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Load factors

In the ultimate limit state the loads are multiplied by load factors to give a safety margin. Self-weight has a lower factor than variable loads because it is better known. Under Eurocode 1.2 is often used for self-weight and 1.5 for variable loads.

F_d = \gamma_G\,G_k + \gamma_Q\,Q_k

design load

\gamma_G = 1.2,\ \gamma_Q = 1.5

common load factors

Symbols

$F_d$	design load	kN
$G_k$	characteristic self-weight	kN
$Q_k$	characteristic variable load	kN

Example

$G_k = 100$ kN and $Q_k = 40$ kN:

$F_d = 1.2\cdot 100 + 1.5\cdot 40 = 180$ kN.

The characteristic load is what is actually expected. The design load is what you calculate with.

Practise loads and load combinations for free →

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Part of Building and Structures: Loads and load combinations.