Table 6: The values of maximum relative drifts of floors obtained for two-, six-, and fifteen-story frames of flexural type, strengthened with X-bracing system type and strengthened with off-diagonal bracing system type undergoing the earthquakes of Naghan, Tabas, and El Centro (from left to right).
(a)

Floor (Interstory drift) (cm) (Naghan/Tabas/El Centro)
X-bracing system
2-ST6-ST15-ST

10.250.160.210.620.61.40.950.60.8
20.10.090.120.70.831.710.90.450.4
30.81.151.930.750.391.00
41.452.411.681.470.511.1
50.721.520.791.681.412.1
60.510.890.461.931.50 2.6
70.760.953.01
80.932.11.76
90.812.052.51
100.752.51.12
110.61.630.93
120.720.950.81
130.580.710.6
140.490.450.48

150.330.20.23

(b)

Floor (Interstory drift) (cm) (Naghan/Tabas/El Centro)
Off-diagonal bracing system
2-story6-story15-story

10.40.280.352.751.92.65.13.14.93
20.240.120.21.761.242.11.92.033.1
30.850.430.61.711.472.08
41.461.051.41.631.21.43
50.770.520.71.040.981.76
60.680.30.50.980.81.45
71.450.772.5
82.530.630.23
90.81.510.2
100.712.331.49
110.71.51 0.7
120.621.060.32
130.410.430.11
140.280.410.1

150.140.320.06

(c)

Floor (Interstory drift) (cm) (Naghan/Tabas/El Centro)
(flexural)
2-story6-story15-story

10.30.20.272.951.682.931.40.070.9
20.180.10.191.051.982.853.10.511.8
32.481.852.332.41.71.93
41.491.081.452.10.613.91
51.20.91.211.90.532.85
60.80.580.861.850.422.7
71.610.432.53
81.420.941.98
91.230.831.45
101.20.92.9
112.313.41.95
121.861.951.43
131.031.081.32
140.680.811.11

150.340.710.95