1. Anchor
Channel Systems
2. HAC
Portfolio
3. HAC
Applications
Allowable Stress Design (ASD)
Design philosophy based on ensuring the service loads do
not exceed the elastic limit. This is accomplished by ensuring
that stresses remain within the limits through the use of safety
factors. The safety factor accounts for all of the uncertainties in
loads and strength (material).
m
R n
³ å L i
FS i = 1
Where:
R n = nominal or design strength (stress, moment, force, etc.) FS
FS= Safety factor 3-4 typically)
L 1 = nominal (or service) value for the i th load component out of
m components
Strength Design
m
f R n ³ å g i L ni
8. Reinforcing
Bar Anchorage
9. Special Anchor
Channel Design
10. Design
Software
Symbols and Notation
D = dead load
D i = weight of ice
6.2.1 ANCHOR CHANNEL LOADING
The design of anchor channels is now based on Strength Design
philosophy. Applied loads shall be factored according to the
applicable building code.
m
f R n ³ å g i L ni
i = 1
Terminology
Load Factors:
E = earthquake load
F = load due to fluids with well-defined pressures and
maximum heights
F a = Flood load
H = load due to lateral earth pressure, ground water
pressure, or pressure of bulk materialsL = live load
L r = roof live load
R = rain loadS = snow load
T = self-straining forceW = wind load
Wi = wind-on-ice determined in accordance with Chapter 10.
Load Combinations ASCE 7-05 — Strength
Design
1. 1.4(D + F)
2. 1.2(D + F + T) + 1.6(L + H) + 0.5(L r or S or R)
3. 1.2D + 1.6(L r or S or R) + ((0.5 or 1.0)*L or 0.8W)
4. 1.2D + 1.6W + (0.5 or 1.0)*L + 0.5(L r or S or R)
Load Combinations: 5. 1.2D + 1.0E + (0.5 or 1.0)*L + 0.2S
Different types of loads can be combined since it can be
applied simultaneously, however they may not be with the same
magnitudes and factors. 6. 0.9D + 1.6W + 1.6H
7. 0.9D + 1.0E + 1.6H
Strength Design philosophy uses load factors to amplify
the magnitude of the calculated loads to account for the
uncertainties involved in estimating the magnitude of different
loads.
6.2.2 LOAD COMBINATIONS
Anchor channels shall be designed using the applicable load
combination. When selecting the required load combination,
it is important to ensure the load combinations are consistent
with the International Building Code used to derive the loads. If
load combinations and derive loads use different IBC versions,
the anchor channel design may result in very unconservative or
conservative results.
Load Combinations ASCE 7-05 — Allowable
Stress Design
1. D + F
2. D + H + F + L + T
3. D + H + F + (L r or S or R)
4. D + H + F + 0.75(L + T) + 0.75(L r or S or R)
5. D + H + F + (W or 0.7E)
6. D + H + F + 0.75(W or 0.7E) + 0.75L + 0.75(L r or S or R)
7. 0.6D + W + H
8. 0.6D + 0.7E + H
11. Best
Practices
12. Instructions
for Use
13. Field Fixes
14. Design
Example
Introduction
Wind design in ASCE 7-10 underwent several major changes.
Wind provisions in ASCE 7-10 follow the form introduced for the
seismic provisions in the 2005 edition. New wind speed maps
that vary by risk category have been introduced. The wind
speeds provided in such maps are applicable for determining
wind pressures for strength design. Therefore, wind pressures
are strength level and the wind load factor was changed to 1.0.
Load Combinations ASCE 7-10 — Strength
Design
1. 1.4D
2. 1.2D + 1.6L + 0.5(L r or S or R)
3. 1.2D + 1.6(L r or S or R) + (L or 0.5W)
4. 1.2D + 1.0W + L + 0.5(L r or S or R)
5. 1.2D + 1.0E + L + 0.2S
6. 0.9D + 1.0W
7. 0.9D + 1.0E
Load Combinations ASCE 7-10 — Allowable
Stress Design
1. D
2. D + L
3. D + (L r or S or R)
4. D + 0.75L + 0.75(L r or S or R)
5. D + (0.6W or 0.7E)
6a. D + 0.75L + 0.75(0.6W) + 0.75(L r or S or R)
6b. D + 0.75L + 0.75(0.7E) + 0.75S
7. 0.6D + 0.6W
8. 0.6D + 0.7E
Where:
∅ = strength reduction factor
Y i = load factor for the ith load component out of n components
R n = nominal or design strength (stress, moment, force, etc.)
L n1 = nominal (or service) value for the ith load component out of
m components
6.2 ANCHOR CHANNEL LOADING
7. Anchor Channel
Design Code
i = 1
6. Loading
Also known as Load and Resistance Factor Design (LRFD).
Design philosophy considers uncertainties in material
properties, construction tolerances, and loads. It incorporates
state-of-the-art analysis and load and resistance factors are
statistically calibrated to ensure a uniform level of safety.
5. Base material
IBC refers to ASCE Standards for the determination of loads
and selection of the required load combinations. Although
some of the load combinations do not change in different ASCE
year, ASCE 7-10 has undergone some important changes.
Special attention shall be paid to the ASCE version used for the
determination of forces and load combinations.
144
6.1 S
TRENGTH DESIGN VS
ALLOWABLE STRESS DESIGN
4. Design
Introduction
Cast-In Anchor Channel Product Guide, Edition 1 • 02/2019
145