Effect of Near-Fault Pulsed Ground Motions on Seismic Response and Seismic Performance to Tunnel Structures

Table 7

Exceeding probabilities under fortification standards responding to different ground motions.

Ground motions	Fortification standards	Normal service	Exceed probability/% available after repairing	Life threatened
Near-fault pulsed ground motions	VIII frequent	55.01	9.12	5.59
	VIII basis	98.93	65.68	57.70
	VIII rare	99.98	91.87	88.77
	VIII extremely rare	100.00	98.24	97.62
Far-field ground motions	VIII frequent	34.96	1.60	0.34
	VIII basis	98.79	54.39	41.32
	VIII rare	99.99	91.91	88.54
	VIII extremely rare	100.00	97.38	96.19