13 48 00.00 26.pdf

SECTION 13 48 00.00 26

SEISMIC RESTRAINT FOR MECHANICAL AND ELECTRICAL EQUIPMENT

PART 1 GENERAL

1.1 SCOPE OF WORK

The work covered in this section consists of furnishing all labor, equipment and materials to select, design, and supply seismic restraints for new equipment provided as part of work performed for Robert S. Kerr Powerhouse. Supply the selected anchors with the associated equipment.

1.2 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

AMERICAN CONCRETE INSTITUTE INTERNATIONAL (ACI)

ACI 318 (2014; Errata 1 2014) Building Code Requirements for Structural Concrete and Commentary

ACI 355.2 (2007) Qualification of Post-Installed Mechanical Anchors in Concrete and Commentary

ACI 355.3R (2011) Guide for Design of Anchorage to Concrete: Examples Using ACI 318 Appendix D

ACI 355.4 (2011) Qualification of Post-Installed Adhesive Anchors in Concrete and Commentary

AMERICAN SOCIETY OF CIVIL ENGINEERS (ASCE)

ASCE 7 (2010; Errata 2011; Supp 1 2013) Minimum Design Loads for Buildings and Other Structures

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)

IEEE 693 (2005) Recommended Practice for Seismic Design of Substations

IEEE Std 628 (2011) Criteria for the Design, Installation, and Qualification of Raceway Systems for Class 1E Circuits for Nuclear Power Generating Stations

1.3 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only or as otherwise designated. When used, a designation following the "G"

*ADDED AM0004*

designation identifies the office that will review the submittal for the Government. Submit the following in accordance with SECTION 01 33 00

SUBMITTAL PROCEDURES:

SD-02 Shop Drawings

Detail Drawings; G, HDC

SD-03 Product Data

Concrete Anchors; G, HDC

Seismic Equipment Certification; G, HDC

SD-05 Design Data

Structural Design Calculations for Seismic Restraints; G, HDC

1.4 DESIGN OF SEISMIC RESTRAINT

1.4.1 General Requirements

Apply the requirements for seismic protection measures described in this section to the equipment and systems below. Accomplish resistance to lateral forces induced by earthquakes without consideration of friction resulting from gravity loads. Existing concrete strength is taken as f'c = 3,000 pounds per square inch (psi).

Submit within 90 calendar days of Notice to Proceed, detail drawings as per paragraphs "EQUIPMENT" and "SYSTEMS." Submit together with Structural Design Calculations for Seismic Restraints.

For detail drawings include catalog cuts, templates, anchorage system including mechanical specifications of anchor bolts, erection and installation details for the items listed. Provide submittals complete in detail; indicate thickness, type, grade, class of metal, and dimensions;

and show construction details, anchorage, and installation. Stamp all drawings with the Professional Engineer (PE) stamp who performs and stamps the calculations required above.

Submit structural design calculations performed by qualified civil or structural engineers who are presently registered professional engineers (PE). The calculations verify the capability of the seismic restraints and of structural members to which seismic restraint are attached for carrying the seismic design loads. The design includes seismic anchorage design and details. Provide all calculations stamped and signed by a PE.

1.4.2 Code Requirements for Equipment Restraint

Complete seismic design for equipment restraint in accordance with Chapter 13, "Seismic Design Requirements for Nonstructural Components," of ASCE 7 with the seismic design force computed as per Section 13.3 "Seismic Demands on Nonstructural Components". Design electrical equipment restraint in accordance with the provisions in IEEE 693, or Section 13.3 of ASCE 7 whichever produces the more adverse seismic effects. For ASCE 7, use a spectral acceleration SDS = 0.126, IP = 1.50, and z/h=1. For IEEE 693, use a seismic qualification level of Moderate.

1.4.3 Code Requirements for Systems Restraint

Complete seismic design for systems restraint in accordance with Chapter 13, "Seismic Design Requirements for Nonstructural Components," of ASCE 7 with the seismic design force computed as per Section 13.3 "Seismic Demands on Nonstructural Components". For ASCE 7, use a spectral acceleration SDS = 0.126, IP = 1.50, and z/h=1. Design restraint of electrical systems to the requirements of IEEE Std 628.

1.4.4 Requirements for Equipment Certification

Design, construct, and assemble all equipment listed in paragraph "Equipment", to be provided under this contract to withstand the seismic forces specified in paragraph "Code Requirements for Equipment Restraint."

Provide Seismic Equipment Certification supported by testing or analysis stating the seismic capability of the equipment.

1.5 EQUIPMENT

Develop the structural design calculations for seismic restraints and detail drawings for the following new equipment provided under this contract in accordance with the requirements of this specification:

(a) Panelboards

(b) MCC's

1.7 DEFINITIONS

Sway Brace. An assembly intended to be attached to piping, conduit, bus, or raceways to resist horizontal earthquake loads.

Four-Way Brace. A sway brace intended to resist differential movement in all horizontal directions.

Lateral Brace. A sway brace intended to resist differential movement perpendicular to the axis of piping, conduit, bus, or raceways.

Longitudinal Brace. A sway brace intended to resist differential movement parallel to the axis of piping, conduit, bus, or raceways.

Undercut anchor. Undercut concrete anchors are bearing-type anchors designed to be installed in cured concrete in a hole with a conical undercut near its blind end.

Expansive anchor. Expansive concrete anchors are designed to be installed in cured concrete in a straight hole. Anchorage relies on an torque-controlled expansion wedge and the friction developed between the drilled hole and the expanded wedge.

Adhesive anchor. Adhesive concrete anchors are designed to be installed in cured concrete in a straight hole drilled with a roto-impact drill. Anchorage relies on a chemical adhesive bond to the threaded rod and to the concrete.

Monolith Expansion Joint. Expansion /contraction joint separating two adjacent, structurally independent monoliths.

PART 2 PRODUCTS

NOT USED

PART 3 EXECUTION

3.1 SEISMIC SWAY BRACING

3.1.1 Sway Bracing Design Requirements

Design and provide sway bracing conforming with the requirements of these specifications for both mechanical and electrical systems. Apply seismic forces both in lateral and vertical directions. Base the design of sway braces on the water filled weight of pipe combined with the seismic forces. Base the design of sway braces for electrical conduit or racewayson the design weight of the completely filled conduit or raceway.

3.1.2 Sway Bracing Required for Systems

Provide sway bracing for all suspended systems with the following exceptions. Provide sway bracing for all piping greater than 2-1/2 inch in diameter, or for piping larger than 1 inch in diameter in boiler rooms or for gas piping, or for all pipe diameters if the piping is used as part of a fire protection system. Provide sway bracing for all conduit larger than 2-1/2 inches in diameter. Provide sway bracing for HVAC ducts larger than 6 square feet in cross sectional area or 28 inches in diameter. Provide sway bracing at junctions, and at horizontal or vertical transitions for electrical service raceways and bus ducts. Sway bracing is not required for piping suspended by individual hangers 12 inches or less in length from the top of the pipe to the bottom of the structure the piping is attached to.

3.1.3 Sway Bracing Required for Equipment

Provide sway bracing for equipment supported from overhead floor or roof structural systems.

3.1.4 Sway Bracing Layout

3.1.4.1 General

Sway bracing consists of transverse, longitudinal, and 4-way braces.

Design piping such that sway bracing attachment and configuration does not interfere with thermal expansion of the piping.

3.1.4.2 Transverse Braces

Provide transverse sway braces for piping and conduit at every fourth hanger for diameter sizes 1/4 through 2-1/2 inches and at every third hanger for pipe diameter sizes 3 inch through 8 inch. Provide tranverse sway braces for bus ducts and electrical raceways at vertical or horizontal transitions. Brace vertical systems at not more than 20-foot intervals and locate bracing above the center of gravity of the item being braced.

3.1.4.3 Longitudinal or Four-Way Braces

Provide longitudinal braces or four-way braces at least once per monolith.

Provide longitudinal or four-way braces at least once per straight length of piping or conduit that is greater than 10-feet in length. Provide four-way sway braces for bus ducts at least once per monolith and at changes in directions. Also provide four-way sway braces for cable trays at changes in directions and TEEs.

3.1.5 Seismic Isolation for Piping Systems

Provide spreaders or rack type hangers between adjacent piping runs to prevent contact during seismic activity whenever pipe surfaces are less than 4-inches apart and at the same interval as sway bracing at an equal distance between sway braces.

3.2 BUILDING OR MONOLITH EXPANSION JOINTS

Do not rigidly attach equipment on each side of a building or a monolith expansion joint. For systems which are rigidly attached on each side of a monolith expansion joint, provide flexible connections or system configurations that are capable of accommodating displacements equal to twice the full width of the joint in both orthogonal directions or a minimum of 2-inches in both orthogonal directions. Do not attach an individual seismic sway brace to the structure on each side of a monolith joint.

3.3 SPREADERS

Provide spreaders between adjacent piping runs to prevent contact during seismic activity whenever pipe or insulated pipe surfaces are less than 4 inches apart. Apply spreaders at same interval as sway braces at an equal distance between the sway braces. If rack type hangers are used where the pipes are restrained from contact by mounting to the rack, spreaders are not required for pipes mounted in the rack.

3.4 CONCRETE ANCHORS

Submit manufacturer's product data within 90 calendar days after receiving the Notice to Proceed. Manufacturer's product data includes but is not limited to detail drawings showing dimensions, material data, allowable loads and detailed installation instructions, and anchor test data in accordance with ICC ES Evaluation Services Reports (ESR).

3.4.1 Limitations on Allowable Fasteners to Concrete

Do not utilize powder actuated fasteners, screw or coil type anchors to secure equipment or systems to the powerhouse. Do not use expansive drop-in threaded insert type anchors to suspend equipment or systems from the powerhouse. Do not use expansion anchors to resist vibratory loads due to rotating machinery. Do not use chemically bonded adhesive anchors to resist pull-out in overhead and wall installations if the adhesive is manufactured with temperature sensitive epoxies and the location is susceptible to effects of a building fire or if the adhesive is unsuited to static tension load application. For chemically bonded adhesive anchors for use in low temperature or under-water applications, provide product data indicating suitability for use and pass on-site installation test(s) under anticipated environmental conditions.

3.4.2 General Requirements for Fasteners to Concrete

Provide anchors at least 1/2 inch in diameter unless otherwise indicated in the plans or this specification section. Provide chemically bonded adhesive anchors with an embedded depth equal to at least 12 times nominal diameter of the bolt. Provide expansive or undercut anchors with a minimum embedded depth of at least 4 inches. Compute anchor capacity as per Chapter 17 of ACI 318 and reduce the anchor capacity to account for the effect of spacing between anchor bolts and the distance between anchor bolt and the nearest concrete edge. Provide anchor test data in accordance with ICC ES Evaluation Services Reports (ESR) for each type and class of concrete anchor verifying the suitability of an anchor for the intended application.

3.4.3 Floor Mounted Equipment

Anchor floor mounted equipment to concrete that is reinforced and integrally connected to the reinforced concrete structure. Intermittent tension developed due to laterally applied seismic force of 1000 pounds (lbs) or less may be resisted with expansive concrete anchors capable of resisting dynamic loading in cracked and un-cracked concrete unless otherwise indicated on the drawings. Resist intermittent tension developed due to laterally applied seismic force greater than 1000 lbs with undercut concrete anchors. Epoxy anchors are permitted in applications where concrete foundation pads are not integrally connected to the reinforced concrete structure. Embedment is only considered to occur in structural concrete Embedment soley in architectural floating slabs and house-keeping foundation pads not integrally connected to the reinforced concrete structure will not be accepted. For anchors installed in an environment subject to water intrusion and freeze thaw cycles, provide epoxy adhesive anchors or alternately use undercut anchors and seal with a flexible sealant reccommended by the anchor manufacturer and as indicated on the drawings and approved by the CO.

3.4.4 Suspended Systems

Secure all sway brace assemblies including the vertical support component(s) to the concrete with undercut anchors. Expansive concrete anchors capable of resisting dynamic loading in cracked and un-cracked concrete may only be used to secure hangers at locations without sway bracing. Suspended piping or conduit may be secured with 3/8 inch minimum diameter anchors for pipe and conduit nominal diameters of 3/8 inch through 2 inch to allow compatibility with piping requirements for threaded rod used as hangers. For systems not required to have sway bracing, secure the system a minimum of every 40 feet with undercut anchors.

3.4.5 Wall Mounted Systems

Secure Wall mounted systems with undercut anchor(s) at least once every 40 feet and when direct tension above 500 lbs develops due to gravity loads or laterally applied seismic force. Wall mounted systems may be secured with expansive anchors capable of resisting dynamic loading in cracked and un-cracked concrete at other locations.

3.4.6 Wall Mounted and Suspended Equipment

Secure wall mounted and suspended equipment with undercut anchors if the equipment weighs 50 lbs and above.

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