Load Combination for Assessment

 

 

 

Define the ULS and SLS load combinations to be used for the assessment checks using the result output from different type of analysis, i.e., construction stages, static analysis, moving loads, etc.

 

 

 

From the Main Menu select Rating > Bridge Rating Design > CS454/19 > PSC Bridge > Load Combinations for Assessment

 

 

 

Load Combination

A list of load combinations to be used for assessment

Name

Assign name to the load combination.

Limit State

Specify whether this load combination should be used for ULS or SLS assessment.

Combination Type

Specify the combination type with reference to the combinations 1 to 4 as set in CS454/19 (See Appendix A).

Gamma_f3

Specify the partial factor for load effects to be used for the given load combination.

Description

Add any comments relevant for the load combination.

Copy into Assessment Load Combination

Create a new load combination that is a copy of an existing one.

Copy into General Load Combination

Copy selected load combination from this list (Load Combinations for assessment) to the General Load Combinations (Results> Load Combinations> General).  This function can be used to check results for given Assessment Load Combinations as these combinations are not directly available to checks results in the GUI or table results.  Each load combination copied will generate three cases in the general load combination as below:

  • <Comb.Name>(Dead Load):  Represents the contribution of static loads only

  • <Comb.Name>(Live Load):  Represents the contribution of traffic loads only

  • <Comb.Name>:  A copy of assessment load combination representing the full load

Static Load Cases and Factors (Gamma_fL)

List the load cases and output which should be included in the combination

Static Load Cases

Choose the relevant load cases and output to be included in the load combination.

Factor

Set the factor to be used for each load case in the given load combination.

Moving Load Cases and Factors (Gamma_fL)

Select the moving load case to be included in the combination and the factors for the same.

Auto MVL Case

Select this option when 'Auto Live Load Combination' is used in a moving load case with ALL Model 2 from CS454/19 and special vehicle form BD86.

For these load cases, the software will calculate the contribution of the special vehicle and the associated standard vehicle and calculate the reserve factors accordingly for the assessment checks.

For such load cases, the Auto Live Load Combination is switched on and the partial factors for load effects gamma_fL are included in the moving load case analysis.  For this reason, the factor section is locked and set to 1, in order not to double count the gamma_fL factor.

Other MVL Case

Under this option, any moving load case in which the Auto Live Load Combination is switched off can be used in the combination. Generally, this can be used when assessment check is performed by any special vehicle alone. Therefore, the reserve factor is calculated for the special vehicle and not for the accompanying standard vehicle.

For this option, the factor is unlocked and the partial factor (gamma_fl) for live load needs to be specified.