ASCE Earthquake Regulation Statement - Weak Story Irregularity
In the Irregularity Report, Weak Story Irregularities are checked and necessary conditions are applied.
Discontinuity in lateral strength–weak story irregularity, is calculated as follows.
The Strength Irregularity Coefficient= ( Str )i / ( Str )i+1 < 0.80
Discontinuity in lateral strength–extreme weak story irregularity, is calculated as follows.
The Extreme Strength Irregularity Coefficient= ( Str )i / ( Str )i+1 < 0.65
In according to article 184.108.40.206, structures assigned to Seismic Design Category E or F that have horizontal irregularity Type 1b of Table 12.3-1 or vertical irregularities Type 1b, 5a, or 5b of Table 12.3-2 shall not be permitted.
In according to article 220.127.116.11, structures with a vertical irregularity Type 5b, as defined in Table 12.3-2, shall not be more than two stories or 30 ft (9 m) in structural height, hn.