Quick Start User's Guide

Load Configuration

For the live load group(s) that are to be reduced, activate the option for “Apply Live Load Reduction” and create load case(s) which are connected to reduced live load group(s). This option is available for the following load groups:
- Regular live loads (IBC - load type = L – Live load, Occupancy type = Regular)
- Heavy and parking garage live loads (IBC - load type = L – Live load, Occupancy type = Heavy load and garages)
- Roof live loads (IBC - load type = Lr – Roof live load)
For each reduced load case, apply loads to the structure. Any type of load can be added, but live load reduction is relevant for surface loads only (i.e. Surface load on 2D member or free surface load) so it is recommended that only surface loads exist in reduced load cases.
Load cases which contain reduced live loads must be included in load combinations. Additionally, the load combination should be included in a result class to be included in the check/design of composite members (Note: when project contains composite members, load combinations and a result class are automatically generated)

Input or review settings for entire project in setup and add settings for individual members in member data. (To access Live load reduction service, in main service tree, under Load cases, Combinations select Live load reduction).
Setup inputs control to which members live load reduction gets applied and how columns are handled (continuous or not) in the project. Member data inputs allow for specific values to be entered for influence areas or reduction factors (overriding calculated values) as well as how individual columns are handled.

Run analysis when project is ready.
The program will automatically calculate the reduction factor(s) for each eligible member and apply the reduction factor(s) to the live load(s) accordingly. Reduction factors are calculated based on the influence area (for regular and heavy/garage live loads) or tributary area (for roof live loads) or may entered manually in member data. To see the tributary and influence area(s) of each member as well as the reduction factor(s), click Live load reduction – results within the live load reduction service tree. Within the property menu specify the live load group as well as the value of interest, and select refresh. A full table of parameters for the load group selected can be found by selecting Table results.
Reduced live loads are available for AISC steel and composite checks. If the combination or result class specified for the check contains a reduced live load, the internal force and deflection values used in the check reflect the reduced values

Special consideration should be given to only include loads which are intended to be reduced in a load group which is set for reduction. Since live load reduction is only applicable for uniform surface loads, only uniform surface loads should be included. The program will apply reduction factors to every load (uniform surface or otherwise) in a load group which meets reduction eligibility.
The program will automatically calculate the magnitude of the surface load in a reduced live load group. This is used to compare to specified limits and warn as needed (<100 psf for regular live loads, >100 psf for heavy live loads, and between 12 and 20 psf for roof live loads). The program calculates the magnitude by using an average of all surface loads in a load group. This means that the average surface load calculated may not exactly reflect the actual load on a member. If multiple surface loads of varying magnitude exist in the same model, it may be best to put these loads in different load groups. For live and heavy loads, if the average is greater than or less than the limit, the program simply warns the user. However, for roof live loads, if the average is less than 12 psf, it will adjust the reduction limits so that when multiplied by the average surface load, the value is not less than 12 psf.