Free Tool · EN 1997-1 §6.8 · EN 1992-1-1 · Pad Footing Reinforcement
Pad Foundation Design
Pad footing design per EN 1997-1 §6.8 and EN 1992-1-1. Flexural reinforcement (working-stress method), shear check, and crack width summary for isolated square and rectangular pad footings.
| Required As (mm²/m) | 337 mm²/m |
| Provided As (mm²/m) | 565 mm²/m |
| Selected rebar | H12@200 |
| Shear check V_Ed / V_Rd | V_Ed/V_Rd = 0 → PASS |
| Crack width w_k (mm) | w_k = 0.158 mm |
| Utilization | 60% |
FAQ
1. How is the reinforcement calculated?
Flexural reinforcement is calculated using the EN 1992-1-1 §6.1 working-stress method (alternative to the more complex stress-block approach). The required area of steel As = M_Ed / (0.87·f_yk·z), where z ≈ 0.9·d is the internal lever arm. Minimum reinforcement is 0.26·f_ctm/f_yk·b·d per §9.2.1.1.
2. What is the minimum cover?
EN 1992-1-1 Table 4.3N specifies minimum cover for XC2 (carbonation) exposure: 25mm for C25/30 and 30mm for C20/25. For groundwater or aggressive soil, increase to XD/XF classes. Nominal cover c_nom = c_min + Δc_dev where Δc_dev = 10mm.
3. When is shear reinforcement required?
If V_Ed ≤ V_Rd,c (concrete shear capacity without shear reinforcement), no shear links are needed. V_Rd,c = 0.12·k·(100·ρ_l·f_ck)^(1/3)·b·d. If V_Ed > V_Rd,c, increase footing thickness or add shear links.
4. What crack width limit applies?
EN 1992-1-1 Table 7.1N gives crack width limits: 0.4mm for XC1 (dry interior), 0.3mm for XC2/XC3/XC4 (wet/moderate), 0.3mm for XD1/XD2/XS1. The simplified crack formula w_k = 0.3·k_c·k·(0.6·f_ctm/E_s)·(h-d)/ρ is used.