Building-specific damage parameters of interest include the median spectral displacement of the Complete Structural Damage state, SdC, and the associated lognormal standard deviation (Beta) factor, βC. Values of βC are given in Table A6-11. Median spectral displacement at the Complete Structural Damage state, SdC, is calculated using Equation (A6-6):
ΔC = interstory drift ratio (of the story with maximum drift) at the threshold of Complete Structural Damage — values of ΔC are given in Table A6-9,
HR = height of building at the roof level, in inches — default values of HR are given in Table A6-3 as a function of the number of stories above grade,
α2 = modal height factor, Alpha 2 — values of α2 are given in Table A6-4, and
α3 = modal shape factor, Alpha 3, relating maximum-story drift and roof drift, values of α3 are given in Table A6-10.