Comparison of Scaling Ground Motions Using Arithmetic with Logarithm Values for Spectral Matching Procedure

Table 1

Vibration periods of the 3-, 9-, and 20-story structures.

Model	Vibration mode	Periods (s)	Modal mass participation ratio	Cumulative modal mass participation ratio
3-story	1st	1.00	0.828	0.828
	2nd	0.31	0.135	0.963
	3rd	0.16	—	—
9-story	1st	2.15	0.731	0.731
	2nd	0.81	0.109	0.840
	3rd	0.45	0.044	0.884
	4th	0.29	0.019	0.903
20-story	1st	4.11	0.755	0.755
	2nd	1.47	0.115	0.870
	3rd	0.86	0.038	0.908