V. GB 50011-2010 Static Seismic - Case1
Calculate the base shear and its distribution along the height using the equivalent lateral force method in GB 50011-2010.
Details
- height = 3× 4m = 12m
- plan dimension X = 4m
- plan dimension Z = 5m
- Frequency of seismic event: Frequent
- Classification of seismic design: Group 2
- Seismic design intensity: 8
- Site class: II
- Equivalent gravity load factor for horizontal seismic action: 0.85 (default in STAAD.Pro)
- Damping ratio, ζ = 0.05 (default in STAAD.Pro)
The section of all members is HW300X300, and the seismic weight for each floor is assumed as 280 kN applied as joint weight of 70 kN to nodes 2, 3, 5, 6, 8, 9, and 11 to 16. S
Validation
The effective weight of the structure:
The structure period (as calculated by STAAD.Pro, Tcalc = 0.685s
The max value of the horizontal seismic influence for a frequent
earthquake
with intensity of 8, ɑmax = 0.16 (Table 5.1.4-1)
The characteristic period, Tg = 0.4s (Table 5.1.4-2)
The power index of the curvilinear decrease section:
The damping adjustment factor:
The horizontal seismic influence coefficient corresponding to the fundamental period of the structure:
The characteristic value of the total horizontal seismic action of the structure:
Additional seismic action factors at the top of the building δn = 0.08×T + 0.01 = 0.065
Additional horizontal seismic action applied at top of the building ΔFn = δn × FEk = 0.065 × 70.69 = 4.59 kN
Characteristic value of horizontal seismic action applied at the ith mass:
| Story Level |
Gi
(kN) |
Hi
(m) |
GiHi
(kN·m) |
GiHi/ΣGiHi |
Fi
(kN) |
ΔFn
(kN) |
Vi
(kN) |
|---|---|---|---|---|---|---|---|
| 3rd | 280 | 12 | 3,360 | 0.5 | 33.053 | 4.59 | 37.633 |
| 2nd | 280 | 8 | 2,240 | 0.333 | 22.030 | 59.633 | |
| 1st | 280 | 4 | 1,120 | 0.167 | 11.015 | 70.687 | |
| Σ | 840 | 6,720 | 1 |
| Story Level | Lateral Load (kN) |
Gravity Load (kN) |
λ (%) |
λmin
(%) |
Adjustment Factor |
|---|---|---|---|---|---|
| 3rd | 37.633 | 280 | 13.44 | 3.2 | 1 |
| 2nd | 59.633 | 560 | 10.65 | 3.2 | 1 |
| 1st | 70.687 | 840 | 8.42 | 3.2 | 1 |
Results
| Result Type | Reference | STAAD.Pro | Difference | Comments | |
|---|---|---|---|---|---|
| Story Shear, Fi (kN) | 1st | 11.015 | 10.971 | negligible | |
| 2nd | 22.030 | 21.943 | negligible | ||
| 3rd | 37.633 | 37.476 | negligible | ||
| Base Shear, V (kN) | 70.687 | 70.390 | negligible | ||
STAAD.Pro Input File
The file C:\Users\Public\Public Documents\STAAD.Pro 2024\Samples is typically installed with the program.