Group 4 — Fresh Load Calculations & STAAD Model (G+3 Hostel)
This document provides fresh assumptions and calculations (ignoring previous PDFs) and an
accompanying STAAD input file. All assumptions are stated explicitly so you can modify them if
needed.
1. Geometry & Grid
Plan: 24 m × 16 m; Grid: 6 × 4 bays at 4.0 m. Storey levels at: 0.0, 3.5, 7.0, 10.5, 14.0 m.
2. Fresh Load Assumptions
Dead loads (assumed):
- Slab thickness 150 mm → slab self-weight = 0.15 × 25 = 3.75 kN/m²
- Finishes/services ≈ 1.00 kN/m²
- Total floor DL = 4.75 kN/m²
- Roof DL (waterproofing etc.) = 5.50 kN/m²
Live loads (assumed):
- Typical floor LL (hostel) = 2.00 kN/m²
- Roof LL = 1.50 kN/m²
Wall / parapet:
- External masonry wall = 10.00 kN/m (applied on perimeter beams)
- Parapet at roof = 1.50 kN/m
3. Gravity load totals (numerical)
Floor area = 384.0 m²; Perimeter = 80.0 m.
- DL per floor = 4.75 × 384.0 = 1824.0 kN
- LL per floor = 2.00 × 384.0 = 768.0 kN
- Wall total per typical floor = 10.00 × 80.0 = 800.0 kN
- Roof DL = 5.50 × 384.0 = 2112.0 kN
- Parapet total = 1.50 × 80.0 = 120.0 kN
4. Seismic weight & base shear (fresh IS-based estimate)
Assumed seismic parameters: Z=0.24, I=1.0, R=5.0, Sa/g=2.5.
Design horizontal coefficient Ah = (Z·I·Sa/g) / (2·R) = 0.0600
Seismic weight per typical floor Wi_typ = DL_total + wall_total + 0.25·LL_total
- Wi_typ = 1824.0 + 800.0 + 0.25×768.0 = 2816.000 kN
- Wi_roof = 2112.0 + 120.0 + 0.25×576.0 = 2376.000 kN
Total seismic weight W = ΣWi = 10824.000 kN
Therefore base shear Vb = Ah × W = 0.0600 × 10824.000 = 649.440 kN
5. Vertical distribution of Vb to storey forces (IS 1893)
Using Qi = [Wi·hi² / Σ(Wj·hj²)] × Vb. Compute Wi·hi² for each level:
- Level h=3.5 m: Wi=2816.000 kN → Wi·h²=34496.000 kN·m²
- Level h=7.0 m: Wi=2816.000 kN → Wi·h²=137984.000 kN·m²
- Level h=10.5 m: Wi=2816.000 kN → Wi·h²=310464.000 kN·m²
- Level h=14.0 m: Wi=2376.000 kN → Wi·h²=465696.000 kN·m²
Denominator Σ(Wj·hj²) = 948640.000 kN·m²
Storey lateral forces Qi (total at each level):
- Q1 at h=3.5 m = 23.616 kN → Per-node = 0.674743 kN (distributed to 35 nodes)
- Q2 at h=7.0 m = 94.464 kN → Per-node = 2.698971 kN (distributed to 35 nodes)
- Q3 at h=10.5 m = 212.544 kN → Per-node = 6.072686 kN (distributed to 35 nodes)
- Q4 at h=14.0 m = 318.816 kN → Per-node = 9.109029 kN (distributed to 35 nodes)
6. Load application in STAAD
- Dead loads: SELFWEIGHT Y -1.0 (members) + FLOOR LOAD bands for floor DL/roof DL +
MEMBER UNI GY loads for wall/parapet on perimeter beams.
- Live loads: FLOOR LOAD bands for floors and roof.
- Seismic: JOINT LOAD per node at each level with FX/FZ = Qi / (number of joints at that
level).
7. Load combinations used
1.0 DL + 1.0 LL
1.5 (DL + LL)
1.2 (DL + LL + EQX)
1.2 (DL + LL + EQZ)
1.5 (DL + EQX)
1.5 (DL + EQZ)
0.9 DL + 1.5 EQX
0.9 DL + 1.5 EQZ
8. Files generated
- STAAD input: Group4_Fresh_Model.std
- Load calculation report: Group4_Fresh_Load_Calculations.docx
Both are saved in the working directory.
