Torsional Irregularity Checker (ASCE 7-22)
Check the torsional irregularity of a building from your ETABS, SAP2000, STAAD or RAM results by ASCE 7-22 Chapter 12 (SI units). Paste the ETABS tables (Story Max Over Avg Drifts and Displacements, ETABS 22 or older layouts) or type the values, for up to 50 storeys and 8 load cases.
For every storey and load case the sheet works out the Torsional Irregularity Ratio TIR (maximum over average storey drift) against 1.2 (the single Type 1 of ASCE 7-22), with EXTREME above 1.4, and the amplification factor Ax of 12.8.4.3 (1.0 to 3.0) with the amplified accidental eccentricity. It gives the governing storey and load case in each direction, PASS / CHECK / EXTREME for every storey and case, one overall result (NO TORSIONAL IRREGULARITY, TORSIONALLY IRREGULAR or EXTREME TORSIONAL IRREGULARITY) and a checklist of what the irregularity triggers by Seismic Design Category: 3D model, amplified accidental torsion, drift at the edges, orthogonal load combinations, diaphragm and collector force increase, height limits, redundancy and the mass offset restriction of modal response spectrum analysis. Six live charts show the TIR, Ax and the edge and average drift against the elevation. The ASCE 7-22 provisions follow published secondary sources; the Read Me lists what is still to be confirmed.
Every result is a visible Excel formula with ASCE 7-22 section references; the items taken from secondary sources are listed in the Read Me. Includes the Excel workbook and a worked A4 sample calculation. One licence per engineer or office. Looking for the Philippine code? See the NSCP 2015 edition.
