materials
Horizontal 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.
I
Shear Walls
a.
Plywood sheathing applied
directly over existing wood
studs. No value shall be
given to plywood applied over
existing plaster or wood
sheathing.
b .
Dry wall or plaster applied
directly over existing wood
studs.
c .
Dry wall or plaster applied
to plywood sheathing over
existing wood studs.
Shear Bolts
Shear bolts and shear dowels
embedded a minimum of 8 inches
into unreinforced masonry walls.
Bolt centered in a 2 1/2 inch
diameter hole with dry-pack or
non-shrink grout around circum-
ference of bolt or dowel. (1)
Tension Bolts
Tension bolts and tension dowels
extending entirely through un-
reinforced masonry walls
secured with bearing plates on
far side of wall with at least
30 sq. inches of area. (2)
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Allowable Values
Same as specified in
UBC Table No. 25-J for
blocked diaphragms.
,
Same as values specified I
in UBC Table No. 25-J II
for shear walls. I
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75 percent of the values'l
specified in UBC Table I
No. 47-1. I
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33 1/3 percent of the
values specified in UBC
Table No. 47-1
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100 percent of the I
values for plain masonry'
specified in UBC Table
No. 24-G. No values
larger than those given I
for 3/4 inch bolts shall
be used. I
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1,200 Ibs. per bolt or
dowel.
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5
6
7
8
9
10
11
12
13
14
15
16
17
,
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19.
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10.
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TABLE NO. 15.12-H (Cont.)
ALLOWABLE VALUES OF NEW MATERIALS USED
IN CONJUNCTION WITH EXISTING CONSTRUCTION
New Materials or
Configuration
of Materials
5 .
Bolts extending to the exterior
face of the wall with a 2 1/2
inch round plate under the head.
Installed as specified for shear
bolts. Spaced not closer than
12 inches on center. (l) (2)
6.
Bolts or dowels extending to the
exterior face of the wall with
a 2 1/2 inch round plate under
the head and drilled at an
angle of 22 1/2 degrees to the
horizontal. Installed as
specified for shear bolts. (2)
7 .
Infilled Walls
Reinforced masonry infilled open-
ings in existing unreinforced
masonry wall with keys and dowels
to match reinforcing.
8. Reinforced Masonry
Masonry piers and walls
reinforced per UBC Section 2418.
Reinforced Concrete
Concrete footings, walls and
piers reinforced as specified
in UBC Chapter 26.
Existing Foundation Loads
Foundation loads for struc-
tures exhibiting no evidence of
settlement.
Allowable Values
I
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600 Ibs. per bolt.
1200 Ibs. per bolt
or dowel.
Same as values specifiedil
for unreinforced masonrYr
walls. i
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Same as values specifiedi
in UBC Table No. 21._B. i
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Same as values
in UBC Chapter
!
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specifiedr
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26. i
I
Calculated existing
foundation loads due
to maximum dead load
plus live load may be I
increased 25 percent fori
dead load, and may be I
increased 50 percent fOr'[
dead load plus seismic
load required by this I
Chapter. ,
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1 NOTES:
2 (1) Bolts and dowels shall be tested as specified in Section
3 15.12.080 Subsection F.
4 (2) Bolts and dowels shall be one-half inch minimum in
5 diameter.
6 D. Alternate materials. Alternate materials, designs and
7 methods of construction may be approved by the Department of
8 Building and Safety in accordance with the provisions of UBe
9 Section 105.
10 E. Minimum acceptable quality of existing unreinforced
11 masonry walls.
12 1. General provisions. All unreinforced masonry walls
13 utilized to carry vertical loads and seismic forces parallel and
14 !perpendicular to the wall plane shall be tested as specified in
15 this subsection. All masonry quality shall equal or exceed the
16 minimum standards established herein or shall be removed and
17 replaced by new materials. The quality of mortar in all masonry
18 walls shall be determined by performing in-place shear tests or by
19 testing eight inch diameter cores. Alternative methods of testing
20 may be approved by the Department of Building and Safety. Nothing
21 shall prevent pointing with mortar of all masonry wall joints
22 before the tests are first made. Prior to any pointing, the
23 mortar joints must be raked and cleaned to remove loose and
24 deteriorated mortar. Mortar for pointing shall be type S or N
25 except masonry cements shall not be used. All preparation and
26 mortar pointing shall be done under the continuous inspection of a
27 special inspector. At the conclusion of the inspection, the
28 inspector shall submit a written report to the licensed engineer
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1 or architect responsible for the seismic analysis of the building
2 setting forth the result of the work inspected. Such report shall
3 be submitted to the Department of Building and Safety for approval
4 as part of the structural analysis. All testing shall be
5 performed in accordance with the requirements specified in this
6 subsection by a testing agency approved by the Department of
7 Building and Safety. An accurate record of all such tests and
8 their location in the building shall be recorded and these results
9 shall be submitted to the Department of Building and Safety for
10 approval as part of the structural analysis.
11 2. Number and location of tests. The minimum number of
12 tests shall be two per wallar line of wall elements resisting a
13 common force, or one per one thousand five hundred square feet of
14 wall surface, with a minimum of eight tests in any case. The
15 exact test or core location shall be determined at the building
16 site by the licensed engineer or architect responsible for the
17 seismic analysis of the subject building.
18 3. In-place shear tests. The bed joints of the outer
19 wythe of the masonry shall be tested in shear by laterally
20 displacing a single brick relative to the adjacent bricks in the
21 wythe. The opposite head joint of the brick to be tested shall be
22 removed and cleaned prior to testing. The minimum quality mortar
23 in eighty percent of the shear tests shall not be less than the
24 total of thirty psi plus the axial stress in the wall at the point
25 of the test. The shear stress shall be based on the gross area of
26 both bed joints and shall be that at which movement of the brick
27 is first observed.
28 4. Core tests. A minimum number of mortar test
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1 Ispecimens equal to the number of required cores shall be prepared
2 from the cores and tested, as specified herein. The mortar joint
3 of the outer wythe of the masonry core shall be tested in shear by
4 placing the circular core section in a compression testing machine
5 with the mortar bed joint rotated fifteen degrees from the axis of
6 the applied load. The mortar joint tested in shear shall have an
7 average ultimate stress of twenty psi based on the gross area.
8 The average shall be obtained from the total number of cores made.
9 If test specimens cannot be made from cores taken then the shear
10 value shall be reported as zero.
11
F. Testing of shear bolts. One-fourth of all new shear
12 bolts and dowels embedded in unreinforced masonry walls shall be
13 tested by a special inspector using a torque calibrated wrench to
14 the following minimum torques:
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1/2" diameter bolts or dowels = 40 foot-lbs
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5/8" diameter bolts or dowels = 50 foot-lbs
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3/4" diameter bolts or dowels = 60 foot-lbs
18 No bolts exceeding three-quarter inch shall be used. All nuts
19 shall be installed over malleable iron or plate washers when
20 bearing on wood and heavy cut washers when bearing on steel.
21
G.
Determination of allowable stresses for design methods
22 based on test results.
23
1. Design shear values. Design seismic in-plane shear
24 stresses greater than permitted in Table No. 15.12-F shall be
25 substantiated by tests performed as specified in Section 15.12.080
26 Subsection E 3 and 4.
27 Design stresses shall be related to test results obtained in
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accordance with Table No. 15.12-1.
Intermediate values between
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1 three and ten psi may be interpolated.
2 TABLE NO. 15.12-1
ALLOWABLE SHEAR STRESS FOR TESTED UNRE1NFORCED MASONRY WALLS
3
4
Seismic ~lane
Shear Sasea ."n
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Gross Area
5
Eighty Percent
of Test Results in
psi Not Less Than
Average Test Results
of Cores in psi
6
7
30 plus axial stress
40 plus axial stress
50 plus axial stress
100 plus axial stress
or more
20 3 psi'
27 4 psi'
33 5 psi'
67 or more 10 psi max*
8
9
10
11
, Allowable shear stress may be increased by addition of
10 percent of the axial stress due to the weight of the
wall directly above.
12
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2. Design compression and tension values. Compression
14 stresses for unreinforced masonry having a minimum design shear
15 value of three psi shall not exceed one hundred psi. Design
16 tension values for unreinforced masonry shall not be permitted.
17
H. Five percent of the existing rod anchors utilized as all
18 or part of the required wall anchors shall be tested in pullout by
19 an approved testing laboratory. The minimum number tested shall
20 be four per floor and roof at walls with joists parallel to the
21 wall. The test apparatus shall be supported on the masonry wall
22 at a minimum distance of the wall thickness from the anchor
23 tested. The rod anchor shall be given a preload of three hundred
24 pounds prior to establishing a datum for recording elongation.
25 The tension test load reported shall be recorded at one-eighth
26 inch relative movement of the anchor and the adjacent masonry
27 surface. Results of all tests shall be reported. The report
28 shall include the test results as related to the wall thickness
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1 and joist orientation. The allowable resistance value of the
2 existing anchors shall be forty percent of the average of those
3 tested anchors having the same wall thickness and joist
4 orientation.
5
I. Qualification tests for devices used for wall anchorage
6 shall be tested with the entire tension load carried on the
7 enlarged head at the exterior face of the wall. Bond on the part
8 of the device between the enlarged head and the interior wall face
9 shall be eliminated for the qualification tests. The resistance
10 value assigned the device shall be twenty percent of the average
11 of the ultimate loads.
12
15.12.090 Information required on plans.
13
A. General. In addition to the seismic analysis required
14 elsewhere in this chapter, the licensed engineer or architect
15 responsible for the seismic analysis of the building shall
16 determine and record the information required by this section on
17 the approved plans.
18
B. Construction details. The following construction details
19 shall be made part of the approved plans:
20
1. All unrein forced masonry walls shall be anchored at
21 the roof level by tension bolts through the wall as specified in
22 Table No. lS.12-H, or by approved equivalent at a maximum anchor
23 spacing of six feet. Anchors installed in accordance with UBC
24
Section 203 shall be accepted as conforming to this requirement.
All unreinforced masonry walls shall be anchored at
all floors with tension bolts through the wall or by existing rod
anchors at a maximum anchor spacing of six feet. All existing rod
anchors shall be secured to the joists to develop the required
25
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1 forces. The Department may require testing to verify the adequacy
2 of the embedded ends of existing rod anchors. Tests when required
3 shall conform to Section 15.12.080 Subsection H.
4 When access to the exterior face of the masonry wall
5 is prevented by proximity of an existing building, wall anchors
6 conforming to Items 5 and 6 in Table 15.12-H may be used.
7 Alternative devices to be used in lieu of tension
8 bolts for masonry wall anchorage shall be tested as specified in
9 Section 15.12.080 Subsection I.
10 2. Diaphragm chord stresses of horizontal diaphragms
11 shall be developed in existing materials or by addition of new
12 materials.
13 3. Where trusses and beams other than rafters or joists
14 are supported on masonry, ledgers or columns shall be installed to
15 support vertical loads of the roof or floor members.
16 4. Parapets and exterior wall appendages not capable of
17 resisting the forces specified in this chapter shall be removed,
18 stabilized or braced to insure that the parapets and appendages
19 remain in their original position.
20 5. All deteriorated mortar joints in unreinforced
21 masonry walls shall be pointed with cement mortar. Prior to any
22 pointing, the wall surface must be sand or water blasted to remove
23 loose and deteriorated mortar. All preparation and pointing shall
24 be done under the continuous inspection of a special inspector
25 certified to inspect masonry or concrete. At the conclusion of
26 the project, the inspector shall submit a written report to the
27 Department of Building and Safety setting forth the portion of
28 work inspected.
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6. Repair details of 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 which were
performed in accordance with UBC Section 203.
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
unreinrorced masonry walls requiring repairs.
6. The type of interior wall surfaces and if
reinstalling or anchoring of ceiling plaster is necessary.
7. The general condition of the mortar joints and if the
joints need pointing."
I HEHEBY CERTIFY that the foregoing ordinance was duly
adopted by the Mayor and Common Council of the City of San
Bernardino at a
regular
meeting thereof, held on
the
4th
April
, 1983, by the following vote,
day of
to wit:
AYES:
Council Members r~st~npn~, RPilly
Hprnrinnp7.
.
llarks. OuiE" 1
Hnhh~ ~trirklor
NAYS:
None
ABSENT:
None
~~11A/~/
/ City Clerk
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The foregoing ordinance is hereby approved t '
~ day
of
April
, 1983.
Approved as to form:
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