Bearing Capacity Factor Dependent on Cohesion given Ultimate Bearing Capacity Calculator

Bearing Capacity Factor Formula:

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

Ultimate Bearing Capacity (q_fc):

kN/m²

Unit Weight of Soil (γ):

kN/m³

Depth of Footing (D_footing):

Bearing Capacity Factor (N_q):

Width of Footing (B):

Bearing Capacity Factor (N_γ):

Cohesion in Soil (C):

kPa

Bearing Capacity Factor (N_c):

1. What is Bearing Capacity Factor Dependent on Cohesion?

Definition: This calculator determines the bearing capacity factor (N_c) that depends on soil cohesion, given the ultimate bearing capacity and other soil parameters.

Purpose: It helps geotechnical engineers and foundation designers evaluate the bearing capacity of cohesive soils for foundation design.

2. How Does the Calculator Work?

The calculator uses the formula:

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

Where:

\( N_c \) — Bearing capacity factor dependent on cohesion
\( q_{fc} \) — Ultimate bearing capacity in soil (kN/m²)
\( γ \) — Unit weight of soil (kN/m³)
\( D_{footing} \) — Depth of footing in soil (m)
\( N_q \) — Bearing capacity factor dependent on surcharge (±5%)
\( B \) — Width of footing (m)
\( N_γ \) — Bearing capacity factor dependent on unit weight (±5%)
\( C \) — Cohesion in soil (kPa)

Explanation: The formula calculates N_c by isolating it from the general bearing capacity equation.

3. Importance of Bearing Capacity Factor

Details: N_c is crucial for determining the bearing capacity of cohesive soils, which affects foundation design and safety factors.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. The bearing capacity factors (N_q and N_γ) typically have ±5% variability.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical range for N_c?
A: For cohesive soils, N_c typically ranges from 5.14 (for pure clay) to higher values for mixed soils.

Q2: Why are N_q and N_γ marked with ±5%?
A: These factors have inherent variability depending on soil conditions and empirical relationships.

Q3: How do I determine cohesion (C) for my soil?
A: Cohesion is determined through laboratory tests like unconfined compression tests or field vane shear tests.

Q4: What if I get a negative result?
A: Check your input values. Negative results typically indicate invalid input combinations.

Q5: How accurate is this calculation?
A: The calculation is theoretically accurate but depends on the accuracy of your input parameters.