Project 2
POST-PROCESSING PHASE
1. Base Pressure and Settlement Check
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Extract Base Pressure from FE model (e.g., PLATE STRESSES → SYY for vertical stress).
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Compare with allowable soil bearing pressure from Project-1.
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Settlement Check: Use soil stiffness modulus and compare total & differential settlements with limits.
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If base pressure or settlement exceeds limits, increase the footprint or thickness of the slab.
EXTRACTION OF DESIGN VALUES
2. Wood-Armer Moments (from FE model post-processing):
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For each plate element:
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Extract Mx, My, and Mxy.
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Use Wood-Armer equations to get:
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Max/Min design moments in short and long directions.
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3. Shear Stress
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Extract Qx and Qy from plate results (usually "SHEAR X" and "SHEAR Y").
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Take maximum and minimum values for design checks.
4. Axial Stress
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Extract Sxx and Syy (in-plane axial stresses).
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Use element thickness to convert to axial forces.
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Calculate design tension/compression if significant.
REINFORCEMENT DESIGN (Excel Spreadsheet)
5. Calculate Reinforcement for Each Element
For each critical FE element:
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From Wood-Armer: Get M (design moment)
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From axial stress: Compute T = stress × area of element
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Assume x = d – cover – ½ bar dia
Then:
M,net = M – T × x
Ast1 = (0.5 fck / fy) × [1 – √(1 – 4.6×M,net / (fck × b × d²))] Ast2 = T / (0.87 × fy) Total Ast,req = Ast1 + Ast2
Inputs in Excel:
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Element ID
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M (kNm)
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T (kN)
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b (width), d (depth)
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fck, fy
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x (lever arm)
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Output: Ast1, Ast2, Ast_total
Sheet Structure: "Reinforcement_Calculator.xlsx"
Input Section (per element)
| Element ID | Element Type | b (mm) | d (mm) | fck (MPa) | fy (MPa) | M (kNm) | T (kN) | x (mm) |
|---|---|---|---|---|---|---|---|---|
| E101 | Short Wall | 1000 | 200 | 30 | 500 | 12.5 | 35.2 | 150 |
Calculated Values
| M,net (kNm) | Ast1 (mm²) | Ast2 (mm²) | Ast Total (mm²) | Ast / m (mm²/m) |
|---|---|---|---|---|
| =M - T×x/10⁶ | see formula | =T/(0.87×fy) | =Ast1 + Ast2 | =Ast_Total × 1000 / b |
⚠ Note: Multiply x by T (in N) → T × x (in N.mm) → ÷ 10⁶ to convert to kNm for
M,net
Key Formulas (in Excel):
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Net Moment:
= [M] - ([T]*[x])/1000000
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Ast1 (Flexure Only):
= (0.5 * [fck] / [fy]) * (1 - SQRT(1 - (4.6 * [M,net] * 10^6) / ([fck] * [b] * [d]^2)))
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Ast2 (Tension Only):
= [T] * 1000 / (0.87 * [fy])
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Ast Total:
= [Ast1] + [Ast2]
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Ast per meter width (optional for slabs):
= [Ast_Total] * 1000 / [b]
Element ID
Element Type
b (mm)
d (mm)
fck (MPa)
fy (MPa)
M (kNm)
T (kN)
x (mm)
M,net (kNm)
Ast1 (mm²)
Ast2 (mm²)
Ast Total (mm²)
Ast / m (mm²/m)
E101
Short Wall
1000
200
30
500
12.5
35.2
150
0
0
0
0
0
CRACK WIDTH CHECK
Ensure crack width ≤ 0.2 mm using:
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BS 8007 or Eurocode 2 formulas
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Inputs: bar dia, spacing, cover, stress in steel, concrete type
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Use semi-empirical formulas or software spreadsheet
REINFORCEMENT DETAILING
6. Draft Reinforcement in CAD
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Base slab: plan + section
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Walls: elevation + vertical/horizontal sections
Details to show:
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Bar sizes, spacing
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Tension and distribution bars
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Cover
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Development length
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Mesh zones (for FE mapping)
If CAD not available, you can:
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Use AutoDrawings, LibreCAD, or hand-drawn + scanned sketch
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Save to DXF/DWG or image formats
