Factored Load Combination for Strength Design in ASCE 7-10

April 13, 2018 Abdul Siraj, P.E.

In this post, I will provide a brief overview of the factored load combinations for strength design that are specified in ASCE 7-10, Section 2.3. Before identifying the load combinations, it’s a good idea to review the definitions of parameters used in these strength design load combination formulas.

 

Parameter Definitions

D = Dead Load

E = Earthquake Load

L =Live Load

Lr = Roof Live Load

R = Rain Load

S = Snow Load

W = Wind Load

 

Load Combinations for Strength Design, Formulas

  1. 1.4D
  2. 1.2D + 1.6L + 0.5(Lr or S or R)
  3. 1.2D + 1.6(Lr or S or R) + (L or 0.5W)
  4. 1.2D + 1.0W + L + 0.5(Lr or S or R)
  5. 1.2D + 1.0E + L + 0.2S
  6. 0.9D + 1.0W
  7. 0.9D + 1.0E

 

Load Combinations for Strength Design, Text

  1. 1.4 times dead load
  2. 1.2 times dead load + 1.6 times live load + 0.5 times the maximum of (roof Live Load or snow load or rain load)
  3. 1.2 times dead load + 1.6 times the maximum of (roof Live Load or snow load or rain load) + maximum of (live load or 0.5 times wind load)
  4. 1.2 times dead load + 1.0 times wind load + live load + 0.5 times the maximum of (roof Live Load or snow load or rain load)
  5. 1.2 times dead load + 1.0 times earthquake load + live load + 0.2 times snow load
  6. 0.9 times dead load + 1.0 times wind load
  7. 0.9 times dead load + 1.0 times earthquake load