Figure 1:
Figure 2:
Figure 3:
Figure 4:
Story drifts for buildings with 9 story
| Story | Drift ratios [%] of EBFs model | Drift ratios [%] of CBFs model |
|---|---|---|
| 9 | 0.0075 | 0.0087 |
| 8 | 0.0055 | 0.0075 |
| 7 | 0.0054 | 0.0068 |
| 6 | 0.0051 | 0.0058 |
| 5 | 0.0047 | 0.0058 |
| 4 | 0.0046 | 0.0053 |
| 3 | 0.0044 | 0.0047 |
| 2 | 0.0034 | 0.0039 |
| 1 | 0.0015 | 0.0019 |
Seismic parameters according to American Society of Civil Engineers (2022) and C_O_S_Q_C_ (2017)
| Seismic parameters | Values [-] | According to |
|---|---|---|
| Risk Category | II (offices) | (C.O.S.Q.C., 2017; American Society of Civil Engineers, 2022, Table 1.5-1) |
| Occupancy Importance Factor Ie | 1 | (C.O.S.Q.C., 2017; American Society of Civil Engineers, 2022, Table 1.5-1) |
| Seismic Design Category given that site class D (stiff silty clay soil ) and depends on (0.133 ≤ SD1 < 0.20) | C | (American Society of Civil Engineers, 2022, Table 11.6-2) |
| S1: mapped MCER, spectral response acceleration parameter at a long-period (at a 1.0 s-period), | 0.1 | (C.O.S.Q.C., 2017) |
| SS :mapped MCER, spectral response acceleration parameter at short periods (at a 0.2 s-period), | 0.3 | (C.O.S.Q.C., 2017) |
| SDS : design spectral response acceleration parameter at short periods, | 0.312 | (C.O.S.Q.C., 2017) |
| SD1 : design spectral response acceleration parameter at a period of 1.0 s, | 0.160 | (C.O.S.Q.C., 2017) |
| Damping | 5 % | |
| Response reduction factor (R) | Eccentrically Braced Frames (EBF) =8 | (American Society of Civil Engineers, 2022, Table 12.2-1) |
| Site class | D | (C.O.S.Q.C., 2017) |
| Overstrength Factor, Ω0 | 2 | (American Society of Civil Engineers, 2022, Table 12.2-1) |
| Deflection Amplification Factor, Cd | Eccentrically Braced Frames (EBF) =4 | (American Society of Civil Engineers, 2022, Table 12.2-1) |
Descriptions of primary structural performance levels (S-P Levels) according to American Society of Civil Engineers (2017) and Federal Emergency Management Agency (2000)
| S-P | Description | Overall Damage State |
|---|---|---|
| Immediate Occupancy (IO) | The building is safe to occupy and continues to function with minor damage and only limited cleanup. Repairs are not required before re-occupancy. | Minor yielding may occur in some elements (e.g., brace end zones, beam-end plastic hinges), but no significant strength or stiffness loss is permitted. |
| Life Safety (LS) | The structure is damaged significantly but retains a substantial margin against partial or total collapse. The risk of injury due to structural failure is low. Repair may be required before re-occupancy. | Moderate inelastic deformation is widespread. May involve yielding and minor local buckling of steel members (e.g., beam flanges, column webs) in moment frames or significant yielding in bracing members. |
| Collapse Prevention (CP) | The structure is heavily damaged and may be beyond economical repair, but it maintains its gravity load-carrying capacity. The structure retains no margin against collapse. | Extensive inelastic deformation is permitted. May involve severe local buckling, significant out-of-plane distortion, and fracture of non-load-bearing elements, provided the gravity system remains stable. |
| ||
Story drifts for buildings with 12 story
| Story | Drift ratios [%] of EBFs model | Drift ratios [%] of CBFs model |
|---|---|---|
| 12 | 0.0051 | 0.0065 |
| 11 | 0.0060 | 0.0068 |
| 10 | 0.0089 | 0.0111 |
| 9 | 0.0077 | 0.0084 |
| 8 | 0.0048 | 0.0054 |
| 7 | 0.0044 | 0.0050 |
| 6 | 0.0032 | 0.0045 |
| 5 | 0.0032 | 0.0045 |
| 4 | 0.0029 | 0.0048 |
| 3 | 0.0032 | 0.0054 |
| 2 | 0.0023 | 0.0040 |
| 1 | 0.0012 | 0.0017 |
Structural sections for the building
| Building | Stories | Marginal Columns [mm] | Central Columns [mm] | Beams [mm] | Bracing [mm] | Link [mm] |
|---|---|---|---|---|---|---|
| 9 - story | 1st – 3rd | 740x630/30x45 | 580x470/20x35 | 430x300/18x25 | 490x350/15x20 | 444x220/15x18 |
| 4th – 6th | 610x560/25x40 | 510x480/20x30 | 390x280/15x20 | 464x330/12x18 | 400x200/10x15 | |
| 7th – 9th | 580x480/20x35 | 434x360/18x25 | 350x250/10x15 | 370x260/10x15 | 350x180/10x15 | |
| 12 - story | 1st – 3rd | 610x510/x25x40 | 490x410/20x35 | 350x200/15x25 | 360x260/10x15 | 364x130/10x18 |
| 4th – 6th | 450x410/20x30 | 400x410/15x25 | 310x200/10x15 | 277x240/10x15 | 316x100/8x12 | |
| 7th – 9th | 450x370/15x25 | 394x300/15x18 | 250x180/10x15 | 300x220/10x15 | 280x100/6x10 | |
| 10th – 12th | 400x330/15x20 | 370x280/12x15 | 236x180/8x12 | 276x200/10x12 | 260x100/6x10 |
Displacement (mm) corresponding to damage states for models
| Models | Probability of slight state | Probability of moderate state | Probability of extensive state | Probability of complete state | ||||
|---|---|---|---|---|---|---|---|---|
| at 50% | at 90% | at 50% | at 90% | at 50% | at 90% | at 50% | at 90% | |
| EBFs-12 story | 97 | 100 | 133 | 142 | 181 | 204 | 438 | - |
| CBFs-12 story | 66 | 95 | 123 | 137 | 157 | 167 | 198 | - |
| EBFs-9 story | 115 | 134 | 182 | 226 | 293 | 334 | 640 | - |
| CBFs-9 story | 90 | 92 | 122 | 132 | 203 | 219 | 392 | - |
Damage state thresholds (Federal Emergency Management Agency, 2003)
| Damage state | Damage state thresholds [mm] |
|---|---|
| Slight | Sdds1 = 0.70 x Dy |
| Moderate | Sdds2 = Dy |
| Severe | Sdds3 = Dy + 0.75 (Du - Dy) |
| Complete | Sdds4 = Du |