Provide detailed explanation for identification of section as a wall with respect to Depth and Width of member in RCDC

Provide detailed explanation for identification of section as a wall with respect to Depth and Width of member in RCDC

Please note the points below followed in RCDC for design of Columns based on provisions of IS 13920 (2016). This is as per our understanding of the code and based on discussions with some experts on the code –

1. Columns should be B/D >= 0.4 (or D/B <= 2.5 – clause 7.1.2)
2. Columns with as B/D < 0.4 to be designed as per provisions of wall (Clause 7.1.2)
3. Walls to be considered if D/B > 4 (Or B/D <= 0.25) (Clause 10.1.3)
4. As per experts, 2.5 < D/B < 4 should be avoided as these elements exhibit partial wall-column behavior

You would notice that, in RCDC we allow users a bit of flexibility in defining the ratio for differentiation of wall and column. By default, the value is set at 4 as per the provisions of code. We hope this explains, the reason for defining the section to qualify as wall. For example, if you want sections with D/B > 5 to be designed as column. So, in RCDC, you have to set the qualifier for this as 6. This will segregate the cross-sections in 2 categories – 1) All sections with D/B <=6 would be treated as columns, 2) All sections with D/B > 6 would be treated as walls. You would appreciate that; we would not be able to provide this option to be changed for individual member. It would not be possible for us to handle that.