Research Article
Assessment and Code Considerations for the Combined Effect of Seismic Base Isolation and Viscoelastic Dampers
Table 2
Response of model buildings.
| | Models | | | Fixed based | Base isolated | Viscoelastic dampers | Combination |
| | Forth storey | Lateral sway (mm) | Eq-A, secs | 3.1 | 6.3 (25.2) | 0.8 | 6.3 (25.2) | | Eq-B, secs | 7.3 | 94.6 (378.3) | 3.1 | 90.4 (361.5) | | Static equivalent force method | 10.8 | 37.0 (147.8) | 8.4 | 35.8 (143.2) | | Bending moment (kNm) | Eq-A, secs | 43.4 | 5.4 (21.7) | 7.9 | 2.6 (10.5) | | Eq-B, secs | 81.5 | 65.2 (260.6) | 24.1 | 36.5 (145.9) | | Static equivalent force method | 125.7 | 26.0 (103.7) | 88.7 | 14.8 (59.3) | | Drift ratio 10−3 | Eq-A, secs | 0.17 | 0.025 (0.1) | 0.04 | 0.015 (0.06) | | Eq-B, secs | 0.47 | 0.40 (1.6) | 0.17 | 0.24 (0.97) | | Static equivalent force method | 0.73 | 0.15 (0.6) | 0.53 | 0.093 (0.37) |
| | Second storey | Lateral sway (mm) | Eq-A, secs | 1.7 | 6.1 (24.5) | 0.5 | 6.2 (24.7) | | Eq-B, secs | 3.8 | 91.6 (366.2) | 1.8 | 88.6 (354.5) | | Static equivalent force method | 5.5 | 35.8 (143.0) | 4.5 | 35.1 (140.3) | | Bending moment (kNm) | Eq-A, secs | 53.2 | 8.4 (33.5) | 13.8 | 5.4 (21.7) | | Eq-B, secs | 111.7 | 121.3 (485.1) | 52.7 | 77.1 (308.3) | | Static equivalent force method | 159.3 | 48.1 (192.3) | 129 | 31.0 (123.9) | | Drift ratio 10−3 | Eq-A, secs | 0.35 | 0.05 (0.2) | 0.09 | 0.035 (0.14) | | Eq-B, secs | 0.8 | 0.75 (3.0) | 0.37 | 0.52 (2.06) | | Static equivalent force method | 1.2 | 0.325 (1.3) | 0.9 | 0.2 (0.83) |
| | Structural frame | Base shear (kN) | Eq-A, secs | 117.6 | 13.7 (54.6) | 42.9 | 9.6 (38.2) | | Eq-B, secs | 211.7 | 284.0 (1135.8) | 131.8 | 188.2 (752.8) | | Static equivalent force method | 275.2 | 77.5 (310.0) | 320.8 | 77.5 (310.0) | | Reduction factor () | | 8 | 8 (2) | 8 | 8 (2) | | Period of the building () (secs) | | 0.575 | 2.479 | 0.475 | 2.452 |
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Note: time history analyses results were obtained as average of 5 peaks.
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