AC70-1012-R1
#12
AC70-1012-R1
#12
AC70-1012-R1
September 11, 2012 Mr. Brian Gerber Ms. Elyse Levy International Code Council Evaluation Service (ICC‐ES) 5360 Workman Mill Road Whittier, CA 90601‐2256 RE: Agenda item 12: Acceptance Criteria AC70 Dear Mr. Gerber and Ms. Levy, I am writing concerning the proposed paragraph to be added to section 6.0 on “Interior, Nonstructural Walls.” The transverse pressure for this application should be 10 PSF at a minimum, and even include an exception up to 15 PSF for specific applications. The American Iron and Steel Institute (AISI) has included this 10 PSF limit in both AISI S200, and the new AISI S220‐11 North American Standard for Cold‐Formed Steel Framing – Nonstructural Members. I was involved in the discussions leading up to both limits, and provide the following points:  Part of the committee concern was to exclude the exterior building envelope from the applicability of nonstructural partitions. Therefore, wording was added to AISI S220 to exclude “the gravity load resisting system, lateral force resisting system, or building envelope.” This is part of the definition of “nonstructural member.”  There was a concern that allowing pressures greater than 10 PSF would permit these members and systems to be used to resist wind loads. The above exclusion prohibits that usage.  Furthermore, the AISI S220 document permits an exception for pressurized air plenums, ceilings, and elevator shaft enclosures, with allowable design pressures up to 15 PSF. With respect to section 13.5.8 of ASCE 7‐10, this could be referenced in this section, but should not be used to justify a 5 PSF pressure limitation. Seismic loads are definitely not pressures: seismic loads must be considered in multiple directions other than just transverse. Section 13.5.8 includes exceptions that are not stated in the proposed paragraph. A revised proposed paragraph is included as an attachment, along with referenced sections from AISI S220 and ASCE 7‐10. Sincerely, DSi ENGINEERING, LLC Don Allen, P.E. Senior Engineer enclosure 5550 Triangle Parkway Suite 100 Norcross, Ga. 30092
Phone: 770-409-4487
Fax: 770-242-6305
AC70-1012-R1
Attachment 1
Proposed rewording of paragraph to be added to section 6.0 of AC70, that would appear in the design section of evaluation reports: Interior, Nonstructural Walls: For interior, nonstructural walls that are not subject
to sustained tension loads, the power-driven fasteners described in Section # may be
used to attach steel track to concrete or steel in all Seismic Design Categories,
provided substantiating data or calculations are submitted addressing the connection
capacity. Track and stud members supported by these power-driven fasteners must
qualify as nonstructural members in accordance with the nonstructural member
definition and scope statement in AISI S220. In addition, limitations in section 13.5.8
of ASCE 7-10 shall be considered. The design load on the fastener must not exceed
the allowable load shown in Tables #, # and #, as applicable.
For reference:
Applicable portion of AISI S220 scope statement: This standard applies to nonstructural members that comply with the following:
1) Member is in a steel-framed system that is limited to a transverse (out-of-plane) load of not more than
2
10 lb/ft (0.48 kPa).
Exception: Pressurized air plenums, ceilings and elevator shaft enclosures are permitted to have a
2
load of not more than 15 lb/ft (0.72 kPa).
2) Member is in a steel-framed system that is limited to a superimposed axial load, exclusive of
sheathing materials, of not more than 100 lb/ft (1.46 kN/m).
3) Member is limited to a superimposed axial load of not more than 200 lbs (0.89 kN).
AISI S220 definition of nonstructural member: Nonstructural Member. A member in a steel‐framed system that is not a part of the gravity load resisting system, lateral force resisting system or building envelope. ASCE 7­10 section 13.5.8, with exception: 13.5.8 Partitions
13.5.8.1 General
Partitions that are tied to the ceiling and all partitions greater than 6 ft (1.8 m) in height shall be laterally braced to the
building structure. Such bracing shall be independent of any ceiling lateral force bracing. Bracing shall be spaced to limit
horizontal deflection at the partition head to be compatible with ceiling deflection requirements as determined in Section
13.5.6 for suspended ceilings and elsewhere in this section for other systems.
EXCEPTION: Partitions that meet all of the following conditions:
1. The partition height does not exceed 9 ft (2,740 mm).
2. The linear weight of the partition does not exceed the product of 10 lb (0.479 kN) times the height (ft or m) of
the partition.
3. The partition horizontal seismic load does not exceed 5 psf (0.24 kN/m2).
13.5.8.2 Glass
Glass in glazed partitions shall be designed and installed in accordance with Section 13.5.9.
5550 Triangle Parkway Suite 100 Norcross, Ga. 30092
Phone: 770-409-4487
Fax: 770-242-6305
AC70-1012-R1
Subject: Comments on Proposed Revisions to ICC-ES AC70
#12
September 11, 2012
Dear Mr. Gerber,
Hilti is offering the following public comments on your letter dated August 21st, 2012 regarding proposed
revisions to ICC-ES AC70 Acceptance Criteria for Power-Driven Fasteners in Concrete, Steel and Masonry
Elements.
In reference to Item 8 in your letter, Hilti does not believe that a 5 psf limitation should be placed on the
transverse load of the partition wall. We believe that this is an incorrect and overly conservative
interpretation of the code. Instead, AC70 and the ESRs should simply point the Design Professionals and
Building Officials to the relevant code sections for the particular application. We feel that since
engineering calculations are required to be submitted to the Building Official, the Design Professional
should use their judgment as to what type of fastening system to use and justify that use through
calculations that are submitted to the Building Official for the project.
Our proposed alternative language is as follows:
Interior Walls and Partitions: For interior walls and partitions that are not subject to sustained tension
loads, the power driven fasteners described in Section 3.1 may be used to attach steel track to concrete or
steel in all Seismic Design Categories, where the design is done in accordance with IBC Section 1607.14 and
ASCE 7-10 Section 13.5.8, provided substantiating calculations are submitted addressing the fastener-tobase material capacity and the fastener-to-attached material capacity. Interior walls and partitions are
limited to locations where bearing walls, shear walls or braced walls are not required by the approved
plans. The design load on the fastener must not exceed the allowable load shown in Tables 2, 3, 4 and 5, as
applicable.
In particular, IBC 2012 Section 1607.14 states “Interior walls and partitions that exceed 6 feet (1829 mm)
in height, including their finish materials, shall have adequate strength to resist the loads to which they are
subjected but not less than a horizontal load of 5 psf (0.240 kN/m2)”. This contradicts the language
proposed by ICC-ES.
Imposing a 5 psf transverse load limitation on this very common application would essentially render it
undoable with power-driven fasteners, which have been used safely and successfully for cold-formed steel
track attachments for many decades in seismic and non-seismic regions. The ICC-ES proposed load
limitation of 5 psf is not reasonable and will damage both the cold-formed steel industry and the fastener
industry. If the AC hearing discussion additional and arbitrary load limitations are imposed, then Hilti
Hilti, Inc.
nd
5400 South 122 East Avenue
Tulsa, OK 74146
1-800-879-8000
www.hilti.com
would prefer to not include this language in ICC-ES AC70 or the ESRs at all, as it has not been done
historically in this context. Doing so would significantly impact our business in a negative way.
Furthermore, it should also be noted that power-driven fasteners are specifically approved for use in
partition wall track fastening applications by OSHPD in California. If power-driven fasteners are acceptable
for OSHPD, then they should be acceptable to ICC-ES.
Regards,
William G. Gould, P.E.
Director, Codes & Approvals
Hilti, Inc.
Hilti, Inc.
nd
5400 South 122 East Avenue
Tulsa, OK 74146
1-800-879-8000
www.hilti.com
AC70-1012-R1
#12
AC70-1012-R1
#12
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Design Example 1 - Full Height Partition Wall
CFS Interior Nonstructural Walls - Using Power Driven Fasteners
Outline
This example will illustrate the following parts of the design process
A. Transverse (out-of-plane) loads on interior nonstructural walls
B. Design of CFS stud size and spacing
C. Distribution of transverse (out-of-plane) loads to the CFS anchorage
D. Allowable service load for fasteners driven into steel and concrete
Given Information
Interior Nonstructural Wall (Full Height Partition Wall):
Partition Wall Height = 14'-0"
1/2" Gypsum Wallboard each side
Dead Load of Interior Nonstructural Wall (Table C3-1, ASCE 7-10) = 8 psf
Ceiling :
Separation joint between Partition Wall and Ceiling meeting Ceiling horizontal deflections
requirements of ASCE 7-10
z/h = 1.0 (Value 1.0 allows for installation at any floor or roof level of the building)
CFS stud and runner (track)material strength:
Fy = 33 ksi ; Fu = 45 ksi
Power Driven Fasteners fastening to:
Case 1, Structural Steel Support, 3/16" thick steel, ASTM A36
Case 2, 4" thick, normal-weight Concrete, f'c = 2500 psi
Code Level Seismic Design Lateral Load Criteria:
Ip (Component Importance factor per Section 13.1.3, ASCE 7-10)
= 1.5
SDS (Spectral acceleration, short period)
= 1.95
A - Transverse (out-of-plane) Loads on Interior Nonstructural Walls
1. Interior walls and partitions that exceed 6'-0" in height,--- shall have adequate strength
to resist the loads to which they are subjected to but not less than a horizontal load of 5 psf,
per Section 1607.14 of 2012 IBC.
2. For all Seimic Design Categories (A, B, C, D, E and F) Seismic Design Force shall be calculated
per Section 13.3.1 of ASCE 7-10.
3. Partitions that are tied to the ceiling and all partitions greater than 6 ft in height shall be laterally
braced---. Bracing shall be spaced to limit horizontal deflection---. EXCEPTION: 1.-----. 2. ------, 3. The
partitition horizontal seismic load does not exceed 5 psf, per Section 13.5.8.1 of ASCE 7-10.
4. Maximum transverse (out-of-plane) load is limited to 10 psf for Non-Structural member, per Section A2,
Definitions of AISI S200.
Generally ASD seismic transverse loads (0.7E) calculated per A 2 above are less than 5psf, thus
minimum transverse load of 5 psf specified per A 1 above governs.
Note that 10psf limit specified in A4 above is not a minimum transverse load for the design of
non-structural member.
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B - Design of CFS stud size and spacing
9/4/2012
1. Seismic Design Force:
0.4 ap SDS Wp (1 + 2 (z/h))
Fp =
(13.3-1)
(Rp/Ip)
Fp ≤ 1.6SDSIpWp
(13.3-2)
= 1.6x1.95x1.5Wp=
4.68Wp
Fp ≥ 0.3SDSIpWp
(13.3-3)
= 0.3x1.95x1.5Wp=
ap = 1.00
0.88Wp
Rp = 2.50
Table 13.5-1, ASCE 7-10
At any level of floor or roof level of the building
(Fp) = 0.4x1.0x1.95x(1+2(1.0)
(2.5/1.5)
= 1.40Wp
Use Fp = 1.40 Wp
≥ 0.88 Wp
≤ 4.68 Wp
Transverse load on wall
(Fp)ASD = 1.40 x 8 psf/1.4
= 8.0 psf
Use 8 psf
Seismic Load (ASD) Governs
≥ 5 psf (see A1, page 1)
≤ 10 psf (see A4, page 1)
For Serviceability, Gypsum Wallboard finish is classified as flexible finish, per Section 1604.3
(Table 1604.3) of 2012 IBC, deflection limit = L/120.
Using Interior Non-Structural Non-Composite, Wall Height Tables, Steel Stud Manufacturers Association,
ICBO ER-4943P*, Product Technical Information, following is stud size and spacing:
* Note that this Product Technical Information does not comply with 2012 IBC.
362S 125-27 @ 16" o.c.:
Limiting Wall Height = 15'-11" (for 7.5 psf)
Limiting Wall Height = 13'-10" (for 10 psf)
For Partition Wall Height = 14'-0" and 8 psf;
USE 362S 125-27 (Fy = 33 ksi; Fu = 45 ksi) @ 16" o.c.
C - Tranverse (out-of-plane) Loads to the CFS Anchorage
Calculation of shear load to CFS anchorage
Shear load (ASD) to CFS anchorage at top or bottom of wall = (1.40/1.4) x 8 lbs/ft x 14.0'/2 = 56 lbs / ft
3 of 4
D - Allowable Service Load for Fasteners Driven into Steel and Concrete
1. Allowable Service Loads for fastener driven into steel:
3/16" thick steel (support thickness), ASTM A36
Using Hilti Universal Knurled Shank fastener X-U, Shank Diameter d = 0.157"
Allowable Shear Load = 720 lbs (Table 2, ICC-ES, ESR-2269)
2. Allowable Service Loads for fastener driven into concrete:
4" thick (support thickness) normal-weight concrete, f'c = 2500 psi
Using Hilti Universal Knurled Shank fastener X-U, Shank Diameter d = 0.157"
For minimum embedment = 1" < 4"/3 = 1.33" (Max. Embed)
Allowable Shear Load = 190 lbs (Table 3, ICC-ES, ESR-2269)
3. Allowable Service Loads for fastener "Limited by Tilting and Bearing", Section E4.3.1, AISI S100:
CFS runner (track) 27 mils (design thickness = 0.0283")
Fy = 33 ksi ; Fu = 45 ksi
Using Hilti Universal Knurled Shank fastener X-U, Shank Diameter d = 0.157"
Allowable Shear Load
= (2.7 x t1 x d x Fu1)/Ω
; Ω = 3.0
(Eq. E4.3.1-4)
(t2/t1 ≥2.5)
= (2.7 x 0.0283 x 0.157" x 45000psi)/3.0
Allowable Shear Load
Case 1,
= 180 lbs
Structural Steel Support, 3/16" thick steel, ASTM A36
Allowable Shear Load = 180 lbs, item 3 above governs
Anchorage at top and bottom of wall:
Fastener spacing = (180 lb/ft / 56 lb/ft)x12 = 38.6"
Use Hilti Universal Shank Fastener X-U
at 36" o.c. (ICC-ES ESR-2269)
Case 2,
4" thick, normal-weight Concrete, f'c = 2500 psi
Allowable Shear Load = 180 lbs, item 3 above governs
Anchorage at top and bottom of wall:
Fastener spacing = (180 lb/ft / 56 lb/ft)x12 = 38.6"
Use Hilti Universal Shank Fastener X-U (Min. Embed = 1")
at 24" o.c.* (ICC-ES ESR-2269)
* Spacing of power driven fasteners (Fastening of runner to concrete slabs)
not to exceed 24" o.c. per Section 5.2.2 of ASTM C754.
9/4/2012
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Codes and Reference Standards:
1. 2012 International Building Code (IBC), International Code Council.
2. ASCE/SEI 7-10, Minimum Design Loads for Buildings and Other Structures, American Society of
Civil Engineers.
3. AISI S100, North American Specification for Design of Cold-Formed Steel Structural Members, 2007.
4. AISI S200, North American Standard for Cold-Formed Steel Framing - General Provisions, 2007.
5. Standard Specification for Installation of Steel Framing Members to Receive Screw-Attached Gypsum Panel
Products (ASTM C754).
9/4/2012
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Design Example 2 - Partial Height Partition Wall
CFS Interior Nonstructural Walls - Using Power Driven Fasteners
Outline
This example will illustrate the following parts of the design process
A. Transverse (out-of-plane) loads on interior nonstructural walls
B. Design of CFS stud size and spacing
C. Distribution of transverse (out-of-plane) loads to the CFS anchorage
at bottom of wall only
D. Allowable service load for fasteners driven into steel and concrete
Given Information
Five story Building, each story height = 15'-0"
Average roof height of structure (h)= 75'-0"
Interior Nonstructural Wall (Partial Height Partition Wall):
Partition Wall above 4th floor, Height = 12'-0"
1/2" Gypsum Wallboard each side
Dead Load of Interior Nonstructural Wall (Table C3-1, ASCE 7-10) = 8 psf
Ceiling:
Partition that are tied to the ceiling shall be laterally braced to the building structure
per Section 13.5.8.1 of ASCE 7-10. This example assumes ceiling lateral load
is transferred by the brace above to the building structure
CFS stud and runner (track)material strength:
Fy = 33 ksi ; Fu = 45 ksi
Power Driven Fasteners fastening to:
Case 1, Structural Steel Support, 3/16" thick steel, ASTM A36
Case 2, 4" thick, normal-weight Concrete, f'c = 2500 psi
Code Level Seismic Design Lateral Load Criteria:
Ip (Component Importance factor per Section 13.1.3, ASCE 7-10)
= 1.0
SDS (Spectral acceleration, short period)
= 1.25
A - Transverse (out-of-plane) Loads on Interior Nonstructural Walls
1. Interior walls and partitions that exceed 6'-0" in height,--- shall have adequate strength
to resist the loads to which they are subjected to but not less than a horizontal load of 5 psf,
per Section 1607.14 of 2012 IBC.
2. For all Seimic Design Categories (A, B, C, D, E and F) Seismic Design Force shall be calculated
per Section 13.3.1 of ASCE 7-10.
3. Partitions that are tied to the ceiling and all partitions greater than 6 ft in height shall be laterally
braced---. Bracing shall be spaced to limit horizontal deflection---. EXCEPTION: 1.-----. 2. ------, 3. The
partitition horizontal seismic load does not exceed 5 psf, per Section 13.5.8.1 of ASCE 7-10.
4. Maximum transverse (out-of-plane) load is limited to 10 psf for Non-Structural member, per Section A2,
Definitions of AISI S200.
Generally ASD seismic transverse loads (0.7E) calculated per A2 above are less than 5psf, thus
minimum transverse load of 5 psf specified per A1 above governs.
Note that 10 psf limit specified in A4 above is not a minimum transverse load for the design of
non-structural member.
9/4/2012
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B - Design of CFS stud size and spacing
9/4/2012
1. Seismic Design Force:
Fp =
0.4 ap SDS Wp (1 + 2 (z/h))
(13.3-1)
(Rp/Ip)
Fp ≤ 1.6SDSIpWp
(13.3-2)
= 1.6x1.25x1.0Wp=
Fp ≥ 0.3SDSIpWp
2.00Wp
= 0.3x1.25x1.0Wp=
0.38Wp
ap = 1.00
(13.3-3)
Rp = 2.50
Table 13.5-1, ASCE 7-10
At fourth floor base, z = 60.0'
(Fp) = 0.4x1.0x1.25x(1+2(60.0/75.0)
(2.5/1.0)
= 0.52Wp
Use Fp = 0.52 Wp
At top of partition wall, z = 72.0'
(Fp) = 0.4x1.0x1.25x(1+2(72.0/75.0)
(2.5/1.0)
= 0.58Wp
Use Fp = 0.58 Wp
Transverse load on wall
(Fp)ASD = 0.5(0.52 + 0.58)8 psf/1.4
= 3.1 psf
Use 5.0 psf
≥ 5 psf (see A1, page 1)
For Serviceability, Gypsum Wallboard finish is classified as flexible finish, per Section 1604.3
(Table 1604.3) of 2012 IBC, deflection limit = L/120.
Using Interior Non-Structural Non-Composite, Wall Height Tables, Steel Stud Manufacturers Association,
ICBO ER-4943P*, Product Technical Information, following is stud size and spacing:
* Note that this Product Technical Information does not comply with 2012 IBC.
250S 125-18 @ 16" o.c.:
Limiting Wall Height = 12'-0" (for 5.0 psf)
USE 250S 125-18 (Fy = 33 ksi; Fu = 45 ksi) @ 16" o.c.
C - Tranverse (out-of-plane) Loads to the CFS Anchorage
Calculation of shear load to CFS anchorage
Shear load (ASD) to CFS anchorage at bottom of wall = (0.52/1.4) x 8 lbs/ft x 12.0'/2 = 18 lbs / ft
Shear load (ASD) to CFS anchorage at bottom of wall = 5 psf x 12.0'/2
= 30 lbs / ft
Governs
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D - Allowable Service Load for Fasteners Driven into Steel and Concrete
1. Allowable Service Loads for fastener driven into steel:
3/16" thick steel (support thickness), ASTM A36
Using Hilti Universal Knurled Shank fastener X-U, Shank Diameter d = 0.157"
Allowable Shear Load = 720 lbs (Table 2, ICC-ES, ESR-2269)
2. Allowable Service Loads for fastener driven into concrete:
4" thick (support thickness) normal-weight concrete, f'c = 2500 psi
Using Hilti Universal Knurled Shank fastener X-U, Shank Diameter d = 0.157"
For minimum embedment = 1" < 4"/3 = 1.33" (Max. Embed)
Allowable Shear Load = 190 lbs (Table 3, ICC-ES, ESR-2269)
3. Allowable Service Loads for fastener "Limited by Tilting and Bearing", Section E4.3.1, AISI S100:
CFS runner (track) 18 mils (design thickness = 0.0188")
Fy = 33 ksi ; Fu = 45 ksi
Using Hilti Universal Knurled Shank fastener X-U, Shank Diameter d = 0.157"
Allowable Shear Load
= (2.7 x t1 x d x Fu1)/Ω
; Ω = 3.0
(Eq. E4.3.1-4)
(t2/t1 ≥2.5)
psi
= (2.7 x 0.0188 x 0.157" x 45000 )/3.0
Allowable Shear Load
Case 1,
= 120 lbs
Structural Steel Support, 3/16" thick steel, ASTM A36
Allowable Shear Load = 120 lbs, item 3 above governs
Anchorage at bottom of wall:
Fastener spacing = (120 lb/ft / 30 lb/ft)x12 = 48.0"
Use Hilti Universal Shank Fastener X-U
at 48" o.c. (ICC-ES ESR-2269)
Case 2,
4" thick, normal-weight Concrete, f'c = 2500 psi
Allowable Shear Load = 120 lbs, item 3 above governs
Anchorage at bottom of wall:
Fastener spacing = (120 lb/ft / 30 lb/ft)x12 = 48.0"
Use Hilti Universal Shank Fastener X-U (Min. Embed = 1")
at 24" o.c.* (ICC-ES ESR-2269)
* Spacing of power driven fasteners (Fastening of runner to concrete slabs)
not to exceed 24" o.c. per Section 5.2.2 of ASTM C754.
9/4/2012
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Codes and Reference Standards:
1. 2012 International Building Code (IBC), International Code Council.
2. ASCE/SEI 7-10, Minimum Design Loads for Buildings and Other Structures, American Society of
Civil Engineers.
3. AISI S100, North American Specification for Design of Cold-Formed Steel Structural Members, 2007.
4. AISI S200, North American Standard for Cold-Formed Steel Framing - General Provisions, 2007.
5. Standard Specification for Installation of Steel Framing Members to Receive Screw-Attached Gypsum Panel
Products (ASTM C754).
9/4/2012
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Design Example 3
Based on OSHPD Preapproved Details (OPD) - 2010 CBC Standard Partition Wall Details
CFS Interior Nonstructural Walls - Using Power Driven Fasteners
Outline
This example will illustrate the following:
A. Transverse (out-of-plane) loads on interior nonstructural walls
Given Information*
* From Reference 1
Partition Wall Height = 9'-0" to 16'-0"
Interior Nonstructural Wall (Full Height Partition Wall):
Two layers of Gyp Board on one side
or one layer of Gyp Board on both sides
Dead Load of Interior Nonstructural Wall = 7.5 psf
(See General Notes 7C, sheet ST0.01)
Seismic Coefficients (See General Notes 7D, sheet ST0.02):
ap
= 1.0
Rp
= 2.5
Ip (Component Importance factor)
= 1.5
SDS (Spectral acceleration 0.25 to 1.95, use 1.95)
= 1.95
z/h = 1.0 (Value 1.0 allows for installation at any floor or roof level of the building)
A - Transverse (out-of-plane) Loads on Interior Nonstructural Walls
1. Interior walls and partitions that exceed 6'-0" in height,--- shall have adequate strength
to resist the loads to which they are subjected to but not less than a horizontal load of 5 psf,
per Section 1607A.13 of 2010 CBC.
2. For all Seimic Design Categories (A, B, C, D, E and F) Seismic Design Force shall be calculated
per Section 13.3.1 of ASCE 7-05.
3. Maximum transverse (out-of-plane) load is limited to 10 psf for Non-Structural member, per Section A2,
Definitions of AISI S200.
Seismic Design Force:
Fp =
0.4 ap SDS Wp (1 + 2 (z/h))
(13.3-1)
(Rp/Ip)
Fp ≤ 1.6SDSIpWp
= 1.6x1.95x1.5Wp=
(13.3-2)
4.68Wp
Fp ≥ 0.3SDSIpWp
= 0.3x1.95x1.5Wp=
(13.3-3)
0.88Wp
(Fp) = 0.4x1.0x1.95x(1+2(1.0)
(2.5/1.5)
= 1.40Wp
Use Fp = 1.40 Wp
≥ 0.88 Wp
≤ 4.68 Wp
Transverse load on wall
(Fp)ASD = 1.40 x 7.5 psf/1.4
= 7.5 psf
Seismic Load (ASD) Governs
≥ 5 psf (see A1, page 1)
≤ 10 psf (see A4, page 1)
9/4/2012
2 of 2
9/4/2012
Codes and Reference Standards:
1. 2010 California Building Code (Based on 2009 International Building Code).
2. ASCE/SEI 7-05, Minimum Design Loads for Buildings and Other Structures, American Society of
Civil Engineers.
References:
1. OSHPD Preapproved Details (OPD) - 2010 CBC Standard Partition Wall Details.
AC70-1012-R1
#12
AC70-1012-R1
#12
September 11, 2012
Mr. Brian Gerber, S.E.
Principal Structural Engineer
ICC Evaluation Services, LLC.
5360 Workman Mill Road
Whittier, CA 90601
RE: Proposed Revisions to the Acceptance Criteria for Fasteners Power-driven into
Concrete, Steel, and Masonry Elements, Subject AC70-1012-R1
Dear Mr. Gerber,
We have reviewed the changes to AC70 that have been suggested and provide the following
comments.
Item #3
Please clarify whether the 1/8 inch minimum thickness limitation proposed is also applicable to
Section 3.4.3.1 where the minimum thickness is listed as 3/16 inch.
Item #4
While we understand the changes proposed to reflect Section 13.4.5 of ASCE 7, we recommend
language be added to clarify that the use of fastener in steel material to resist seismic load of up
to 250 pounds is for connection of a nonstructural component. The language may be suggested as
follows:
In steel base materials when used for non-structural applications where the service load
on any individual fasteners does not exceed the lesser of 250 pounds (1112 N) or the
published allowable load.
Item #5
Please clarify whether the minimum thickness limitation for steel listed in Section 1.2 is
applicable to metals other than steel. While we do not object to adding metals other than steel to
AC70, it may be appropriate to discuss the issue of galvanic corrosion of dis-similar metals.
Thank you for consideration of these comments. Should you have any questions, please do not
hesitate to contact me.
Sincerely,
Ken Cho, P.E.
Engineer
kcho@strongtie.com
Simpson Strong-Tie Company Inc.
5956 W. Las Positas Boulevard
Pleasanton, CA 94588
Phone: 925.560.9000
Fax: 925.847.3871
www.strongtie.com
AC70-1012-R1
#12
AC70-1012-R1
#12