M. To generate load combinations per Eurocode

To generate load combinations for the Strength limit state per Eurocode - Basis of structural design, BS EN 1990:2002+A1:2005 (sometimes referred to as "Eurocode 0").

The load combination generator is capable of creating load combinations per equations 6.10, 6.10a, or 6.10b found in Cl. 6.4.3.2.

These equations specify the following combinations of loads:

\underset{j \geq 1}{Σ} γ_{G, j} G_{k, j} + γ_{p} P + γ_{Q, 1} Q_{k, 1} + \underset{i > 1}{Σ} γ_{Q, 1} ψ_{0, 1} Q_{k, 1}

(6.10)

Alternatively, for the strength limit state, the less favorable of equations 6.10a and 6.10b may be used:

\underset{j \geq 1}{Σ} γ_{G, j} G_{k, j} + γ_{p} P + γ_{Q, 1} ψ_{0, 1} Q_{k, 1} + \underset{i > 1}{Σ} γ_{Q, 1} ψ_{0, 1} Q_{k, 1}

(6.10a)

\underset{j \geq 1}{Σ} ξ_{j} γ_{G, j} G_{k, j} + γ_{p} P + γ_{Q, 1} Q_{k, 1} + \underset{i > 1}{Σ} γ_{Q, 1} ψ_{0, 1} Q_{k, 1}

(6.10b)

where

Gk	=	Permanent actions
P	=	Prestress actions
Qk	=	Variable actions

Note: The effects in each of the above equations are always additive. If any effect is negative (that is, would reduce the final sum), its effect is taken as zero.

On the Utilities ribbon tab, select the User Tools > Euro Code Load Combination Generator tool in the User Tools group.
The Eurocode Combination Generator dialog opens.
Select the Equation Number to use for the generation of load combinations.
(Optional) Specify a Start Combination Number.
Select the Method as either:

Combination to use post-analysis combination of results, which appropriate for linear elastic analysis

or
Repeat Load to generate repeat load cases from the primary load cases, which is appropriate for second order effects and dynamic analysis

(Optional) Specify load Factors for use in the combination equations.

Factor title	Equation notation
Permanent Actions, Gamma G	γ_G
Pre Stress Actions, Gamma P	γ_P
Variable Actions, Gamma Q	γ_Q
Permanent Action Reduction Factor, Xi	ξ
Variable Action Combination Factor, Psi 0	ψ₀

Note: The default values are taken from those provided in EC0.

(Optional) Click Table A1.1 to select one of the recommended values for the Permanent Action Reduction Factor, Psi (ψ₀).

Click Categories to specify in which load action classification each STAAD.Pro load category is to be assigned.

Action	Included Loads
(None)	Loads of this type will not be included in generated load combinations.
Permanent	Gk (permanent) By default, Dead loads are included. Tip: You may also want to include Mass or Gravity load.
Variable	Q (variable) By default, Live, Roof Live, Wind, and Snow are included. Tip: You may also want to include loads such as Seismic, Temperature, etc.
Pre Stress	P (prestress) No loads are included by default in this category. Tip: As STAAD.Pro does not use a load category for prestressing forces, a less-common load category such as Imperfection can be used for this action.

Click Generate Combinations. A confirmation dialog box opens with the status of the export. Load cases are generated with the selection equation and load case number in the title.