19- ASCE-7 Amplification of Accidental Torsion with Example- Dr. Noureldin

In this video:
1. Inherent Torsion
2. Accidental Torsion
3. Amplification of Accidental Torsion
4. Example

[@RobiulIslam-pb2st]

When i apllied Amplified accidental eccentricity (Ax is 1.5) ratio in etabs 2017, it has increased the drift ratio more than previous analysis.

[@rafiktaleb1504]

Dear Dr. Mohamed Nouredin,
Thank you for the interesting lecture.
I’m a little confused regarding the last part of the commentary slide (at the very end) regarding torsional amplification when the dynamic analysis method is used.
In my understating for Modal Response Spectrum Analysis (12.9.1) it is not necessary to amplify the torsional effects when accidental torsion is accounted for dynamically by use of mass offset. However, when accidental torsion is accounted for statically by accidental torsional moment, the amplification still applies.
For Linear Response History Analysis (12.9.2), it is required to include accidental torsion by only the use of a mass offset. Therefore, Amplification of accidental torsion is not required

[@murillin186]

Hello Dr. Noureldin. Thank you for the instruction on amplifciation of accidental torsion. I have a question regarding the response spectrum provisions in ASCE that allows for the displacement of the mass by the 5% of accidental torsion. Some softwares such as Etabs allow for mass offset to be done on the mass source. When I use this method I notice that the plan torsion is significantly higher than the static method. Is this appropriate behaviour?