Seismic Behavior of RNC-Isolated Bridges: A Comparative Study under Near-Fault, Long-Period, and Pulse-Like Ground Motions

Table 3

Relative efficiency measure of the four isolation systems based on their influence on the bridge’s internal forces.

	Figure number	Figure description	Number of load cases/figure	Isolation system (ratio^1)				Least efficient^2	Most efficient^3
				LRB	HDR	FPS	RNC
Line 1	Figure 9(a)	Cant. torsion	12 cases	0/0	12/0	0/12	0/0	FPS	HDR
Line 2	Figure 9(b)	Cant. long. moment	12 cases	4/3	1/2	2/6	5/1	FPS	RNC
Line 3	Figure 9(c)	Cant. trans. moment	12 cases	1/4	4/4	2/2	5/2	LRB	RNC
Line 4	Figure 10(a)	Pier long. moment	12 cases	4/4	3/0	1/5	4/3	FPS	HDR
Line 5	Figure 10(b)	Pier trans. moment	12 cases	1/3	2/4	6/3	3/2	LRB	FPS
Line 6	Figure 11(a)	Base shear long.	12 cases	4/2	2/0	1/9	5/1	FPS	RNC
Line 7	Figure 11(b)	Base shear trans.	12 cases	2/1	3/2	1/9	6/0	FPS	RNC

 ¹Ratio of two numbers: the number of load cases per figure in which the isolator was the most relatively efficient among the four types and the number of load cases per figure in which the isolator was the least relatively efficient one.
²The least relatively efficient isolation system (among the four types) in the study of the corresponding figure.
³The most relatively efficient isolation system (among the four types) in the study of the corresponding figure.