Applies To
	Product(s):	STAAD Advanced Concrete Design
	Version(s):	All
	Environment:	N/A
	Area:	Concrete Design
	Subarea:	IS 456:2000
	Original Author:	Bentley Technical Support Group

Design of a concrete Long Column as per IS:456-2000 code requires compliance with Notes 1, 2 and 3 of Clause 39.7.1 of this code. To account for the terms “Braced” and “Unbraced” as described in these notes, STAAD.Pro has a design parameter termed as “BRACING” for this code.

 

The available options of the BRACING parameter are –

 

0:            The column is braced about both axes (Default).

1:            The column is unbraced about major axis, but braced about minor axis.

2:            The column is unbraced about minor axis, but braced about major axis.

3:            The column is unbraced about both axes.

 

As per Note 2 of Clause 39.7.1, the additional moment (as calculated by Cl 39.7.1) is added to an initial moment equal to the sum of 0.4 Mu1, and 0.6 Mu2, where Mu2 is the larger end moment from analysis and Mu1 is the smaller end moment from analysis (assumed negative if the column is bent in double curvature). In no case shall the initial moment be less than 0.4 Mu2 nor the total moment including the initial moment be less than Mu2. For unbraced columns, the additional moment shall be added to the end moments.

 

BRACING 0:        Initial moments are calculated and added to the Additional moments about both axis. This is also the default value of this parameter.

BRACING 1:        Initial moment is calculated about minor axis and is added to the Additional moment about minor axis.

BRACING 2:        Initial moment is calculated about major axis and is added to the Additional moment about major axis.

BRACING 3:        No Initial moments are calculated.

 

If the BRACING parameter is not assigned, the program will treat the column as braced about both axes.