asce-7-10 changes.pdf

Side-by-Side Comparison of Seismic Provisions of ASCE 7-10 to ASCE 7-05 with PUC Member Comments on Modifications Proposed in 2009 Provisions Part 1

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Comments Section Provision Section Significant Revisions

Attachment 4A to PUC December 2010 Meeting Agenda of 30

Chapter 11, SEISMIC DESIGN CRITERIA Per Harris: Table 12.2-1 of ASCE 7-10 contains the requirements of AAC as published in the 2009 NEHRP Part 1. The corresponding

modifications for Chapter 14.4 (.3) are not included in ASCE 7-10. 11.1.2 Scope This section lists four types

of structure that are exempt from the seismic requirements.

11.1.2 Scope A fifth exemption has been added: “piers and wharves that are not accessible to the general public.”

The 2009 NEHRP modifications to ASCE 7-05 were not incorporated into ASCE 7-10.

11.1.3 Applicability

This section indicates which chapter covers what type of system.

11.1.3 Applicability Text was added indicating that buildings whose purpose is enclosing equipment and machinery may be designed as a non-building structure (Chapter 15)

11.2 Definitions This section has all the definitions for the seismic provisions of this Standard.

11.2 Definitions Minor revisions with potential substantive impacts have been made to the definitions for “attachments”, “component”, “designated seismic systems”, “grade plane”, “story above grade”, “supports”. The following definitions have been deleted: “basement”, “component support”, “hazardous contents”, “importance factor”. The following definitions have been added: “friction clip”, “structural height”.

Some added definitions were reviewed in conjunction with PUC-addressed revisions. Per Kircher (see also 11.3, 11.4, Ch. 21, Ch. 22): The definition of the MCER in Section 11.2, terms defining mapped values of MCER spectral acceleration in Section 11.3, design requirements and equations defining seismic MCER ground motion values in Section 11.4 and related ground motion maps of Chapter 22 are different in ASCE 7-10 and the 2009 Provisions. There are other related editorial differences in ASCE 7-10 and the 2009 Provisions, including differences in table labels (e.g., Table 11.4.1 and 11.4.2) and section headings (e.g., Chapter 21).

Note to the PUC: The design values of ASCE 7-10 and the 2009 Provisions are identical. The ground motion maps (Chapter 22) and process defining design values (Section 11.4) were


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simplified by the SSC of ASCE 7 when the new ground motions of the 2009 Provisions were adopted for use in ASCE 7 (and by reference the 2012 IBC). Recommendation - The PUC should choose to either (1) adopt the simplifying/editorial changes of ASCE 7-10 in their entirety and begin the cycle with material identical to that of ASCE 7-10 (and the 2012 IBC), or (2) reject all simplifying/editorial changes of ASCE 7-10 and begin the next cycle with material identical to that of the 2009 NEHRP Provisions. It would be counterproductive to piecemeal accept/reject each ASCE 7-10 change. The second option would maintain the "clarity" of the 2009 Provisions, but affect a divergence with ASCE 7 that would make changes to the 2014 Provisions problematic when brought forward for consideration by the SSC of ASCE 7.

11.3 Notation This section includes all the notations for seismic provisions of this Standard.

11.3 Symbols Some added and revised symbols. Any substantive changes are covered in the section of text to which the change relates.

Some added notation reviewed in conjunction with PUC-addressed revisions. See Kircher comments on Sec. 11.2 above.

11.4 Seismic Ground Motion Values 11.4.1 thru 11.4.7

Section defines the seismic ground motion parameters

11.4 Seismic Ground Motion Values 11.4.1 thru 11.4.7

Revisions relate to the change to “risk-targeted” ground motions

Revisions are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, and the comparison is addressed by the PUC. See Kircher comments on Sec. 11.2 above.

11.5 Importance Factor and Occupancy

Section assigns importance factor based on occupancy category

11.5 Importance Factor and Risk Category

Substantively the same except terminology changes and Importance Factor table moved to


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Category 11.5.1 11.5.2

11.5.1 11.5.2

Chapter 1.

11.7 Design Requirements for Seismic Design Category A 11.7.1 11.7.2 11.7.3 11.7.4 11.7.5

Section provides limited seismic requirements for buildings assigned to SDC A including lateral forces, load path, connections, and wall anchorage.

11.7 Design Requirements for Seismic Design Category A 11.7.1

Section has been replaced by a reference to Section 1.4 General Structural Integrity and exempts nonstructural components in SDC A from seismic design requirements except for the tank freeboard requirements (Sec. 15.7.6.1.2) in Risk Category IV buildings. The provisions of Section 1.4 have the same general lateral force, load path and connection requirements of ASCE 7-05, except that the loading requirements for anchorage of structural walls (ASCE 7-05 Sec 11.7.5 renumbered to Sec 11.7.1) has been changed and it now applies to all types of walls, not just concrete and masonry.

11.8 Geologic Hazards and Geotechnical Investigation 11.8.1 11.8.2 11.8.3

Section provides site limitations for SDC E/F and geotechnical investigation requirements.

11.8 Geologic Hazards and Geotechnical Investigation 11.8.1 11.8.2 11.8.3

Revisions include many editorial changes and revised requirements for SDC D to F.

Revisions are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, but the matter has been addressed by the PUC. Crouse: The difference between the two documents is editorial for the most part.

In Section 11.8.2, editorial differences occur in sentence above the Exception and within the Exception.

In Section 11.8.3, Paragraph 2, the phrase, “maximum considered earthquake geometric mean,” on p. 9 in


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the NEHRP provisions is replaced with “MCEG” on pp. 67 & 68 of ASCE 7-10. Also, the phrase “Figs. 22-6 through 22-10” in the definition of PGA under Eq. 11.8-1 in ASCE 7-10 should read “Figs 22-7 through 22-11”.

Editorial differences are noted in Section 11.8.3, Paragraphs 3 and 4.

In Table 11.8-1 the header beginning with the word, Mapped, is editorially different in the two documents.

Chapter 12, SEISMIC DESIGN REQUIREMENTS FOR BUILDING STRUCTURES

12.2.1 Selection and Limitations

Provides the basic seismic force-resisting systems and design criteria in Table 12.2-1.

12.2.1 Selection and Limitations

A summary of the revisions is as follows: Bearing Wall Systems Added section references for

detailing requirements associated with concrete shear wall systems.

New AAC systems will be addressed by the PUC.

Light-frame systems of wood and cold-formed steel have been separated but no changes to design values.

Building Frame Systems Revisions to steel eccentrically

braced frames will be addressed by the PUC.

Added section references for detailing requirements associated with concrete shear wall systems.

Some of the system revisions are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, but the comparison has been addressed by the PUC as have the revised detailing references for steel and concrete systems which are addressed here and in conjunction with the PUC-review of the relevant sections of Chapter 14. Per Malley: I have confirmed that the changes to Table 12.2-1 of ASCE 7-10 related to steel EBF and BRBF are identical to those in FEMA 750. Also, in Section 14.1.1 of FEMA 750, the changes to AISC 341-10 were essentially identical, with an editorial style change and clarification in AISC 341-10 added to FEMA 750 language. Per Harris: Table 12.2-1 of ASCE 7-10


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Light-frame systems of wood and cold-formed steel have been separated but no changes to design values.

Revisions to steel buckling-restrained braced frames will be addressed by the PUC.

Moment-Resisting Frame Systems Deleted section referenced for

detailing requirements for steel intermediate and ordinary moment frames.

New cold-formed steel special bolted moment frames will be addressed by the PUC.

Shear Wall-Frame Interactive System with Ordinary Reinforced Concrete Moment Frames and Ordinary Reinforced Concrete Shear Walls - Deleted section reference for

detailing requirements Cantilevered Column Systems Detailed to Conform to the Requirements for: Deleted section reference for

detailing requirements for steel special cantilever column systems.

Deleted intermediate steel moment frame system.

The reduction in overstrength factor per footnote g is no longer now prohibited for cantilever columns systems.

contains the requirements of AAC as published in the 2009 NEHRP Part 1. The corresponding modifications for Chapter 14.4 (.3) are not included in ASCE 7-10.


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12.2.3.1 R, Cd, and Wo Values for Vertical Combinations

Section provides requirements for design coefficients for vertical combinations


Requirements for different upper and lower systems have been clarified, and provisions covering scaling of forces for transfer between the upper and lower systems have been added.


Section includes a procedure for a two-stage analysis for vertical combinations

12.2.3.2 Two-Stage Analysis Procedure

Old text moved to a new section but remains substantially the same except for a new provision requiring that the upper portion be analyzed using the ELF or modal response spectrum procedure and the lower analyzed with the ELF.

12.2.5.4 Increased Building Height Limit for Steel Braced Frames and Special Reinforced Concrete Shear Walls

The height limits in Table 12.2-1 are permitted to be increased to 240 ft for structures assigned to SDC D or E and 160 ft for structures assigned to SDC F for certain systems subject to certain conditions.

12.2.5.4 Increased Structural Height Limit for Steel Eccentrically Braced Frames, Steel Special Concentrically Braced Frames, Steel Buckling-restrained Braced Frames, Steel Special Plate Shear walls, and Special Reinforced Concrete Shear Walls

The types of steel braced frames subject to this provision have been clarified and steel special plate shear wall system has been added.


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12.2.5.6 Single-Story Steel Ordinary and Intermediate Moment Frames…. 12.2.5.7 12.2.5.8 12.2.5.9

Sections include special requirements for steel ordinary and intermediate moment frames assigned to SDC D-F.

12.2.5.6 Steel Ordinary Moment Frames 12.2.5.7 Steel Intermediate Moment Frames

The sections have been significantly reorganized, but the only substantive change involves an exception to the height limits for single-story ordinary and intermediate moment frame structures enclosing equipment or machinery subject to certain dead load restrictions.

12.3.1.1 Flexible Diaphragm Condition

ASCE 7 permits certain diaphragms to be idealized as flexible.

12.3.1.1 Flexible Diaphragm Condition

Two limitations have been added for idealizing structures of light-frame construction as flexible: limitations on topping slabs and drift limitations on each line of vertical elements.

12.3.2.1 Horizontal Irregularity

Refers to Table 12.3-1 which lists the irregularities

12.3.2.1 Horizontal Irregularity

Text added to indicate that Ax is 1.0 when computing story drifts for determination of irregularity Type 1a and 1b (torsional).

12.3.2.2 Vertical Irregularity

Refers to Table 12.3-2 which lists the irregularities

12.3.2.2 Vertical Irregularity

Type 4 irregularity (in-plane discontinuity) has been revised to occur where an in-plane offset results in overturning demands on a beam, column, truss, or slab.

12.3.3.4 Increase in Forces Due to Irregularities for Seismic Design Categories D through F

Section covers increased forces for certain irregularities

12.3.3.4 Increase in Forces Due to Irregularities for Seismic Design Categories D through F

The increased forces are specified as the diaphragm forces of Section 12.10.1.1 rather than the base shear forces of Section 12.8.1

12.3.4.1 Conditions Where Value of � is 1.0

Section includes a list of structures and elements for which the redundancy provision does not apply.

12.3.4.1 Conditions Where Value of � is 1.0

One item has been added to the list: design of structural walls for out-of-plane forces, including their anchorage.


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12.3.4.2 Redundancy Factor, �, for Seismic Design Categories D through F

Section specifies the requirements for the redundancy factor.

12.3.4.2 Redundancy Factor, �, for Seismic Design Categories D through F

Figure 12.3.-2 has been added to clarify the shear wall and wall pier hight-to-length rations associated with the redundancy factor determination, but there is no substantive change.

12.4.3.1 Horizontal Seismic Load Effect with Overstrength Factor

Section covers determination of seismic loads with the overstrength factor.

12.4.3.1 Horizontal Seismic Load Effect with Overstrength Factor

The diaphragm force, Fpx, has been added to the definition of QE though this is more of a clarification than substantive change.

12.6 Analysis Procedure Selection

Refers to Table 12.6-1. 12.6 Analysis Procedure Selection

Several revisions have been made to Table 12.6-1

Revisions are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, but the matter has been addressed by the PUC. Per Pekelnicky: Proposal 2-2R2, which revised the table for permissible analysis procedures, was adopted into ASCE 7-10 with one significant technical change and one editorial change. The editorial change was to break out the row of Structural Characteristics in D, E, F titled “Regular structures not exceeding 160 feet in height and all structures of light frame construction” into two separate rows – one for regular structures not exceeding 160 feet and one for light frame. The significant technical change in the ASCE 7-10 table was the addition of a row in D, E, and F titled “Risk Category I or II buildings not exceeding 2 stories above the base” and permitting those structures to be designed using the Equivalent Lateral Force Procedure. I


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believe the PUC will have to determine if permitting irregular 1 and 2 story above the “base” structures to be designed using the ELF is acceptable.

12.7.2 Effective Seismic Weight

Section defines what is to be included in the structural weight for determining seismic forces.

12.7.2 Effective Seismic Weight

Added provision permitting storage live loads to be neglected it they are small and added provision for including weights of landscape materials

12.7.3 Structural Modeling

Section includes requirements for the analytical modeling

12.7.3 Structural Modeling

Added exception excludes flexible diaphragm structures with Type 4 horizontal irregularities from the 3-D modeling requirement.

12.8.2.1 Approximate Fundamental Period

Section contains provisions for determining the approximate period.

12.8.2.1 Approximate Fundamental Period

Steel buckling-restrained braced frames added as a specific system in Table 12.8-2 with different parameters from what was previously specified for “all other structural systems”.

12.8.4.3 Amplification of Accidental Torsional Moment

Section contains provisions for amplifying accidental torsion for torsionally irregular structures.

12.8.4.3 Amplification of Accidental Torsional Moment

Exception for light-frame construction has been removed from this provision, and text has been added clarifying that Ax shall not be less than 1.0.

12.8.6 Story Drift Determination

Section contains provisions for determining story drift.

12.8.6 Story Drift Determination

Text has been added indicating how to determine drift in conditions where the center of mass does not align vertically, and the text related to torsionally irregular buildings has been moved to this section from Section 12.12.1.

12.8.6.1 Minimum Base Shear for Computing Drift

Section specifies forces for computing drift.

12.8.6.1 Minimum Base Shear for Computing Drift

An exception has been added, removing Eq 12.8-5 from the requirements for computing drift.


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12.8.7 P-Delta Effects

Section provides the requirements for P-delta analysis.

12.8.7 P-Delta Effects

Equation Eq 12.8-6 has been revised to include the importance factor Ie.

Aside from the addition of the importance factor, other 2009 NEHRP revisions to this section were not incorporated into ASCE 7-10.

12.9.3 Combined Response Parameters

Section specifies how to combine modal parameters.

12.9.3 Combined Response Parameters

Revisions allow the use of the CQC method without the ASCE 4 modifications.

12.9.4 Scaling Design Values of Combined Response

Section specifies scaling of modal response parameters.

12.9.4 Scaling Design Values of Combined Response 12.9.4.1 12.9.4.2

Provisions have been split into subsections for forces and drifts, and a substantive change is that scaling applies to drifts where base shear is computed in accordance with Eq 12.8-6 (cases where S1 ≥ 0.6).

12.10.2.1 Collector Elements Requiring Load Combinations with Overstrength Factor for Seismic Design Categories C through F

Section contains requirements for the use of the overstrength factor for collector elements.

12.10.2.1 Collector Elements Requiring Load Combinations with Overstrength Factor for Seismic Design Categories C through F

The provisions have been expanded, clarifying the seismic load effects to be considered for the design of collector elements, including forces associated with base shear and diaphragms (including minimum and maximum values).

12.11.2 Anchorage of Concrete or Masonry Structural Walls 12.11.2.1 12.11.2.2

Section contains requirements for wall anchorage.

12.11.2 Anchorage of Structural Walls and Transfer of Design Forces into Diaphragms 12.11.2.1 12.11.2.2

The wall anchorage requirements have been extended to all structural walls, not just concrete and masonry and the anchorage loads have been revised substantially. Several of the minimum values have been removed, the increased force for flexible diaphragms has been

The 2009 NEHRP modifications to Sections 12.11.2.2.1 and 12.11.2.2.3 were not incorporated into ASCE 7-10.


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revised, and the anchorage force can vary up the height of the building in certain conditions.

12.12.1 Story Drift Limit

Section establishes limits for story drift.

12.12.1 Story Drift Limit

Text related to how to compute story drift for torsionally irregular buildings has been moved to Section 12.8.6. No substantive change.

12.12.3 Building Separation

Section requires structural separations “to avoid damaging contact.”

12.12.3 Structural Separation 12.12.4 Members Spanning between Structures

Equations for determining the required separations have been added, and a new section with requirements for the design of gravity connections for elements spanning across structural separations has been added.

12.14.1.1 Simplified Design Procedure

Section provides the limitations, including permitted seismic force-resisting systems for use of the Simplified Procedure.

12.14.1.1 Simplified Design Procedure

There have been no substantive revisions to the 12 items in this section. In Table 12.14-1, wood and cold-formed steel systems have been separated but there are no changes to the design requirements.

12.14.7.2 Openings or Reentrant Building Corners

Section provides requirements for edge reinforcement around openings and at reentrant corners, except for perforated shear walls that are designed based on the AF&PA SDPWS.

12.14.7.2 Openings or Reentrant Building Corners

A second exception for AISI S213 Type II shear walls with cold-formed framing has been added to the section.


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12.14.7.5 Anchorage of Concrete or Masonry Walls

Section contains requirements for wall anchorage.

12.14.7.5 Anchorage of Structural Walls

The wall anchorage requirements have been extended to all structural walls, not just concrete and masonry and the anchorage loads have been revised substantially, and the reference to Section 13.3.1 for structures with diaphragms that are not flexible has been removed, so the forces are per this section. The increased force for flexible diaphragms has been revised. The exception specifying different forces for SDC B has been removed.

The 2009 NEHRP modifications to Sections 12.14.7.5.1 and 12.14.7.5.2 were not incorporated into ASCE 7-10.

12.14.8.1 Seismic Base Shear

Section includes the procedures for determining base shear.

12.14.8.1 Seismic Base Shear

For the determination of effective seismic weight there has been an added provision permitting storage live loads to be neglected it they are small and an added provision for including weights of landscape materials (similar to Section 12.7.2). The spectral response parameters have been revised based on the risk-targeted ground motions.

Revisions to the spectral response acceleration parameter are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, and the comparison will be addressed by the PUC.

12.14.7.5 Drift Limits and Building Separation

Section indicates that drift need not be considered, but provides guidance for determining required building separations (1 percent drift).

12.14.7.5 Drift Limits and Building Separation

Text has been added to indicate that the 1 percent drift could be used for property lines.


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Chapter 13, SEISMIC DESIGN REQUIREMENTS FOR NONSTRUCTURAL COMPONETS

13.1.3 Component Importance Factor

Section defines the conditions under which the importance factor of 1.5 applies.

13.1.3 Component Importance Factor

Egress stairways have been added to the list, and the provisions defining how the requirement apply to hazardous materials have been revised.

13.1.4 Exemptions

Section defines which nonstructural components are exempt from the seismic design provisions.

13.1.4 Exemptions Added to the exemption list is “furniture” (except storage cabinets) and “temporary or moveable equipment.” The provisions for SDC D-F have been reorganized but are the same in substance.

13.1.6 Reference Documents

Section indicates the conditions in which a component designed using a different reference document.

13.1.6 Reference Documents

A provision has been added requiring that the anchorage requirements shall not be less than this Standard (Section 13.4) even where a different reference standard is used.

13.2.2 Special Certification Requirements for Designated Seismic Systems

Section provides requirements for seismic certifications in SDC C-F.

13.2.2 Special Certification Requirements for Designated Seismic Systems

The specific wording of the section has been revised but it appears that the section is substantively similar.

13.3.2 Seismic Relative Displacements

Section contains the requirements for determining relative seismic displacements within or between structures.

13.3.2 Seismic Relative Displacements

The importance factor for earthquake loads on the building structure (not the component importance factor) has been added to the determination of relative displacements.

13.4.1 Design Forces

Section prescribes design forces for component attachments.

13.4.1 Design Forces

For determination of the attachment design forces a limitation that Rp shall not exceed


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6.0 has been added. 13.4.2 Anchors in Concrete or Masonry

Section provides requirements for component attachment anchors installed in concrete.

13.4.2 Anchors in Concrete or Masonry 13.4.2.1 Anchors in Concrete 13.4.2.2 Anchors in Masonry 13.4.2.3 Post-installed anchors in concrete and masonry

The section has been reorganized and split into three subsections for different anchor types. For concrete, the section references ACI 318 Appendix D. For masonry the section references TMS 402, indicates that the anchor shall be governed by a ductile steel element, and provides an exception allowing the attachment rather than the anchor to be the controlling element. For post-installed anchors, the section references ACI 355.2 or “other prequalifications.”

The 2009 NEHRP modification to Section 13.6.5.5 Item 6f has been incorporated into this section of ASCE 7-10.

13.4.5 Power Actuated Fasteners

Section places limitations on the use of power actuated fasteners for component anchorage.

13.4.5 Power Actuated Fasteners

An exception has been added to allow the use of power actuated fasteners for suspended ceilings and distribution systems with relatively light weights.

13.4.6 Friction Clips

Section prohibits the use of friction clips for anchorage attachment.

13.4.6 Friction Clips Section has been modified to allow friction clips in SDC C or B and permits beam and flange clamps for hangers under certain conditions.

13.5 Architectural Components 13.5.1 General

Section references Table 13.5-1 for design coefficients for architectural components.

13.5 Architectural Components 13.5.1 General

Revisions to Table 13.5-1 include removing “stacks” (which are covered in mechanical and electrical systems), changing the Rp factor for “signs and billboards” to 3 from 2.5, and adding a line for “egress stairways not part of the building structure”. The section on cabinets has been revised and “laboratory equipment” as well as


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various shelving systems have been separated from cabinets, but there is not a substantive change since the design factors remain the same.

13.5.6 Suspended Ceilings

Section contains seismic design requirements for suspended ceilings.

13.5.6 Suspended Ceilings

Two exceptions have been added for ceiling systems that are exempt from the specific bracing requirements as long as they are surrounded by or connected to walls or soffits that are braced to the structure.

13.5.6.2 Industry Standard Construction

Section contains requirements common ceiling systems.

13.5.6.2 Industry Standard Construction for Acoustical Tile or Lay-in Panel Ceilings

The scope of the section has been clarified by indicating what specific types of systems are covered, and text has been added to permit seismic qualified systems to be exempt from the requirements of this section.

13.5.6.2.1 Seismic Design Category C

Section provides reference standards for seismic design of suspended ceilings.

13.5.6.2.1 Seismic Design Category C

ASTM 580 has replaced the CISCA standard.

13.5.6.2.2 Seismic Design Categories D through F

Section provides reference standards and additional requirements for seismic design of suspended ceilings.

13.5.6.2.2 Seismic Design Categories D through F

ASTM 580 has replaced the CISCA standard. Many of the additional requirements for SDC D-F have been removed. The substantive impact of these revisions depends on whether or not the deleted requirements are contained in ASTM 580.

Comparison depends on review of new reference standard


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13.5.9 Glass in Glazed Curtain Walls, Glazed Storefronts, and Glazed Partitions 13.5.9.1 General

Section provides requirements for glass in various cladding systems.

13.5.9 Glass in Glazed Curtain Walls, Glazed Storefronts, and Glazed Partitions 13.5.9.1 General

The only potential substantive change are clarifications to the definitions of the c1 and c2 factors in Eq. 13.5-2

13.6 Mechanical and Electrical Components 13.6.1 General

Section provides general requirements, including exceptions, and references Table 13.5-1 for design coefficients for mechanical and electrical components.

13.6 Mechanical and Electrical Components 13.6.1 General

Revisions to Table 13.6-1 include removing “chimneys” (which are covered in architectural systems) and organizational revisions to some distribution systems. The only substantive revision to the distribution systems is that the design coefficients for electrical conduit and rigidly mounted cable trays have been revised to be the same as suspended cable trays (ap = 2.5, Rp = 6.0).

13.6.5.5 Additional Requirements

Section provides requirements for the design of mechanical and electrical component supports that are in addition to those in the previous sections

13.6.5.5 Additional Requirements 13.6.5.6 Conduit, cable tray, and other electrical distribution systems (raceways).

The differences include revisions to the requirements for reinforcement at bolted connections through sheet metal (item 2) and revisions for post-installed mechanical anchors (Item 3). The requirements for electrical distribution systems (Item 6) have been moved to a new section and revised in substance.

The 2009 NEHRP modification to Section 13.6.5.5 Item 6f has been incorporated into Section 13.4.2.3 of ASCE 7-10.


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13.6.7 HVAC Ductwork

Section provides requirements for seismic supports of ductwork, including conditions where specific support design is not required.

13.6.7 Ductwork The exceptions have been reorganized with a few substantive changes including weight limits for ducts and trapeze assemblies and hanger requirements for use with the exception.

13.6.8 Piping Systems

Section provides requirements for seismic supports of piping systems, including conditions where specific support design is not required.

13.6.8 Piping Systems 13.6.8.3 Exceptions

Revisions include moving the exceptions to a new section (13.6.8.3) and the addition of design criteria for conditions where “other applicable material standard or recognized design bases are not used.” In addition to the new locations, the revisions to the exceptions include an item for trapeze assemblies.

13.6.8.1 ASME Pressure Piping Systems

Section indicates that systems designed to ASTM B31 are deemed to comply with this section.

13.6.8.1 ASME Pressure Piping Systems

Text has been added indicating that “materials meeting the toughness requirements of ASTM B31 shall be considered high-deformability materials.”

13.6.8.2 Fire Protection Sprinkler Systems in Seismic Design Category C 13.6.8.3 Fire Protection Sprinkler Systems in Seismic Design Categories D through F

The two sections provide design requirements for fire protection sprinkler piping systems.

13.6.8.2 Fire Protection Sprinkler Piping Systems 13.6.8.2 Exceptions

The two sections in ASCE 7-05 have been reorganized in ASCE 7-10.

Revisions are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, but the matter has been reviewed by the PUC. Per Soules: The difference between the two documents, for the most part, is editorial. Section 13.6.8.2 was modified to exclude the new exceptions listed in 13.6.8.3, thus making NFPA 13 truly a standalone reference document. The intent of the 2009 NEHRP Recommended Seismic Provisions was not changed.


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13.6.8.4 Other Piping Systems

Section refers to Section 13.6.11 for the design of piping systems not designed in accordance with ASTM B31 or NFPA 13.

N/A Section has been deleted. No substantive change since Section 13.6.11 would apply in any case.

13.6.9 Boilers and Pressure Vessels

Section indicates that systems designed to ASME BPVC are deemed to comply with this section and indicates that Sections 13.3.1 and 13.3.2 may be used in lieu of the reference standard.

13.6.9 Boilers and Pressure Vessels

Text has been added indicating that “materials meeting the toughness requirements of ASME BPVC shall be considered high-deformability materials.”

13.6.10 Elevator and Escalator Design Requirements

Section references ASME A17.1 for seismic design requirements.

13.6.10 Elevator and Escalator Design Requirements

Text has been added indicating that the “exceptions of Section 13.6.8.3 shall not apply to elevator piping.”

13.6.10.3 Seismic Switches

Section specifies requirements for seismic switches under certain conditions

13.6.10.3 Seismic Controls for Elevators

Revisions include deleting some requirements for locating the seismic switch, adding ASME A17.1 Section 8.4.10.1.2 as deemed to comply, and adding an exception to the ASME A17.1-specified location for the switch.

13.6.11 Other Mechanical and Electrical Components

Section provides design requirements for components not designed in accordance with a reference standard.

13.6.11 Other Mechanical and Electrical Components

The criteria for mechanical components with hazardous materials have been clarified, but the revisions appear to be not substantive.


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Chapter 14, MATERIAL SPECIFIC SEISMIC DESIGN AND DETAILING REQUIREMENTS 14.1 Steel 14.1.1 Reference Documents

Section includes reference standards for steel systems.

14.1 Steel 14.1.1 Reference Documents

Revisions include updated and added reference standards.

A review of the ASCE 7-10 revisions for structural steel as compared to ASCE 7-05 and the 2009 NEHRP modifications will be addressed by the PUC. Per Malley: Iin Section 14.1.1 of FEMA 750, the changes to AISC 341-10 were essentially identical, with an editorial style change and clarification in AISC 341-10 added to FEMA 750 language.

14.1.2 Seismic Design Categories B and C 14.1.3 Seismic Design Categories D through F

Section includes requirements for structural steel structures by SDC.

14.1.2 Structural Steel 14.1.2.1 14.1.2.2 14.1.2.2.1 14.1.2.2.2

Section has been reorganized and revised.

A review of the ASCE 7-10 revisions for structural steel as compared to ASCE 7-05 and the 2009 NEHRP modifications will be addressed by the PUC.


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14.1.4 Cold-Formed Steel

Section provides reference to AISI NAS and ASCE 8 for design of cold-formed carbon and stainless steel systems, respectively.

14.1.3 Cold-Formed Steel 14.1.3.1 14.1.3.2 14.1.3.3

Section has been reorganized, references updated, modifications to reference standards added.

A review of the ASCE 7-10 revisions for cold-formed steel as compared to ASCE 7-05 and the 2009 NEHRP modifications has been addressed by the PUC. Per Manley: ASCE 7-10 has incorporated all requirements on Cold- Formed-Steel Special Bolted Moment-Frame modifications as passed by the BSSC in the 2009 NEHRP Recommended Seismic Provisions except as follows: In ASCE 7, Section 14.1.3.3.3

(FEMA P750, Section 14.1.4.1.3), the following sentence has been added: “The beams shall have a minimum design thickness of 0.105 in.(2.67 mm).” This is a clarification.

In ASCE 7, Section 14.1.3.3.3 (FEMA P750, Section 14.1.4.1.3), the following subsection has been added: “D1.2.1.1 Single-Channel Beam Limitations. When single-channel beams are used, torsional effects shall be accounted for in the design.” This is a clarification.

In FEMA P 750, Section 14.1.4.1.5 (ASCE 7, Section 14.1.3.3.5), the following two sentences have been deleted: “The design story drift shall not exceed 0.03h, unless approved by authority having jurisdiction. In no case shall the design story drift exceed 0.05h.” This change has the net effect of requiring the CFS-SBMF system to


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meet the ASCE 7 allowable storey drift limits contained in ASCE 7, Table 12.12-1. This change holds the system to a more rigorous standard.

14.1.4.1 Light-Framed Cold-Formed Construction 14.1.5 Prescriptive Framing

Section requires light-framed cold-formed steel construction to be designed in accordance with AISI NAS, AISI GP, AISI WSD, AISI Lateral or ASCE 8. One and two family dwellings are permitted to be designed and constructed in accordance to the provisions in the AISI—PM subject to the limitations therein.

14.1.4 Cold-Formed Steel Light-Frame Construction 14.1.4.2 Seismic Requirements…. 14.1.4.3 Prescriptive ….

Two sections have been reorganized and combined. Previous reference standards for engineered systems have been replaced with AISI S100, Section D4 and where seismic design is required to AISI S213. Reference standard for prescriptive design has been revised to AISI S230.

A review of the ASCE 7-10 revisions for cold-formed steel as compared to ASCE 7-05 and the 2009 NEHRP modifications was addressed by the PUC. See Manley comment on Sec. 14.1.4 above.

14.2 Concrete 14.2.2 Modifications to ACI 318

Section includes ASCE 7 modifications to ACI 318-05.

14.2 Concrete 14.2.2 Modifications to ACI 318

Updated ASCE 7 modifications to ACI 318-08.

A review of the ASCE 7-10 revisions for concrete as compared to ASCE 7-05 but the matter has been addressed by the PUC. Note that Sec. 14.2.4 (validation testing for precast shear walls) which was added to ASCE 7-05 by the 2009 NEHRP modifications was not incorporated into ASCE 7-10. Per Kelly: The changes proposed were adopted without major revision. There are several editorial revisions. Only two technical changes were made. In ASCE 7, Section 14.2.2.4 Intermediate Precast Structural Walls, only wall piers for SDC C are treated as the Provisions proposal intended


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instead of wall piers for SDC C to F. Wall piers for SDC D, E, and F are referred to Section 14.2.2.4 (this is an incorrect pointer and probably is intended to be 14.2.2.5). In Section 14.2.2.7 Foundations, the provision is limited to SDC D, E, and F. This change is consistent with the application of the Foundation section in Chapter 21 of ACI 318, but it is a change from the proposal. Regarding 14.2.3, Proposal 4-3, pile details: This proposal was adopted into ASCE 7-10 without changes.

14.3 Composite Steel and Concrete Structures 14.3.1 Reference Documents 14.3.2 Metal-Cased Concrete Piles

Section includes reference standards and additional requirements for seismic design of composite structures.

14.3 Composite Steel and Concrete Structures 14.3.1 Reference Documents 14.3.2 General 14.3.3 Seismic Requirements for Composite Steel and Concrete Structures 14.3.4 Metal-Cased Concrete Piles

New subsections clarify the use of seismic design standards for composite structures, but this does not appear to be a substantive change.

14.4 Masonry 14.4.3 Classification of Shear Walls 14.4.4 Anchorage Forces

Subsections specify that all masonry walls not isolated from the SFRS shall be considered shear walls and that the ACI 530 wall anchorage equations cannot replace the ASCE 7 anchorage requirements.

14.4 Masonry

Sections 14.4.3 and 14.4.4 have been deleted, so the requirements revert to ACI 530. This does not appear to be a substantive change as long as ACI 530-08 is consistent with the ASCE 7-05 requirements.

Whether or not this is a substantive change depends on the requirements in ACI 530-08. Per Harris: Table 12.2-1 of ASCE 7-10 contains the requirements of AAC as published in the 2009 NEHRP Part 1. The corresponding modifications for Chapter 14.4 (.3) are not included in ASCE 7-10.


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14.4.5.2 Flanged Shear Walls

Section contains modifications to Chapter 1 of ACI 530 include provisions for the width of flanges for flanged shear walls.

N/A The modification for flanged shear walls has been deleted, so the provisions of ACI 530-08 govern.

Whether or not this is a substantive change depends on the requirements in ACI 530-08.

14.4.6.2.3 Maximum Area of Flexural Tensile Reinforcement

Section contains modifications to Chapter 2 of ACI 530 include limits on flexural reinforcement of special masonry shear walls for in-plane loading.

N/A The modification for maximum reinforcement has been deleted, so the provisions of ACI 530-08 govern.


14.4.7.7 Anchor Bolts 14.4.7.8 Nominal Shear Strength of Headed and Bent-Bar Anchor Bolts

Section contains modifications to Chapter 3 of ACI 530 include phi factors for strength of anchor bolts and requirements for nominal shear strength of headed and bent-bar anchor bolts.

N/A The two modifications for anchor bolts have been deleted, so the provisions of ACI 530-08 govern.


14.5 Wood 14.5.3 Modifications to AF&PA SDPWS 14.5.3.1 AF&PA SDPWS, Section 4.3.3.2

Section 14.5.3.1 modifies the provisions for shear walls with different materials applied to the same side of the wall.

14.5 Wood

Section 14.5.3 has been deleted, so the requirements revert to the AF&PA SDPWS-08.

Whether or not this is a substantive change depends on the requirements in SDPWS-08.

Chapter 15, SEISMIC DESIGN REQUIREMENTS FOR NONBUILDING STRUCTURES 15.4.1 Design Basis

Section provides the basis of design for various nonbuilding structures, including structural system types in Tables 15.4-1 and

15.4.1 Design Basis

There have been several substantive revisions to Table 15.4-2. In item #2 of the list, the exception includes an added

Revisions to Table 15.4-2 are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, and the comparison will be addressed by the PUC.


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15.4-2 and a list of design additions and exceptions.

reference standard, ACI 307, for stacks and chimneys.

N/A 15.4.9 Anchors in Concrete and Masonry 15.4.9.1 Anchors in Concrete 15.4.9.2 Anchors in Masonry 15.4.9.3 Post-Installed Anchors in Concrete and Masonry

A new section has been added for anchorage to concrete and masonry. For concrete, the section references ACI 318 Appendix D. For masonry the section references TMS 402, indicates that the anchor shall be governed by a ductile steel element, and provides an exception allowing the attachment rather than the anchor to be the controlling element. For post-installed anchors, the section references ACI 355.2 or other prequalifications.

15.5.3 Steel Storage Racks

Section provides additional seismic design requirements specific to storage racks.

15.5.3 Steel Storage Racks 15.5.3.1 15.5.3.2 15.5.3.3 15.5.3.4 Alternative

Section has been revised and new subsections added with modifications to ANSI/RMI MH 16.1

Revisions to Section 15.5.3 are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, but the matter has been addressed by the PUC. Per Soules: The difference between the Provisions and ASCE 7-10 is that the design of the anchorage for steel storage racks must comply with the new anchorage provisions added in ASCE 7. This is an improvement to the document. The intent of the 2009 NEHRP Recommended Seismic Provisions was not changed.

15.6.2 Stacks and Chimneys

Section provides design requirements for stacks and chimneys

15.6.2 Stacks and Chimneys

Additional design requirements and reference standards have been added.

Revisions are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, but the matter has been


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addressed by the PUC. Per Soules: The requirements in the 2009 Provisions for stacks and chimneys were simplified and improved after consultation with the ACI 307 Committee. The intent of the 2009 NEHRP Recommended Seismic Provisions was not changed.

15.6.5.1 Freeboard

Section includes freeboard requirements for secondary containment systems.

15.6.5.1 Freeboard The minimum freeboard requirement in equation 15.6-1 has been changed to 0.42DSac from 0.50 DSac.

15.7.3 Strength and Ductility

Section provides design requirements for structural members that are part of the lateral support system for tanks and vessels.

15.7.3 Strength and Ductility

The requirements for connections, including anchors to concrete have been revised.

15.7.5 Anchorage

Section provides anchorage requirements for tanks and vessels at grade and supported above grade.

15.7.5 Anchorage The scope of the section has been revised to SDC C-F, and the detailing requirements for anchorage have been revised.

15.7.6 Ground-Supported Storage Tanks for Liquids 15.7.6.1 General

Section provides design requirements for tanks supported on the ground.

15.7.6 Ground-Supported Storage Tanks for Liquids 15.7.6.1 General

An exception has been added permitting a site-specific seismic study for determination of ground motions in certain conditions.

Revisions are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, but the matter has been addressed by the PUC. Per Soules: The difference between the 2009 NEHRP Recommended Seismic Provisions and ASCE 7-10 in this case is purely editorial. The intent of the provisions was not changed.

15.7.6.1.2 Sloshing

Section provides requirements for sloshing of stored liquid.

15.7.6.1.2 Sloshing

The sloshing height in equation 15.7-13 has been changed to 0.42DiIeSac from 0.50 DiIeSac


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15.7.7.3 Reinforced and Prestressed Concrete

Section provides design requirements for concrete water storage and water treatment tanks and vessels.

15.7.7.3 Reinforced and Prestressed Concrete

The modifications to the design forces in ACI 350.3 have been revised and revisions to AWWA D110 and D115 have been deleted.

15.7.8.1 Welded Steel

Section provides design requirements for petrochemical and industrial tanks and vessels storing liquids.

15.7.8.1 Welded Steel

The use of reference standards API 620 and 650 has been clarified with respect to tank pressure.

15.7.11.7 Supports and Attachments for Boilers and Pressure Vessels

Section provides requirements for the supports for boilers and pressure vessels and attachments to the pressure boundary.

15.7.11.7 Supports and Attachments for Boilers and Pressure Vessels

The requirements for anchorage have been revised, including an added reference to Section 15.4.9.

15.7.13 Refrigerated Gas Liquid Storage Tanks and Vessels 15.7.13.1 General

The design of such tanks is beyond the scope of this section, and is addressed in part by various product and industry standards.

15.7.13 Refrigerated Gas Liquid Storage Tanks and Vessels

The section has been revised such that the design of these tanks is subject to the provisions of ASCE 7 as well as being addressed in part by various product and industry standards

Chapter 16, SEISMIC RESPONSE HISTORY PROCEDURES

16.1.3.2 Three-dimensional Analysis

Section includes the requirements for ground motions associated with 3-dimensional analysis.

16.1.3.2 Three-dimensional Analysis

Revisions include additional requirements for near source sites.

Revisions are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, but the matter has been addressed by the PUC. Per Sabelli: This proposal was implemented into ASCE 7-10 fully.

16.1.4 Response Parameters

Section specifies scaling for response parameters.

16.1.4 Response Parameters

Text has been added indicating that drift quantities shall be multiplied by Cd/R and specifies minimum scaling for drifts.


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N/A 16.1.5 Horizontal Shear Distribution

New section indicating that amplification of torsion is not required where accidential torsion affects are included in the dynamic analysis model.

Section 17, SEISMIC DESIGN REQUIREMENTS FOR SEISMICALLY ISOLATED STRUCTURES

17.3.2 Ground Motion Histories

Section specifies procedures for use of response history accelerations.

17.3.2 Ground Motion Histories

Much of the text of this section has been deleted and replaced with a reference to Section 16.1.3.2 for development of time histories.

Revisions to Section 16.1.3.2 will be addressed by the PUC.

Chapter 18, SEISMIC DESIGN REQUIREMENTS FOR STRUCTURES WITH DAMPING SYSTEMS No substantive changes. The 2009 NEHRP revisions to Sections 18.3.1 and 18.3.2 were not incorporated into ASCE 7-10.

Chapter 19, SOIL STRUCTURE INTERACTION FOR SEISMIC DESIGN

19.2.1.1 Effective Building Period And 19.2.1.2

Section includes the method for determining the effective period.

19.2.1.1 Effective Building Period

Table 19.2-1 has been revised. Revisions to Table 19.2-1 are similar in scope to the 2009 NEHRP modifications to ASCE 7-05 but the matter has been addressed by the PUC. Per Crouse: Table 19.2-1 and Figure 19.2-1 in ASCE 7-10 are identical to the Table proposed in the 2009 Provisions Part 1.


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Chapter 20, SITE CLASSIFICATION PROCEDURE FOR SEISMIC DESIGN

No substantive changes

Chapter 21, SITE-SPECIFIC GROUND MOTION PROCEDURES FOR SEISMIC DESIGN

21.2.1 Probabilistic MCE

Section defines procedures for determining probabilistic ground motions.

21.2.1 Probabilistic (MCER) Ground Motions 21.2.1.1 21.2.1.2

Ground motions revised to Risk-Targeted MCER

Revisions are similar in scope to the 2009 NEHRP modifications to ASCE 7-05 but have been addressed by the PUC. See Kircher comments on Sec. 11.1 above.

21.2.2 Deterministic MCE

Section defines procedures for determining deterministic ground motions.

21.2.1 Deterministic (MCER) Ground Motions

Ground motions revised to Risk-Targeted MCER

Revisions are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, 05 but have been addressed by the PUC. See Kircher comments on Sec. 11.1 above.

21.4 Design Acceleration Parameters

Section defines how acceleration parameters are determined where the site-specific procedure is used.

21.4 Design Acceleration Parameters

Text has been added to clarify where the site-specific parameters are used in Chapters 12 and 15. Appears to be a clarification rather than a substantive change.

N/A 21.5 Maximum Considered Earthquake Geometric Mean (MCEG) Peak Ground Acceleration21.5.1 21.5.2 21.5.3

New sections covering geometric mean ground accelerations have been added.

Comparison will be addressed by the PUC.


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Chapter 22, SEISMIC GROUND MOTION AND LONG-PERIOD TRANSITION MAPS

Chapter contains the seismic ground motion maps.

Maps have been revised consistent with the risk-targeted ground motion basis of the Standard.

Revisions are similar in scope to the 2009 NEHRP modifications to ASCE 7-05, and the comparison will be addressed by the PUC.

Chapter 23, SEISMIC DESIGN REFERENCE DOCUMENTS Chapter contains a list of

reference documents for Chapters 11-22.

Many reference documents and relevant sections have been updated.

This comparison does not address reference standard revisions beyond Chapters 11-22. Some of the ASCE 7-10 revisions are consistent with 2009 NEHRP revisions. Per Kelly: ASCE 7-10 has incorporated the reference to ACI 318 as intended by the modification contained in the 2009 NEHRP Recommended Seismic Provisions.

Chapter 11A.1, QUALITY ASSURANCE

11A.1.1 Scope Section indicates the scope of the quality assurance provisions

11A.1.1 Scope An exception has been added to Item 1, excluding steel structures in SDC C that are not specifically detailed for seismic resistance (R=3) from the requirements. Cantilever columns systems are not included in the exception.


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11A.1.3.6 Structural Steel

Section includes specific inspection and testing provisions for structural steel systems

11A.1.3.6 Structural Steel

A general reference to the quality assurance provisions of AISC 341 has been added

11A.1.3.6.1 Continuous Special Inspection

Section requires continuous special inspection for all welding.

N/A Section has been deleted, replaced instead by the welding inspection requirements of AISC 341 per Section 11A.1.3.6.

Whether or note this is a substantive change depends on the inspection requirements of AISC 341

11A.2.5 Base Metal Testing

Section specifies testing requirements for steel base metal thicker than 1.5 inches.

N/A Section has been deleted, replaced instead by the welding inspection requirements of AISC 341 per Section 11A.2.4

Whether or note this is a substantive change depends on the testing requirements of AISC 341

Appendix 11B, EXISTING BUILDING PROVISIONS

No changes to this chapter.

NOTE THAT THE ABOVE INFORMATION ON CHAPTER 11A.1 AND APPENDIX 11B IS NOT TREATED IN THE COMPOSITE MARKUP OF PART 1 OF THE 2009 PROVISIONS.