in ASCE 7-22, they have imposed a limitation of using the second approach for RSA in case the TIR (Delta max/ delta avg) is more than 1.6

@Eng.tarekyoussef

5 ай бұрын

The limitation in ASCE 7-22 on using the second approach for RSA when the Torsional Irregularity Ratio (TIR) exceeds 1.6 indicates the importance of considering structural behavior accurately. It's worth noting that the second method, involving physically offsetting the mass, could potentially amplify the effects of accidental torsion for some buildings with torsional first modes. In my opinion, engineers should not adopt any approach blindly. They need to conduct a thorough investigation to determine which approach is more logical and accurately predicts the real response of the structure.

@ronykhadra3173

4 ай бұрын

@@Eng.tarekyoussef if TIR exceeds 1,6 and a RSA is required, i think that it is ok to compute the Ax from the ELF procedure and then override the eccentricities in the response spectrum; however, this would require defining U1 and U2 as 2 separate load cases to be able to assign eccentricites for each direction, where applicable; Then, in the combinations, we can use 100% of one direction and 30% of the other; this is not very much recommended since it is better to use U1 and U2 in the same load case so the structure will be oscillated in the principal axis; so whatever we do has its limitations

thanks you eng. tarek really i am very happy to watch these videos , little videos on internet have an excellent and beneficial information. please keep doing well

@Eng.tarekyoussef

7 ай бұрын

You're welcome! I'm glad to hear that you found the videos helpful and enjoyable.

Thanks for all ur education videos☺️

@Eng.tarekyoussef

7 ай бұрын

You're welcome!

Thanks for this usefull tutorial

@Eng.tarekyoussef

5 ай бұрын

You're welcome. Glad it was helpful

Please share Excel. Also, can you also do a full video with an example design of multiple towers in a building in ETABS?

@Eng.tarekyoussef

7 ай бұрын

drive.google.com/drive/folders/1WWyrqs8OaJbvIjkEqigb8ki_FDQmfauO?usp=sharing

if our Ax value comes out to be more than 3 (lets say 4) then do we need to change our structural system in order to reduce the Ax value or should we just take it 3 and design accordingly?

@Eng.tarekyoussef

5 ай бұрын

When the Ax value exceeds 3, it means the structure is at risk of instability due to torsional forces. To ensure safety, it's crucial to follow code requirements closely. If Ax is too high, structural changes are needed to reduce torsional effects and maintain stability.

Thanks a lot for everything. Are you thinking of continuing?

@Eng.tarekyoussef

4 ай бұрын

Yes, soon

Hi, Tarak .. Did you have the updated Excel file to include the ACSE7-16 in your axel sheet? since the value of the Fa and Fv are changed?

@Eng.tarekyoussef

4 ай бұрын

Hello Ahmad. Not yet updated to ASCE 7-16. I am using ASCE 7-10 in my excel sheets.

Torsion amplification should late in the same time of p delta effect or not Thank you

@Eng.tarekyoussef

4 ай бұрын

In my opinion, examining torsion amplification after incorporating the P-Delta effect in the analytical model is the optimal approach. The P-Delta effect accounts for the geometric nonlinearity caused by the interaction between axial loads and lateral displacements. Once this effect is considered, assessing torsion amplification becomes relevant as it captures how lateral displacements induce additional torsional moments, particularly in asymmetric or eccentrically loaded structures. By addressing the P-Delta effect first, the analytical model can provide a more comprehensive understanding of the structure's behavior under lateral loads, including torsional responses.

الشرح رائع لكن الكلام سريع مع من لا يتقن اللغه الاجنبيه... جزاكم الله خيرا

@Eng.tarekyoussef

6 күн бұрын

شكرا جزيلا على ملاحظتك. يمكنك إبطاء سرعة الفيديو لمتابعة الشرح بشكل أفضل