Note that this criterion is not utilized unless the user has selected to consider column slenderness in the Criteria-Analysis dialog. The Effective Length affects the column slenderness calculation in accordance with ACI318-02 (10.12) and BS8110 3.8.1.6.1.

Per ACI 10.13.1 The Effective Length Factor for sway frames will be limited to a value larger than or equal to 1.0 when the nomograph is selected in the Effective Length Factor Criteria dialog box.

The Effective Length Factor can be indicated in one of two ways: entering specific values for the major axis and minor axis or allowing the program to choose these values. To enter Major or Minor axis values for columns, select the Use option and type values in the adjacent field. To have the program calculate the Effective Length Factors based on the Nomograph Values, select the Nomograph Values option. Effective Length Factor can also be set in a column by column basis by selecting Assign-Column Effective Length Factor command. If Use Nomograph (ACI) or Use Sec 2.5:BS8110:Part2 (BS8110) is selected, the effective length will be calculated based on the nomographs of 10.12.3 (ACI) or equations of BS8110:Part2:1985 Section 2.5 (BS8110) depending on if the column is sway or non-sway in the axis being calculated.

Clicking OK will save the settings. Modifying this criteria after an analysis or code check has been performed will invalidate the results of that analysis and/or code check.