Optimal Seismic Intensity Measure Selection for Isolated Bridges under Pulse-Like Ground Motions

Table 2

Characteristics of the four isolated girder bridge types.

Bridge type	Height (m)	Column section size (m)	Span length (m)	First order period (s)	Rayleigh damping parameters
					α0	α1
MCBG	4	1.8 × 1.8	35	0.80	0.3927	0.0064
	6			0.84	0.3762	0.0066
	8			0.91	0.3471	0.0072
	10			1.02	0.3110	0.0080
	12			1.17	0.2720	0.0092
	14			1.35	0.2362	0.0106
	16			1.56	0.2047	0.0122
	18			1.8	0.1775	0.0141
	20			2.06	0.1551	0.0161
MBBG	4	1.5 × 1.5	30	0.71	1.7453	0.0014
	6			0.76	1.1635	0.0017
	8			0.83	0.8055	0.0019
	10			0.94	0.6100	0.0020
	12			1.09	0.4760	0.0022
	14			1.28	0.3762	0.0029
	16			1.49	0.3050	0.0037
	18			1.74	0.2513	0.0048
	20			2.00	0.2130	0.0058
CIGB	4	1.5 × 1.5	25	0.54	2.0943	0.0011
	6			0.58	1.3368	0.0013
	8			0.67	0.9240	0.0015
	10			0.78	0.6829	0.0017
	12			0.94	0.5150	0.0022
	14			1.12	0.4054	0.0029
	16			1.33	0.3272	0.0037
	18			1.56	0.2720	0.0046
	20			1.82	0.2293	0.0057
SIGB	4	1.2 × 1.2	35	0.57	0.5511	0.0045
	6			0.64	0.4947	0.0051
	8			0.75	0.4245	0.0059
	10			0.91	0.3491	0.0072
	12			1.11	0.2964	0.0084
	14			1.35	0.2371	0.0105
	16			1.62	0.1976	0.0126
	18			1.91	0.1675	0.0149
	20			2.23	0.1434	0.0174