HILTI NFPA 13 Seismic Bracing Anchor Load Tables Instruction Manual
- October 30, 2023
- HILTI
Table of Contents
HILTI NFPA 13 Seismic Bracing Anchor Load Tables Instruction Manual
HILTI MECHANICAL ANCHORS AND CAST-IN ANCHORS FOR SEISMIC BRACING IN ACCORDANCE WITH NFPA 13
Hilti post-installed mechanical anchors and single point cast-in-place anchors are common, cost effective methods for attaching both structural and non- structural elements to concrete base materials. Non-structural elements, such as fire sprinkler pipes; electrical conduit and cable trays; heating, ventilation and air conditioning (HVAC) equipment and ductwork are especially suited for Hilti anchoring systems.
For fire sprinkler pipe applications, Hilti anchors have been effectively used for many years to support the gravity loaded hangers as well as the sway bracing for resisting the lateral and vertical motion resulting from seismic loads.
While Hilti anchors can be designed and installed to support gravity loads of the pipe through the attachment of the hanger to the concrete, this document will focus on the design of the anchorage to attach the sway brace assembly to the concrete structure. Contact Hilti for more information related to Hilti anchors to support the vertical pipe hanger.
In a seismic event the earthquake forces are resisted by the transverse and longitudinal sway bracing and the sway braces will transfer the loads through a fastener that is attached to the concrete. In general, the capacity of the fastener in concrete is dictated by a design per ACI 318-19 Chapter 17, and the design of the sway brace components is dictated by NFPA 13-16 Section 9.3.5 (which references ACI 318-11) and NFPA 13-19 Section 18.5 (which references ACI 318-14).
Note: For simplicity, this document will reference the 2016 NFPA-13 and 2019 NFPA-13 document sections.
This document will not cover the design of the components of the pipe support hangers or sway bracing. Rather, this document will provide the maximum horizontal load that can be applied to the sway brace, Fpw, based on the Hilti fastener type and embedment depth, fastener load capacity, the concrete strength and configuration, the sway brace to fastener connector (seismic hinge) geometry, and the brace angle. See Figure 2 on the following page. Fpw does not consider the adequacy of the seismic hinge or other components of the sway bracing or vertical hanger. The design engineer of record must ensure all of these components are suitable for the application and design loads.
This document is a supplement to the Hilti North American Product Technical Guide, Volume 2, Anchor Fastening Technical Guide, Edition 21 (PTG Ed. 21). Please refer to the publication in its entirety, which is available at www.hilti.com or www.hilti.ca, for complete details including data development, product specifications, general suitability, installation, corrosion and spacing and edge distance guidelines, for the Hilti anchoring systems noted within.
Horizontal earthquake load design per NFPA-13
The maximum horizontal earthquake load, Fpw that will not exceed the allowable capacity of the anchor, can be derived from NFPA 13-16 Eq. A.9.3.5.12.2a and NFPA 13-19 Eq. A18.5.12.2a:
Design Tables for Pre-calculated Horizontal Earthquake Load
The design tables starting on page 8 determine the maximum horizontal load, Fpw, that will satisfy NFPA 13-16 Eq. A.9.3.5.12.2a and NFPA 13-19 Eq. A18.5.12.2a, for various Hilti post-installed and cast-in anchors used in conjunction with various seismic brace swivel attachments to attach the sway brace to concrete.
Notes :
- Tallow and Vallow used as the calculation basis for Fpw in the tables are determined from a strength design calculation according to ACI 318-19 Ch. 17 and converted to allowable values per NFPA 13-16 A.9.3.5.12.8.3(D) and NFPA 13-19 A18.5.12.7.3(D).
- Anchor calculation assumes cracked concrete condition and seismic design category C through F.
- Minimum edge distance noted in tables assumes a single anchor with one nearby edge with the shear load perpendicular toward the edge. For an anchor in a corner, the distance to the edge parallel to the direction of the shear must be at least 1.5 times the minimum edge distance noted in the table.
- Minimum spacing distance noted in tables assumes two anchors in the middle of the concrete with no edge distance reductions.
- Seismic brace swivel attachment prying factors noted in the tables are from data published according to the following documents
- Hilti MQS-SP-L-1/2″ and MQS-SP-T-1/2″ seismic hinge prying factors taken from Hilti Statement on the Prying Factors in regard to Hilti Seismic hinge (all sizes) technical document, dated November 18, 2019.
- TolcoTM Figure 909, 910, and 980 swivel brace attachment prying factors taken from Seismic Bracing Anchor Load Charts B-Line series technical publication, given by Tolco on March 1st, 2021.
- Prying factors for the Afcon AF075, AF076, AF077, AF771 and AF700 were taken from ASC’s Part Info Sheets for AF075, AF076, AF077, AF771 and AF700 downloaded May 7th, 2021.
- The above noted documents are subject to change. Contact Hilti for copies of the reference documents noted above.
- Contact Hilti for copies of the reference documents noted above.
- TOLCOTM trademark is owned by Eaton Corporation plc.
- AFCONTM trademark is owned by ASC Engineered Solutions.
- Prying factors are provided that give the highest value for the given angle category. The corresponding value of Pr and Fpw will be conservative for the other angles within the angle category.
- For angle categories D to I, the angle, , is selected that leads to the highest value for the applied shear load, V. The corresponding value of Fpw will be conservative for the other angles within the angle category. = 30° for Angle D and G, = 45° for Angle E and H, and = 60° or 75° for Angle F and I.
- Fpw does not consider the adequacy of the seismic hinge or other components of the sway bracing or vertical hanger. The design engineer of record must ensure all components are suitable for the application and design loads.
- Values in tables are applicable for noted concrete compressive strength and for concrete with higher compressive strengths.
- For applications outside of the above noted parameters, contact Hilti for assistance.
Design Example :
We will use a carbon steel 1/2-in. diameter x 3-1/4-in. effective embedment depth Hilti KWIK Bolt TZ2 (KB-TZ2) expansion anchor to attach a Hilti seismic lateral brace into 3,000 psi normal weight concrete. We will assume the concrete is cracked for the seismic design. We will assume the anchor is in the middle of a concrete slab (no edge or anchor spacing influence). We will use a Hilti MQS-SP-L-1/2″ seismic hinge with a brace angle of 45 degrees (Angle B) attached to the underside of the concrete. Prying factor for this specific hinge in angle category B is 1.580.
The LRFD tension and shear capacity of the KB-TZ2 is determined through a calculation per ACI 318-19 Ch. 17 based on the design variables from ICC-ES ESR-4266. A design using the Hilti PROFIS Engineering design software yielded the following LRFD capacities (design is performed in cracked concrete with seismic reduction factors per ACI 318-19 17.10.5.4):
CONTENTS
Maximum allowable pipe horizontal load, F (lb) carbon steel pw
Hilti KWIK Bolt TZ2 in 3,000 psi normal weight cracked concrete1
Maximum allowable pipe horizontal load, F (lb) carbon steel pw
Hilti KWIK Bolt TZ2 in 4,000 psi normal weight cracked concrete1
Maximum allowable pipe horizontal load, F (lb) carbon steel pw
Hilti KWIK Bolt TZ2 in 5,000 psi normal weight cracked concrete1
Maximum allowable pipe horizontal load, F (lb) carbon steel pw
Hilti KWIK Bolt TZ2 in 6,000 psi normal weight cracked concrete1
Maximum allowable pipe horizontal load, F (lb) carbon steel Hilti KWIK Bolt
TZ2 in the soffit of pw
3,000 psi or 4,000 psi lightweight concrete over metal deck — 2-in and 3-in
W-deck profiles1,2
Maximum allowable pipe horizontal load, F (lb) carbon steel pw
Hilti KB1 in 3,000 psi normal weight cracked concrete1
Maximum allowable pipe horizontal load, F (lb) carbon steel pw
Hilti KB1 in 4,000 psi normal weight cracked concrete1
Maximum allowable pipe horizontal load, F (lb) carbon steel pw
Hilti KB1 in 5,000 psi normal weight cracked concrete1
Maximum allowable pipe horizontal load, F (lb) carbon steel pw
Hilti KB1 in 6,000 psi normal weight cracked concrete1
Maximum allowable pipe horizontal load, F (lb) carbon steel
Hilti KB1 pw **in the soffit of 3,000 psi or 4,000 psi lightweight concrete
over metal deck — 2-in and 3-in W-deck profiles1,2**
Maximum allowable pipe horizontal load, F (lb) pw
Hilti KCM-WF and KCM-PD in 3,000 psi normal weight cracked concrete1,2
Maximum allowable pipe horizontal load, F (lb) pw
Hilti KCM-WF and KCM-PD in 4,000 psi normal weight cracked concrete1,2
Maximum allowable pipe horizontal load, F (lb) pw
Hilti KCM-WF and KCM-PD in 5,000 psi normal weight cracked concrete1,2
Maximum allowable pipe horizontal load, F (lb) pw
Hilti KCM-WF and KCM-PD in 6,000 psi normal weight cracked concrete1,2
Maximum allowable pipe horizontal load, F (lb) Hilti KCM-MD in the soffit of 3,000 psi pw or 4,000 psi lightweight concrete over metal deck 2-in and 3-in W-deck profiles1,2,3
Maximum allowable pipe horizontal load, F (lb) pw
Hilti KCC-WF in 3,000 psi normal weight cracked concrete with grade 105 or
A193 B7 threaded rod1
Maximum allowable pipe horizontal load, F (lb) pw
Hilti KCC-WF in 4,000 psi normal weight cracked concrete with grade 105 or
A193 B7 threaded rod1
Maximum allowable pipe horizontal load, F (lb) pw
Hilti KCC-WF in 5,000 psi normal weight cracked concrete with grade 105 or
A193 B7 threaded rod1
Maximum allowable pipe horizontal load, F (lb) pw
Hilti KCC-WF in 6,000 psi normal weight cracked concrete with grade 105 or
A193 B7 threaded rod1
Maximum allowable pipe horizontal load, F (lb) Hilti KCC-MD in the soffit of 3,000 psi or 4,000 psi pw lightweight concrete over metal deck 2-in and 3-in W-deck profiles with grade 105 or A193 B7 threaded rod1,2
In the US:
Hilti, Inc.
7250 Dallas Parkway, Suite 1000, Plano, TX 75024
Customer Service: 1-800-879-8000
en español: 1-800-879-5000
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In Canada:
Hilti (Canada) Corporation
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Oakville ON | L6H 0J8
Canada
Customer Service: 1-800-363-4458
Fax: 1-800-363-4459
Hilti is an equal opportunity employer.
Hilti is a registered trademark of Hilti, Corp. ©Copyright 2022 by Hilti, Inc.
The data contained in this literature was current as of the date of publication. Updates and changes may be made based on later testing. If verification is needed that the data is still current, please contact the Hilti Technical Support Specialists at 1-800-879-8000. All published load values contained in this literature represent the results of testing by Hilti or test organizations. Because of variations in materials, on-site testing may be necessary to determine performance at any specific site. Printed in the United States.
January 2022
References
- Power Tools, Fasteners and Software for Construction - Hilti Canada
- Power Tools, Fasteners and Software for Construction - Hilti USA