Question
How to check whether the column is Sway or Non sway column as per IS 456 : 2000?
Answer
To determine whether a reinforced concrete (RC) column in a frame is sway or non-sway, we need to evaluate its stability coefficient (θ) or stability index (Q), as the effective length factor differs for sway and non-sway frames. This can be done in GEN using the Stability Coefficient option by selecting the IS 16700 : 2023 code.
According to Clause 7.3.10 of IS 16700 : 2023, the stability coefficient (θ) is defined as follows.
By setting the Response Reduction Factor (R) to 1.0 in the given equation, it becomes equivalent to the stability index (Q) specified in Annex E, E1 of IS 456 : 2000.
where,
The procedure to determine this in GEN is outlined below.
- Navigate to Results Tab > Results Tables > Story > Check Parameter and set the code to IS 16700 : 2023.
- Go to Results Tab > Results Tables > Story > Stability Coefficient.
- Choose the Load Case/Combination for which you want to assess the stability coefficient.
- In the dialog box, input the Response Reduction Factor as 1.0 and set the Allowable Limit to 0.04.
- Select the Vertical load cases from the drop-down menu and assign the appropriate scale factors to consider the total vertical force.
- Finally, choose the preferred Story Drift Method for evaluation.
- The Stability Coefficient Table will be displayed, showing the evaluated stability coefficient for each story.
- If the remark is "NG", it indicates that the story behaves as a Sway Frame; If the remark is "OK", it is classified as a Non-Sway Frame.