Seismic Response Study of Tunnels Running underneath a Subway Station in Parallel

Table 4

Surface midpoint acceleration under different conditions.

Set	S (m)	Acceleration amplitude (m/s^2)	R1 (%)
FF18		0.925
SS1		1.174	26.918
ST2	3	0.925	0
ST3	6	0.933	0.864
ST4	12	0.913	−1.29
ST5	18	0.929	0.432
ST6	3	0.927	0.216
ST7	6	0.926	0.108
ST8	12	0.924	−0.108
ST9	18	0.924	−0.108
STS10	3	1.170	26.486
STS12	6	1.167	26.162
STS14	12	1.163	25.729
STS16	18	1.157	25.081
STS11	3	1.157	25.081
STS13	6	1.158	25.189
STS15	12	1.162	25.622
STS17	18	1.160	25.405