B2_DRAFT_03.8_Section_C_Appendix G_SLAC_Seismic_Design_Specifications.pdf

ENVIRONMENT, SAFETY & HEALTH DIVISION

Seismic Design Specification for Buildings, Structures, Equipment, and Systems

SLAC-I-720-0A24E-001-R007

21 February 2023

DRAFT

Publication Data This document was developed by the Seismic Design program and published by ESH Publishing.

Document Title: Seismic Design Specification for Buildings, Structures, Equipment, and Systems

Original Publication Date: 4 August 1999

Revision Date: 21 February 2023

Effective Date: 1 January 2023

Department: Environment, Safety & Health Division

Document Number: SLAC-I-720-0A24E-001-R007

ProductID: 59 | RevisionID: 2531

URL: https://www-group.slac.stanford.edu/esh/documents/techbas/seismic.pdf

Prepared for the United States Department of Energy under contract DE-AC02-76SF00515

Note The technical content of this revision was authored by

Ralph R. Kerwin, SLAC Fire Marshal

Mark Matthews, Building Official, Building Inspection Office

Bryson Brunette, PE, SLAC Structural / Seismic Authority

The content was reviewed by

Scott DeBarger, Accelerator Directorate

Robert Shane Wells, PE, Facilities and Operations

Lydia J. Young, SLAC Chief Engineer https://www-internal.slac.stanford.edu/esh/docreview/reports/revisions.asp?ProductID=59 https://www-internal.slac.stanford.edu/esh/docreview/reports/revisionhistory.asp?RevisionID=2531 https://www-group.slac.stanford.edu/esh/documents/techbas/seismic.pdf

Executive Summary This document is intended to provide an overview of the requirements for seismic analysis and design of buildings, structures, equipment, and systems that will be constructed and installed at SLAC National Accelerator Laboratory.

SLAC will use the 2022 California Building Code (CBC) for structural design criteria.

21 February 2023 SLAC-I-720-0A24E-001-R007 v

Contents

Publication Data Executive Summary Contents v 1 General Design Requirements 1

1.1 Design Guidance 1

1.2 Modular / Portable Buildings 2

1.2.1 Non-permanent Modular / Portable Buildings 2

1.3 Non-structural Components 2

2 Programmatic / Experimental Equipment Design Requirements 3 3 Approved Concrete Anchors 4 4 Special Design Requirements 4

4.1 Determination and Approval 5

4.2 Temporary Installation of Experimental Equipment 5

5 Seismic Design Map 6

Table 1 Horizontal Earthquake Acceleration Values for Experimental Equipment 3

Table 2 Seismic Ground Motion Values 8

Figure 1 Proximity to San Andreas Fault 6

Figure 2 SLAC Map 7

21 February 2023 SLAC-I-720-0A24E-001-R007 1

1 General Design Requirements SLAC will use the 2022 California Building Code (CBC) for structural design criteria.1

The 2022 CBC adjusts the level of design based on risk categories from I to IV. Most projects at SLAC will be Risk Category II, which provides life safety seismic performance. There are a few exceptions to this risk category, which are clearly identified in the building code. These exceptions include assembly occupancies where more than 300 people congregate (Risk Category III) and essential facilities such as the fire station and emergency operations centers (Risk Category IV), requiring continued operation during and/or after an earthquake. Refer to 2022 CBC, Table 1604.5, for more information.

1.1 Design Guidance

To facilitate the process of designing structures and equipment anchorage, the following issues should be considered when designing for resistance to seismic loads:

Site-specific seismic criteria may be based on values determined in accordance with ASCE 7-20162 as amended by the 2022 CBC, Chapter 16. As an alternative, the seismic criteria may be based on the worst-case values shown in Section 5 of this document for the location of the proposed work.

For all anchors embedded into concrete that resist seismic loading, the cracked concrete provisions of ACI 318-2019,3 Chapter 17, as amended by 2022 CBC, Section 1905.1.8, must be considered.

Post-installed anchors installed into hardened concrete (such as epoxy or expansion anchors) must be designed and installed in accordance with the same cracked concrete provisions using the procedures summarized by the manufacturer's approved ICC-ES report.4 Additional information on post-installed anchors can be found in Section 4 of this document

Anchor design must be governed by ductile yielding of a steel element (anchor or attachment), unless the exceptions of ACI 318-2019, Section 17.10 are met.

Any questions about correct implementation of code requirements for seismic design should be directed to the Building Inspection Office (BIO) and the SLAC structural / seismic authority (SSA) (a licensed structural engineer in the Facilities and Operations Division, responsible for providing guidance on regulations, design review, and recommendations pertaining to structural and seismic engineering issues).

1 The California Building Code (CBC) is codified as Title 24, California Code of Regulations, “California Building Standards Code”, Part 2, “California Building Code” (24 CCR Part 2)

2 American Society of Civil Engineers (ASCE) 7-2016, “Minimum Design Loads for Buildings and Other Structures, including Supplements No. 1,2, and 3” (ASCE 7-2016)

For a list of ASCE standards and errata, see the American Society of Civil Engineers (ASCE).

3 American Concrete Institute (ACI) 318-2019, “Building Code Requirements for Structural Concrete and Commentary” (ACI 318-2019)

For a list of ACI standards, see the ACI Store.

4 International Code Council (ICC) Evaluation Report (ER)

For a list of ICC ERs, see ICC Evaluation Service: Reports Directory.

DRAFT

https://www.dgs.ca.gov/BSC/Codes https://slacprod.servicenowservices.com/kb_view.do?sysparm_article=KB0011928 https://www.asce.org/ https://slacprod.servicenowservices.com/kb_view.do?sysparm_article=KB0011928 https://www.concrete.org/store.aspx https://icc-es.org/evaluation-report-program/reports-directory/

Seismic Design Specification for Buildings, Structures, Equipment, and Systems: 2023

2 SLAC-I-720-0A24E-001-R007 21 February 2023

1.2 Modular / Portable Buildings

Modular/portable buildings that are permanently installed must be designed to meet the same criteria as those installed on a foundation and anchored to meet the criteria for Risk Category II.

1.2.1 Non-permanent Modular / Portable Buildings

Temporary trailers must be anchored with straps to ground designed by a licensed engineer. Conex and Conex with office boxes, installed either on the ground or on piers, must be anchored to the earth with 3-foot stakes at each corner of the boxes. (This requirement does not apply to existing Conex boxes, unless they are moved.)

1.3 Non-structural Components

In compliance with the 2022 CBC, non-structural components (including architectural, mechanical, electrical, and plumbing equipment) and their supports and attachments that are permanently attached to a structure must be designed and constructed to resist the effects of the earthquake motions in accordance with governing building codes. Refer to ASCE 7-2016, Chapter 13, for specific requirements.

ASCE 7-2016, Section 13.1.4, exemptions that apply at SLAC are the following:

1. Furniture as outlined in SLAC BIO Policy: Securing Non-Structural Furniture and Components.5

2. Temporary and movable equipment. See Section 4.2 of this document for further information regarding temporary equipment.

3. Discrete mechanical and electrical components in Seismic Design Categories D, E, or F that are positively attached to the structure are exempted, provided that:

a. The component weighs 400 pounds (1,779 N) or less, and the center of mass is located 4 feet (1.22 meters) or less above the adjacent floor level, and flexible connections are provided between the component and associated ductwork, piping, and conduit, and the component Importance Factor, Ip, is equal to 1.0; or

b. The component weighs 20 pounds or less, in case of a distributed system, weighing 5 pounds per foot or less.

4. Distribution systems in Seismic Design Categories D, E, or F included in the exceptions for conduit, cable tray, and raceways in Section 13.6.5, duct systems in 13.6.6 and piping and tubing systems in

13.6.7.3. Where in-line components, such as valves, in-line suspended pumps, and mixing boxes require independent support, they must be addressed as discrete components and must be braced considering the tributary contribution of the attached distribution system.

Note that these exemptions do not require a designed anchorage or bracing to be reviewed by Building Inspection Office, but all equipment still must be secured in place and/or positively connected to supporting

5 BIO Policy: Securing Non-Structural Furniture and Components (9/6/2017) https://slac.sharepoint.com/sites/ESH/bio/biodocs/SLACBIOPolicy-SecuringFurniture.pdf

21 February 2023 SLAC-I-720-0A24E-001-R007 3 structural element(s) as directed by other applicable ASCE 7-2016 code sections (such as Section 13.2.3 and 13.4), the manufacturer requirements, and building code official (or SSA):

2 Programmatic / Experimental Equipment Design Requirements The following programmatic/experimental equipment and structures must be designed and constructed to resist the effects of earthquake motions in a manner that ensures life safety:

Any structure that personnel can enter, such as radiation hutches and shielding structures:

The seismic design criteria will be met by using the 2022 CBC for seismic design (risk category as appropriate per the 2022 CBC).

Any experimental equipment that weighs more than 400 pounds:

The seismic design criteria will be met by using the 2022 CBC for seismic design. For ground-mounted experimental equipment, use the following strength design load combinations of ASCE 7- 2016 Section 2.3.6, “Basic Combinations with Seismic Load Effects”. (Note: this alternate method is allowed only for equipment assigned to Risk Category II of ASCE 7-2016):

– (1.2) × Dead Load + Ev + Emh + L +(0.2) × Snow Load Equation 6

– (0.9) × Dead Load - Ev + Emh Equation 7

– Ev = 0.2 x SDS x Dead Load Equation 12.4-4a (Ch. 12)

Where “dead load” includes operating live load (where applicable) and “Emh” = effects of horizontal seismic forces, including overstrength factor. The seismic loading is analyzed as an inertial force, so the effects of the horizontal acceleration may include overturning. Refer to Table 1 for horizontal force design coefficients as outlined in ESH Course 1336. Alternatively, design level forces for non-structural components can be generated by California licensed civil engineer as outlined in ASCE 7- 16, Chapter 13.

Table 1 Horizontal Earthquake Acceleration Values for Experimental Equipment

Horizontal Earthquake Acceleration

280 and West, incl. Sector 25 East of 280 Experimental Equipment Structure Type Similar to the Following

0.82 g 0.75 g Elevated tanks, vessels, bins, or hoppers on symmetrically braced legs Horizontal, saddle supported welded steel vessels Flat-bottom ground-supported tanks (steel or fiber reinforced plastic) Steel and reinforced concrete distributed mass cantilever structures Components and systems isolated using neoprene elements

1.03 g 0.92 g Elevated tanks, vessels, bins, or hoppers on unbraced or asymmetrically braced legs

6 ESH Course 133, Seismic Anchorage of Experimental Equipment (ESH Course 133) https://www-internal.slac.stanford.edu/esh-db/training/slaconly/bin/catalog_item.asp?course=133

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Inverted pendulum type structure (except elevated tanks, vessels, bins or hoppers)

Spring isolated components and systems

Note Consideration should be given for equipment that may be relocated or installed in multiple locations to use the higher acceleration from the table above. Contact the Building Inspection Office if you have any questions about what acceleration to use.

In all cases, the anchors and the adequacy of the anchorage to support the design loads must be design-reviewed by a California-licensed civil engineer in conjunction with the SSA.

3 Approved Concrete Anchors Post-installed anchors (anchors installed into existing hardened concrete) must be approved to be installed into cracked concrete and resist seismic loads and have a current ICC-ES report. Where anchorage conditions require an engineered design, it must be performed in accordance with the ICC-ES report and the cracked concrete provisions of ACI 318-2019, Chapter 17.

The overstrength (omega) factor must be applicable for the design of post-installed anchorage of nonstructural components in accordance with ASCE 7-2016, Chapter 13. (See ACI 318-2019, Sections 17.4 and 17.5).

Some commonly used, approved anchors are listed below (intended as examples, not an all-inclusive list):

Epoxy types Hilti: HIT-RE 500 V3, HIT-HY 200 A/R V3 Simpson Strong Tie: SET-XP, SET-3G, AT-XP Dewalt: Pure110+, Pure50+, AC200+, AC100+

Anchor rods and sleeves Hilti: HIS-N, HAS, HIT-Z Simpson Strong Tie: RFB, DeWalt Threaded Rods

Expansion (wedge) anchors Hilti: Kwik-Bolt TZ2, Kwik-Bolt TZ, HSL-3 Simpson Strong Tie: Strong-Bolt 2 Dewalt: Power Stud +SD1, +SD2, +SD4, +SD6

Screw anchors Hilti: KWIK HUS-EZ Simpson Strong Tie: Titen HD, Stainless Steel Titen HD, Titen HD Rod Hanger, Titen HD Rod Coupler DeWalt: Screw Bolt +

Anchors or epoxies not listed above need BIO approval, which will require submission of ES reports and technical data sheets.

4 Special Design Requirements There is the possibility that a project at SLAC will require exceptional seismic performance (higher than would be required per the building code), due to special importance to mission or extreme safety hazard.

21 February 2023 SLAC-I-720-0A24E-001-R007 5

SLAC is subject to Department of Energy Standard DOE-STD-1020-20167 as a non-nuclear facility under Section 2.1 of that standard. Projects that contain significant chemical or toxicological hazards must be designed in accordance with DOE-STD-1020-2016, Section 3, “Criteria and Guidelines for Seismic Design”.

For these projects, the structural design must use the importance factors for Risk Category IV. Only the importance factor is changed; the building code chapters used for structural design would be those that are normally used for the particular structure. Note that for some limit states, DOE-STD-1020-2016, Table 3-1 requires substituting a Response Modification Coefficient “R” that is reduced from the ASCE 7-2016 value.

The imposition of Risk Category IV has a significant design and cost impact, requiring seismic testing for the internal parts of equipment such as electrical panel boards, HVAC units, and racks, in addition to stringent building structural requirements. This category is intended to apply only to those structures and systems that must be fully operable during and immediately after a design-level earthquake.

4.1 Determination and Approval

The decision to identify a project as being critical to safety or mission and assign it to Risk Category IV requires the written approval of the laboratory director. This determination must be made and properly documented, during the initiation and conceptual phase of the project, using the policy and guidelines from DOE-STD-1020-2016, CBC 2022, and ASCE 7-2016.

4.2 Temporary Installation of Experimental Equipment

Experimental equipment (such as electronics racks) installed for the purpose of assembly and testing need not be anchored if it will not remain in that location for more than 180 days and provided it does not have the potential to block egress or pose a threat to life safety in the event of an earthquake. Research groups may opt to anchor certain experimental equipment even in temporary locations due to the value or mission-criticality of the equipment. Please check with the equipment owner and BIO regarding temporary installation of equipment.

7 Department of Energy Standard 1020-2016, “Natural Phenomena Hazards Analysis and Design Criteria for DOE Facilities” (DOE-STD-1020-2016) https://www.standards.doe.gov/standards-documents/1000/1020-astd-2016

6 SLAC-I-720-0A24E-001-R007 21 February 2023

5 Seismic Design Map

Figure 1 Proximity to San Andreas Fault

21 February 2023 SLAC-I-720-0A24E-001-R007 7

Figure 2 SLAC Map

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Table 2 Seismic Ground Motion Values*

ASCE7-2016

Site Class C – Very Dense Soil and Soft Rock Site Class D – Stiff Soil

(from soil report) Site Class D – Default

(no soil report) NEW PREVIOUS

LOCATION LOCATION LAT LONG SS S1 SDS SD1 SDC SDS SD1 SDC SDS SD1 SDC

(g) (g) (g) (g) (g) (g) (g) (g)

37.419 -122.194 2.25 0.82 1.80 0.77 E 1.50 NULL NULL 1.80 NULL NULL

37.418 -122.203 2.30 0.86 1.84 0.80 E 1.53 NULL NULL 1.84 NULL NULL

37.416 -122.210 2.33 0.88 1.86 0.82 E 1.55 NULL NULL 1.86 NULL NULL 5

37.414 -122.229 2.49 0.96 1.99 0.89 E 1.66 NULL NULL 1.99 NULL NULL 10

37.412 -122.239 2.57 1.00 2.05 0.94 E 1.71 NULL NULL 2.05 NULL NULL

SD1 & SDS:

For NULL, see ASCE 7-2016, Section 11.4.8

Note:

Spectral acceleration values for "Default Site Class D" are more conservative than Site Class D values (approximately equal to values for Site Class C).

* Use site specific ground motion data from geotechnical report if available. The SDS and SD1 values for various soil site classes.

1.3 Non-structural Components

5 Seismic Design Map