Cohesion of Soil given Depth and Width of Footing Calculator

Cohesion Formula:

\[ C = \frac{q_{fc} - (γ \times D \times N_q + 0.5 \times γ \times B \times N_γ)}{N_c} \]

Ultimate Bearing Capacity (q_fc):

kPa

Unit Weight of Soil (γ):

kN/m³

Depth of Footing (D):

Bearing Capacity Factor (N_q):

Width of Footing (B):

Bearing Capacity Factor (N_γ):

Bearing Capacity Factor (N_c):

Cohesion in Soil (C): kPa

1. What is Cohesion of Soil Calculator?

Definition: This calculator determines the cohesion of soil based on bearing capacity factors, footing dimensions, and soil properties.

Purpose: It helps geotechnical engineers and construction professionals evaluate soil strength for foundation design.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ C = \frac{q_{fc} - (γ \times D \times N_q + 0.5 \times γ \times B \times N_γ)}{N_c} \]

Where:

\( C \) — Cohesion in soil (kPa)
\( q_{fc} \) — Ultimate bearing capacity (kPa)
\( γ \) — Unit weight of soil (kN/m³)
\( D \) — Depth of footing (m)
\( B \) — Width of footing (m)
\( N_q, N_γ, N_c \) — Bearing capacity factors

3. Importance of Soil Cohesion Calculation

Details: Cohesion is crucial for determining soil shear strength, foundation stability, and slope stability in construction projects.

4. Using the Calculator

Tips: Enter all required parameters. Bearing capacity factors typically have ±5% variability. Default values are provided for common soil conditions.

5. Frequently Asked Questions (FAQ)

Q1: What is typical cohesion value for clay?
A: Soft clay: 10-20 kPa, medium clay: 20-40 kPa, stiff clay: 40-75 kPa.

Q2: How do I determine bearing capacity factors?
A: They depend on soil friction angle. Use standard tables or our Bearing Capacity Factor Calculator.

Q3: Why include footing dimensions?
A: Larger footings distribute load differently and affect the bearing capacity equation.

Q4: What units should I use?
A: Consistent units are critical - use kPa for pressure, kN/m³ for unit weight, and meters for dimensions.

Q5: How accurate is this calculation?
A: Theoretical accuracy depends on input precision. Field tests are recommended for critical projects.