Cohesion of Soil depending on Shape Factors Calculator

Cohesion Formula:

\[ C = \frac{q_f - (\sigma' \times N_q + 0.5 \times \gamma \times B \times N_\gamma \times s_\gamma)}{s_c \times N_c} \]

Ultimate Bearing Capacity:

Effective Surcharge:

Bearing Capacity Factor (Surcharge):

Unit Weight of Soil:

N/m³

Width of Footing:

Bearing Capacity Factor (Unit Weight):

Shape Factor (Unit Weight):

Shape Factor (Cohesion):

Bearing Capacity Factor (Cohesion):

Cohesion of Soil: Pa

1. What is Cohesion of Soil depending on Shape Factors?

Definition: This calculator determines the cohesion of soil based on ultimate bearing capacity, effective surcharge, soil properties, and shape factors.

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:

\[ C = \frac{q_f - (\sigma' \times N_q + 0.5 \times \gamma \times B \times N_\gamma \times s_\gamma)}{s_c \times N_c} \]

Where:

\( C \) — Cohesion of soil (Pa)
\( q_f \) — Ultimate bearing capacity (Pa)
\( \sigma' \) — Effective surcharge (Pa)
\( N_q \) — Bearing capacity factor for surcharge
\( \gamma \) — Unit weight of soil (N/m³)
\( B \) — Width of footing (m)
\( N_\gamma \) — Bearing capacity factor for unit weight
\( s_\gamma \) — Shape factor for unit weight
\( s_c \) — Shape factor for cohesion
\( N_c \) — Bearing capacity factor for cohesion

3. Importance of Soil Cohesion Calculation

Details: Proper cohesion estimation ensures stable foundation design, slope stability analysis, and earthwork construction safety.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. Factors marked with ±5% indicate typical variability in these values.

5. Frequently Asked Questions (FAQ)

Q1: What is typical cohesion range for soils?
A: Clay soils: 10-200 kPa, silt: 5-50 kPa, sand: 0-10 kPa.

Q2: How do shape factors affect cohesion?
A: Shape factors account for different footing geometries (square, circular, rectangular) affecting bearing capacity.

Q3: What if my soil has no cohesion?
A: For cohesionless soils (sand), use appropriate bearing capacity formulas that don't include cohesion terms.

Q4: How accurate are these calculations?
A: Results are theoretical estimates - always verify with field tests for critical projects.

Q5: Can I use this for shallow and deep foundations?
A: This formula is primarily for shallow foundations. Deep foundations require different analysis methods.