STATE OF CALIFORNIA
BUILDING STANDARDS COMMISSION
INITIAL STATEMENT OF REASONS
FOR
PROPOSED BUILDING STANDARDS
OF THE
DIVISION OF THE STATE ARCHITECT - STRUCTURAL SAFETY (DSA-SS AND DSA-SS/CC)
REGARDING THE CALIFORNIA BUILDING CODE
CALIFORNIA CODE OF REGULATIONS, TITLE 24, PART 2
The Administrative Procedure Act (APA) requires that an Initial Statement of Reasons be available to the public upon request when rulemaking action is being undertaken. The following information required by the APA pertains to this particular rulemaking action:
STATEMENT OF SPECIFICPURPOSE,PROBLEM, RATIONALE and BENEFITS:
(Government Code Section 11346.2(b)(1)) requires a statement of specific purpose of each adoption, amendment, or repealand the problem the agency intends to address and the rationalefor the determination by the agency that each adoption, amendment, or repeal is reasonably necessary to carry out the purpose and address the problem the agency intends to addressfor which it is proposed. The statement shall enumerate the benefits anticipated from the regulatory action, including the benefits or goals provided in the authorizing statute.)
The purpose of this proposed action is to adopt the 2019 California Building Code (2019 CBC) based on new information since the adoption of the 2016 CBC.
TITLE 24, PART 2, VOLUME 1
CHAPTER 1 – SCOPE AND ADMINISTRATION
Section 1.9.2.1.1 - DSA amendment adopted as emergency regulations have been adopted in 2016 IBC. Amended emergency sections are being repealed and adopted language relocated from 107.2.7 to 107.2.5 and 110.3.8.1 to 110.3.6.
Sub-section 1.1, reference Sections 4-401 through 4-435 were previously adopted in 2013 CAC, but not added into Section 1.9.2.1.1 at that time. This amendment updates the applicable administrative standards to include the adopted regulations.
Section 1.9.2.2.1 - DSA amendment adopted as emergency regulations have been adopted in 2016 IBC. Amended emergency sections are being repealed and adopted language relocated from 107.2.7 to 107.2.5 and 110.3.8.1 to 110.3.6.
Sub-section 1.1, reference Sections 4-401 through 4-435 were previously adopted in 2013 CAC, but not added into Section 1.9.2.2.1 at that time. This amendment updates the applicable administrative standards to include the adopted regulations.
Section 107.2.7 - Amendment section 107.2.7 language repealed because it is now included in model code section 107.2.5
Section 110.3.8.1 - Amendment section 110.3.8.1 language repealed because it is now included in model code section 110.3.6.
TITLE 24, PART 2, VOLUME 1
CHAPTER 2 – DEFINITION
Definition: NEXT GENERATION ATTENUATION 2 (NGA 2). Updated definition to reference new NGA 2 relations; used to determine site-specific ground motion (as referenced by 1803A.6
Definition: ACTIVE EARTHQUAKE FAULT.Relocating this amendment from 2016 CBC 1613A.2 to here because model code (2018 IBC) removed “terms” listings from front of chapters. All definitions are located here in Chapter 2.
Definition: BASE. Relocated from 2016 CBC 1613A.2
Definition: DISTANCE FROM AN ACTIVE EARTHQUAKE FAULT.Relocated from 2016 CBC 1613A.2
New Definition: EQUIPMENT. Added to align with OSHPD definition of equipment; includes definition of fixed, moveable and mobile equipment, and examples of common usage. Several provisions within Chapter 16A and 17A include reference to equipment; these definitions have been added to help provide clarity.
Definition: HIGH-RISE BUILDING.Relocated from 2016 CBC 1613A.2
Definition: IRREGULAR STRUCTURE.Relocated from 2016 CBC 1613A.2
Definition: PROJECT INSPECTOR, Quality Assurance (QA), and Quality Control (QC).Relocated from 2016 CBC 1702A.1.
Definition: [BS] SPECIAL INSPECTION. - Periodic special inspection.Relocated definition (from 1702A)and amending to better align with model code language.
Definition: [BS] WALL (for Chapter 21).Relocated from CBC 2102A.1.
TITLE 24, PART 2, VOLUME 2
CHAPTER 14 – EXTERIOR WALLS
Section 1404 - 2018 IBC eliminated Section 1402, thus requiring sections numbers to be renumbered throughout Chapter 14.
TITLE 24, PART 2, VOLUME 2
CHAPTER 15 – ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
Section 1502 - Section 1502 revised to Roof drainage in 2018 IBC. Also revised reference from Chapter 11 to specific sections 1106 and 1108. Need to verify accuracy of sections 1106 and 1108 vs Chapter 11 in IPC once available
Section 1510.7.1 – Section removed in 2018 IBC; thus also eliminating existing DSA exception. The provisions of this section are being retained in the revisions to 1510.7.2.
Section 1510.7.2 - This proposal provides pointers to new sections that were added to ASCE 7-16 (13.6.12, 29.4.3 and 29.4.4) which provide direction regarding seismic and wind design requirements for Rooftop solar panels. This proposal also reinstates the wind force requirements and DSA amendment (exception) clarifying the effective wind area on solar panels and modules that were eliminated in Section 1510.7.1 of the 2018 IBC. This proposal allows DSA to enforce code and industry standards where appropriate for the type of anchorage specified on construction documents.
TITLE 24, PART 2, VOLUME 2
CHAPTER 16A – STRUCTURAL DESIGN
Section 1603A.1.5 - Updated reference to definition of base. No regulatory change.
Section 1603A.1.10 - Renumbered from 1603A.1.9 to 1603A.1.10 due to 2015 IBC added section 1603.1.9. No regulatory change to amendment, renumbering only.
Section 1604A.3 - Language in section 1604.3 was updated in 2018 IBC. No regulatory change to model code language, simply adding an “A” in order to reference table 1064A.3.
Table 1604.A.3 - 2018 IBC added “or Lr” to column heading. Continued DSA amendment to add Lr to column heading.
Footnote b - No regulatory change; add “A” to section reference.
Footnote f - No regulatory change; add “A” to table and section references.
Footnote g - Correcting IBC typo.
Section 1604A.3.8 - Renumbered from 1604A.3.7 to 1604A.3.8 due to 2018 IBC added section 1604.3.7. No regulatory change to amendment, renumbering only.
Section 1604A.3.9 - Renumbered from 1604A.3.8 to 1604A.3.9 due to 2018 IBC added section 1604.3.7. No regulatory change to amendment, renumbering only.
Section 1604A.5 - No regulatory change. Add “A” to table reference. No regulatory change.
Section 1604A.5.1 - No regulatory change. Add “A” to table reference.
Section 1605A.1.1 – Amendmentis revised for consistency with newly-added ASCE 7 Section 12.13.5, “Strength Design for Foundation Geotechnical Capacity”. This allowance to use phi (Ø) = 1.0 is intended explicitly and solely for the phi of foundation geotechnical capacity at soil-foundation interface as defined in ASCE 7 Section 12.13.5 (see section 12.13.5.2 and table 12.13-1) when applying load combinations with overstrength factor (o). Section 1617A.1.16 is the DSA and OSHPD amendment to ASCE 7 12.13.1.1 “Foundations and Superstructure-to-Foundation Connections”. The amendment contains 3 options; the most-commonly selected option is to use the overstrength factoro, which amplifies the overturning loads applied to foundations by at least a factor of 2.
The minimum resistance factor Ø for lateral resistance is 0.5. The minimum resistance factor Ø for vertical resistance is 0.45. When amplified loads are applied to the structure, the maximum soil bearing stress is further amplified when soil is designed not to take tension loads. By using Ø = 1.0 when applying load combinations with o, the net effect in the sizing of the foundationswill generally be equal to or greater than other load combinations as required by ASCE 7. The reason for permittingØ = 1.0 for those combinationsis to not penalize the soil bearing pressure; the model code does not apply o to any load combinations intended for checking soil bearing pressure. This allowance to use Ø = 1.0 shall not be extended to design of other elements, only the soil bearing pressure when using strength design per the new ASCE 7-16 Section 12.13.5.
Section 1605A.3 - Add “A” to section reference Section 1605A.3.1 or 1605A.3.2. No regulatory change.
Table 1607A.1 –2018 IBC added new footnotes “n” and “o”; as a result, DSA-SS footnotes “n” through “r” must be renamed to “q” through “t”. Table references have been updated throughout in response to new IBC footnotes and resultant DSA-SS footnote renumbering. No regulatory change to DSA-SS footnotes.
Section 1607A13.6 - Section 1607.8.3 in 2015 IBC was renumbered to 1607.9 in 2018 IBC. Thus, Section 1607A12.6 needs to be renumbered to 1607A.13.6. No regulatory change to continued amendment language.
Section 1607A.15 - Section 1607.8.3 in 2015 IBC was renumbered to 1607.9 in 2018 IBC. Thus, Section 1607A.14 needs to be renumbered to 1607A.15. No regulatory change to continued amendment language.
Section 1609A.1.3- Clarify the exemption for story drift limit is applicable to single story open “structures” in Risk Category I and II, in order to align with original intent of this exception.
Section 1613A.2 - Model code (2018 IBC) removed “defined terms” listings from front of chapters. Definitions formerly noted in Section 1613A.2 have been relocated to Chapter 2.
Section 1613A.2.3 - Add “A” to section reference1613A.2.5. Also, Simplified Design Procedure not permitted by DSA-SS so strike last line. No regulatory change.
Section 1613A.3 - Model code language does not align with new provisions in ASCE 7-16, 13.6.12 Rooftop Solar Panels. Strike language and add reference to comply with ASCE 7 Section 13.6.12
Section 1615A.1 - This proposal adds definition that the project design professional proposes the Tsunami Risk Category (TRC) of a school, community college and essential services building or structure in accordance with ASCE 7 and Commentary; and that DSA accepts the TRC classification based on the ability of the community to evacuate its citizens, including school attendees and employees.
Section 1615A.2 - Model code (2018 IBC) removed “defined terms” listings from front of chapters. Definitions formerly noted in Section 1615A.2 have been relocated to Chapter 2.
Section 1617A - Renumbered from 1616A to 1617A due to numbering changes in model code – typical throughout this section.
Section 1617A.1.2 - Added for clarification
Section 1617A.1.3 - Previous amendment language repealed because ASCE 7-16 now contains similar provisions.
Section 1617A.1.4 – Item G, Exception 3 - Amendment language updated to reflect change in referenced section; no change in regulatory effect.
Section 1617A.1.10 – Proposed exception lifts prohibition on extreme torsional irregularity for Seismic Design Categories D through F where the maximumstory drift in the direction of the irregularity is less than 10% of the allowable story drift. When applying the irregularity check on a structure that is very stiff on 3 sides (for example, full-length shear walls on 3 sides with an open front), calculated deflections will be very small, resulting in a very small denominator in the equation used to check torsional irregularity, thereby causing allowed limits to be exceeded despite very small calculated building drift. Damage or collapse of such rigid structures is unlikely to occur at such low levels of building drift. This exception is necessary for buried structures where one side is required to be open for entry such as a loading dock. The ASCE 7-22 committee is looking into making modifications to this provision to permit structures with extreme torsional irregularities provided drifts are less than 75% of model code, but requiring consideration of load combinations that include orthogonal effects of 100% and 30% in each orthogonal direction applied simultaneously. The proposed provision is conservative and a step in that direction.
Section 1617A.1.12 - Repealing previous amendment, which was added to provide alignment with ASCE 7-16, which is now the adopted reference standard. (ASCE 7-16 Section 12.8.1.3). No change in regulatory effect.
Section 1617A.1.13 - Previous amendment language repealed because ASCE 7-16 Section 12.9.1.4 now contains provisions for scaling design values of combined response.
Section 1617A.1.14 - Previous amendment language repealed because ASCE 7-16 Section 12.10.2.1 now contains equivalent provisions.
Section 1617A.1.16 - Change in section number: Horizontal Seismic Load Effect with Overstrength was Section 12.4.3.2 in ASCE7-10; now Section 12.4.3.1 in ASCE 7-16
Section 1617A.1.18 –Item 2: Changes to distinguish between mobile and moveable equipment, allow exemption from anchorage for mobile equipment that is stored in a storage room.
Item 3: Editorial changes to help clarify requirements.
Section 1617A.1.19 - Revised exception wording for clarity since “not prohibited” is a double negative. Revise to “permitted” for clarity. No regulatory change.
Section 1617A.1.21 - Repealing previous amendment, which was added to the 2016 CBC to provide alignment with ASCE 7-16, which is now the adopted reference standard.
The other proposed modifications in this section are for clarification or editorial in nature.
Section 1617A.1.23 –Repealing previous amendments which were added to align the 2016 CBC with the ASCE 7-16, which is now the current reference standard.
For the new proposed language, there are nonstructural components referenced in the referenced ASCE 7-16 Tables to be designed with an Rp = 1.5 and o of 2. When non-structural components are required to have an Ip of 1.5, force demands on those components having a low Rp values are considered essentially elastic. Therefore, there is no need to account for over strength beyond the elastic limit. In addition, only prequalified anchors in concrete are permitted. These anchors have resistance factors corresponding to a 5% fractile limit which provides the required conservatism needed.
Section 1617A.1.24 –Repealing previous amendments thereby allowing the proposed language to parallel the new ASCE 7-16 language; the intent of previous amendments is generally maintained through new proposed language.While the new proposed language permits exemptions from bracing requirements consistent with ASCE 7 for distribution systems for Conduit, Cable Tray, and Raceways where Ip = 1.0, additional limitations have been added to limit the maximum rod length and load that can be hung per rod.
Section 1617A.1.25 - Repealing previous amendments thereby allowing the proposed language to parallel the new ASCE 7-16 language; the intent of previous amendments is generally maintained through new proposed language. While the new proposed language permits exemptions from bracing requirements consistent with ASCE 7 for distribution systems for Duct Systems where Ip = 1.0, additional limitations have been added to limit the maximum rod length and load that can be hung per rod.
Section 1617A.1.26- Repealing previous amendments thereby allowing the proposed language to parallel the new ASCE 7-16 language; the intent of previous amendments is generally maintained through new proposed language. While the new proposed language permit exemptions from bracing requirements consistent with ASCE 7-16 for distribution systems for piping and tubing systems with Ip =1.0, additional limitations have been added to limit the maximum rod length and load that can be hung per rod.
Section 1617A.1.27 - Updating reference pointer.
Section 1617A.1.28 - Updating reference pointer.
Section 1617A.1.29 through 1617A.1.32 - Repeal amendments from2016 CBC Sedtion1616A.1.29 through 1616A.1.32. Chapter 16 (Seismic Response History Procedures) from ASCE 7-10 deleted; ASCE 7-16 contains a re-written Chapter 16, focused on Nonlinear Response History analysis and corresponding acceptance criteria. Linear Response History procedure has been moved to Section 12.9 and merged with Modal Response Spectrum Analysis to create the re-named Section 12.9 (Linear Dynamic Analysis) which contains Section 12.9.1 Modal Response Spectrum Analysis and Section 12.9.2 Response History Analysis.
Section 1617A.1.29 - Repeal amendments for CBC 16167A.1.29. ASCE 7-16 revised the Linear Response History procedure and moved it to Section 12.9 .2. Per 12.9.2.5, for force-based quantities, design base shear must not be less than that determined by ELF. However for displacement-based quantities, normalization to ELF is not required; need only multiply the computed response history quantities by the appropriate Cd/R in the direction of interest.
Section 1617A.1.30 - Repeal amendments for CBC 16167A.1.30. Chapter 16 of ASCE 7-16 re-written to focus on Nonlinear Response History analysis and now includes corresponding acceptance criteria.
Section 1617A.1.31 - ASCE 7-10 Section 16.2.3 did not indicate how to combine the live load requirement, so previous amendment for CBC 16167A.1.31 was provided to clarify that it shall be per the standard load combinations. ASCE 7-16 now provides direction in Section 16.3.2; therefore, repeal previous amendment for CBC 16167A.1.31.
Section 1617A.1.32 - Repeal amendment language for CBC 16167A.1.32 because ASCE 7-16 Section 16.2 now contains provisions for ground motion selection and refers to Section 11.4.1 for definition of near-fault sites.
Section 1617A.1.37 - Repealing previous amendment, because similar provisions are now included in ASCE 7-16 Section 17.6.4
Section 1617A.1.38 -Continued amendment language, edited to adjust for re-numbering due to adjustments made to ASCE 7-16. Also, for clarity, remove language regarding DE and retain reference to MCER. No regulatory change.
TITLE 24, PART 2, VOLUME 2
CHAPTER 17A - SPECIAL INSPECTIONS AND TESTS
Section1701A.1.3 - Provides clarifying language since not all DSA-SS reference numbers directly correlate with DSA-SS/CC section numbers.
Section 1702A.1: In the 2016 CBC, 1702A was for definitions; the 2018 IBC replaced this section with “New Materials.” Therefore, previous amendment definitions are being either removed or relocated as shown below.
Relocated definitions to Section 202: PROJECT INSPECTOR, Quality Assurance (QA), Quality Control (QC),
Removing definition: Continuous special inspection - Deleting language for “continuous special inspection” since Section 202 definition is sufficient.
Relocating to Section 202 and amending definition: Periodic special inspection. - (see Chapter 2 Express Terms and Statement of Reasons).
Section 1704A.2.5 - Striking new language since DSA does not have approved fabricators, just as in the 2016 CBC.
Section 1704A.2.5.1 - DSA is continuing deletion of this section and new language associated with it since DSA does not have approved fabricators, just as in the 2016 CBC.
Section 1704A.5, Item #1 – Minor editorial deletion in line with previous deletions.
Section 1704A.6 - Removing new model code reference since that section is being removed by amendment (see Statement of Reasons for sections 1704.6.1, 1704.6.2, and 1704.6.3).
Sections1704.6.1, 1704.6.2, and 1704.6.3 - The CAC requires structural observation requirements to all DSA regulated projects rather than only certain types. Therefore, section 1704.6.1 is amended for removal which is consistent with past similar removal amendments. Sections 1704.6.2 and 1704.6.3 have minor editorial deletions in line with past removal amendments.
Section 1705A.2.1 - No net change in regulation. Changes shown are editorial in nature and merely align requirements with current AISC 360-16 sections and language.
TABLE 1705A.2.1 - Providing reference pointers and recognizing tests and special inspections already required in other sections; no new testing or special inspections being added nor proposed.
Adding items 1c, 3d, 4c, 5a7, 5a8, and 5b5 to explicitly recognize their special inspection requirements. Special inspection has been required previously and is currently for these items. No net regulatory change occurs with proposed additions.
Section 1705A.2.2 - Acknowledgment that testing is part of the referenced table and section. No new testing results from the proposed language since testing is already required in the Sections noted in the remaining portion of the statement.
Section 1705A.2.4.1 - Providing clarifying language for the intent of the existing amendment, that is, special inspection is required for all light-framed steel trusses.
2211.1.3.3 has a new reference to AISI 240 Chapter D for QC requirements of trusses fabricated without QC. The proposed language is merely pointing to that section.
Section 1705A.2.5 - Providing reference to existing code sections; no new testing or special inspection requirements. Adding language recognizing that, in accordance with CAC 4-335(f), only those special inspectors employed individually and directly with the school board require DSA approval.