Steel · Bases, anchors & embedded plates
Cast-in anchor: concrete cone & steel (simplified) calculator
Characteristic cone breakout with projected-area group and edge factors, steel tensile failure, and design resistance with partial factors.
Standard: AS 5216 (CCD method, simplified)
Inputs in the worked example
The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.
| Input | Value | Unit |
|---|---|---|
| Design tension on group | 90 | kN |
| Anchors in tension (one row) | 2 | |
| Effective embedment hef | 200 | mm |
| Spacing | 200 | mm |
| Edge distance (one edge) | 200 | mm |
| Concrete f′c (cylinder) | 32 | MPa |
| Concrete state | Cracked (k1 = 8.9) | |
| Anchor size | M20 | |
| Anchor grade | 4.6/S | |
| γMc concrete | 1.5 | |
| γMs steel | 1.5 |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| Bolt diameter df | 20.00 | mm |
| Bolt tensile strength fuf | 400.0 | MPa |
| Tensile stress area As | 245.0 | mm² |
| Core area Ac (threads) | 225.0 | mm² |
| Shank area Ao | 314.0 | mm² |
| k1 | 8.90 | |
| N⁰Rk,c = k1 √f′c hef^1.5 | 142.4 | kN |
| scr,N = 3 hef | 600.0 | mm |
| A⁰c,N = scr² | 360,000 | mm² |
| Ac,N (row of n anchors, one edge) | 400,000 | mm² |
| ψs,N = 0.7 + 0.3 c/ccr (≤ 1) | 0.900 | |
| NRk,c | 142.4 | kN |
| Design cone resistance NRk,c/γMc | 94.93 | kN |
| Design steel resistance n As fuf/γMs | 130.7 | kN |
| Governing design resistance | 94.93 | kN |
- ✓ Tension ≤ governing resistance
- ✗ Ductile preferred: steel governs
Method, formulas and assumptions
- Bolt diameter df = CHOOSE(3,12,16,20,24,30,36) = 20 mm
- Bolt tensile strength fuf = IF(1=1,400,830) = 400 MPa
- Tensile stress area As = CHOOSE(3,84.3,157,245,353,561,817) = 245 mm²
- Core area Ac (threads) = CHOOSE(3,76.2,144,225,324,519,759) = 225 mm²
- Shank area Ao = CHOOSE(3,113,201,314,452,707,1018) = 314 mm²
- k1 = IF(1=1,8.9,12.7) = 8.9
- N⁰Rk,c = k1 √f′c hef^1.5 = 8.9*SQRT(32)*200^1.5/1000 = 142.4 kN
- scr,N = 3 hef = 3*200 = 600 mm
- A⁰c,N = scr² = 600^2 = 3.600e+5 mm²
- Ac,N (row of n anchors, one edge) = (MIN(200,1.5*200)+1.5*200)*((2-1)*MIN(200,600)+600) = 4.000e+5 mm²
- ψs,N = 0.7 + 0.3 c/ccr (≤ 1) = MIN(1,0.7+0.3*200/(1.5*200)) = 0.9
- NRk,c = 142.4*4.000e+5/3.600e+5*0.9 = 142.4 kN
- Design cone resistance NRk,c/γMc = 142.4/1.5 = 94.933 kN
- Design steel resistance n As fuf/γMs = 2*245*400/1000/1.5 = 130.67 kN
- Governing design resistance = MIN(94.933,130.67) = 94.933 kN
- Simplified: pull-out, splitting, blow-out, shear and supplementary reinforcement are not covered. Use AS 5216 in full for design.
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.