Columns and Base Plates may be designed per requirements of five different codes including Allowable Stress Design (ASD), Load and Resistance Factor Design (LRFD), Canadian (CAN/CSA - S16.1 - 94), British (BS5950:1990 or 2000) and Eurocode. For more information about design codes see the Design Codes Section in the RAM Steel Column documentation. To set the design codes:

• Select Criteria > Steel Design Codes.
• Select AISC 360-05 LRFD (BS 5950:2000) for the Column and Base Plate Steel Design Codes.
• Click [OK] .

The Gravity Column program uses trial groups to optimize column sizes. In the Modeler, columns are assigned shape (I, HSS, Pipe), material strength and orientation. The design of the columns is performed by selecting the lightest adequate column size from a maximum of three column groups.

Column groups are identified by the section depth in the designation (e.g. W12, UC254, etc.). The program will select the lightest column from the available column groups which are defined in the Column Design Table.

• Select Criteria > Trial Group Defaults.
  
• Check to use each of the three trial groups. If you want to consider fewer options, uncheck one of the Trial groups on the left.
• For each shape there are a number of trial groups available to choose from.
• For US models, select the trial groups listed in the figure above. For SI models using the RAMUK tables, select the following:
  
• Click [OK].

If any changes are made to the trial groups, you will receive a message asking if you want to assign new trial groups to existing column lines.

• Click [Yes].