IS 456:2000 CLAUSE 34 & 31.6

Isolated RCC Footing Design & Punching Shear

Automate pad footing sizing based on soil Safe Bearing Capacity (SBC), two-way punching shear at $d/2$, one-way beam shear at $d$, and flexural reinforcement mesh.

1. Column Load & Soil Capacity

Service Axial Load P (kN)

Safe Bearing Capacity SBC (kN/m²)

Column Width a (mm)

Column Depth b (mm)

2. Footing Depth & Concrete Materials

Overall Depth D (mm)

Clear Cover (mm)

Concrete Grade (fck)

Steel Grade (fy)

3. Bottom Rebar Mesh Selection

Bar Diameter

Center-to-Center Spacing (mm)

Designed Footing Dimensions

Analyzing...

-- m × -- m

Net factored soil pressure: -- kN/m²

Two-Way Punching Shear (at d/2):--

One-Way Beam Shear (at d):--

Critical Bending Moment (Mu):--

Bottom Steel Mesh Provided:--

Footing Plan & Critical Sections

IS 456 Cl. 34

IS 456:2000 Footing Design Methodology

1. Area Sizing

Soil bearing pressure is evaluated at working load plus an assumed 10% self-weight:

A_req = (1.1 * P) / SBC

Width B = √(A_req), rounded to the next 50mm increment.

2. Two-Way Punching Shear (Cl. 31.6)

Evaluated along a critical perimeter located at distance $d/2$ from the column perimeter:

tau_c = ks * 0.25 * sqrt(fck)

$k_s = 0.5 + \beta_c \le 1.0$. If $\tau_v > \tau_c$, increase effective depth $d$.

3. Flexural Reinforcement (Cl. 34.2.3)

Bending moment is evaluated at the face of the column:

Mu = qu * B * ((B - a) / 2)^2 / 2

Minimum reinforcement for footing slabs is 0.12% for HYSD bars ($Fe\ 415/500$).