1. Anchor
Channel Systems
2. HAC
Portfolio
3. HAC
Applications
Option (a) of 17.2.3.4.3 Ductility requirement of tension is
not available for shear because the cross section of the steel
element of the anchor cannot be configured so that steel
failure in shear provides any meaningful degree of ductility.
ASCE 7-10 chapter 13 Table 13.5.1
Locking t-bolt HBC-N with HAC plain profile Serrated t-bolt HBC-T with HAC-T serrated profile
Figure 7.6.4.1: Standard HAC channel with locking t-bolt HBC-C-N. Figure 7.6.4.2 Serrated channel-HAC-T with HBC-T bolts.
• Positive connection via mechanical interlock between channel
lips and t-bolt head
• (4) Notches in channel lip are created by HBC-C-N after
installation torque is applied.
• The ф value is 0.55 for in which periodical inspection is
provided for all t-bolts.
• The ф value is 0.65 for in which continuous inspection is
provided for M16 and M20 t-bolts.
• The steel strength for M12 t-bolts used with continuous
inspection an increased value of 2,021lbs should be used with
ф value of 0.55. • Positive connection via mechanical interlock between channel
lips and t-bolt head.
• Channel comes with pre-made serrations. Installation torque
is lower than the one required for the notched t-bolt.
• The ф value is 0.65 for in which periodical inspection is
• provided for M12 to M20 t-bolts.
• The ф value is 0.75 for in which continuous inspection is
• provided for M12 to M20 t-bolts.
• Historically, longitudinal loads in anchor channels have been
transferred by means of friction. AC232 requires a positive
connection for transferring of the forces.
• Traditionally the longitudinal loads are transferred by means
of friction
• The loads are assumed to be transferred is larger than the
frictional resistance caused by tightening the bolts
• The bolts are fully pretensioned to cause a clamping force
between the connected components, which allows frictional
resistance to develop between them
• The frictional resistance prevents the connected components
from slipping into bearing against the body of the bolt
• To ensure successful performance, the faying surfaces
require special preparation
• The longitudinal load transfer depended on installation and
special inspection on site
• There were no measures that would include into the design
for reduction of capacity
In order to validate the global level of safety or conservatism for
a product application, AC232 section 1.3.2 states that the load
transfer in the longitudinal direction shall not rely on friction.
Where compliance is sought for seismic loading or for static
shear loading along the longitudinal axis of the anchor channel,
the longitudinal loads shall be transferred by a positive load
transfer mechanism.
The anchor channel must be flush with the substrate surface
and installed with specified installation torque to ensure proper
interlock between channel lip and t-bolt.
AC232 – Page 8
Transfer of shear load in the direction of the longitudinal channel
axis from the channel bolt via channel and anchors into the
concrete shall use a positive load transfer mechanism that shall
be capable to ensure safe and effective behavior under normal
and adverse conditions., both during installation and in service.
Factors included are installation conditions in concrete and
torqueing of the channel bolts.
Note:
HAC-30 comes with serrated channel lips. HAC-30 matching
serrated t-bolts are HBC-B.
The transferring of longitudinal forces shall not rely on friction.
The cycling nature of seismic loading combined with the long-
term relaxation of the nut and the high sensitivity to installation
error are some of the major reasons why a positive load transfer
mechanism (a connection that does not rely on friction) is
required.
Ω o Non structural
component
14. Design
Example
Cast-In Anchor Channel Product Guide, Edition 1 • 02/2019
197
Anchor channels provide two options to positively transfer
longitudinal forces; using locking channel bolts with smooth
channel profiles or serrated channels with serrated bolts.
AC232 covers both systems. The load transfer mechanism is
mechanical interlock.
196
ASCE 7-10 chapter 12 Table 12.2.1
13. Field Fixes
Ω o Structural
component
12. Instructions
for Use
Ω o overstrength factor for architectural component can be
obtained from Table 13.5.1 of ASCE 7-10 and for structural
components from Table 12.2.1.
11. Best
Practices
6. (0.9- 0.2SDS) D + ΩoQE + 1.6H
10. Design
Software
5. (1.2+ 0.2SDS) D+ ΩoQE+ L + 0.2S
9. Special Anchor
Channel Design
• Option c) The anchor or group of anchors shall be
designed forthe maximum shear obtained from design
load combinations that include E, with E increased by Ω o .
This seismic provisions intend to ensure anchors resisting
significant seismic forces do not undergo sudden brittle
failure. One way to achieve this is to add sufficient extra
strength to the anchor by design, so that the failure must
occur elsewhere in the system. Increasing the earthquake
inertial load with an overstrength factor Ωo has been included
in the ACI 318-14 standard as one of four possible options for
preventing premature anchor failure. Here ACI refers us back
to ASCE 7-10 load combination 5 and 7 of chapter 12.
8. Reinforcing
Bar Anchorage
• Option b) The anchor or group of anchors shall be designed
for the maximum shear that can be transmitted to the anchors
by a nonyielding attachment.
7.6.4 TRANSFER OF LONGITUDINAL FORCES
7. Anchor Channel
Design Code
• Option a) The anchor or group of anchors shall be designed
for the maximum shear that can be transmitted to the
anchor or group of anchors based on the development
of a ductile yield mechanism in the attachment in flexure,
shear, or bearing, or a combination of those conditions, and
considering both material overstrength and strain hardening
effects in the attachment.
6. Loading
17.2.3.5.3 Anchors and their attachments shall be designed
using one of options (a) through (c):
5. Base material
• Refer to Figure 7.6.3.1 and 7.6.3.2 explaining the requirements
in ACI 318-14 Section 17.2.3.5.3 in figure and in a flow chart.
4. Design
Introduction