Shape Factor Dependent on Cohesion Calculator

Shape Factor Formula:

\[ s_c = \frac{q_f - (σ' \times N_q + 0.5 \times γ \times B \times N_γ \times s_γ)}{N_c \times C} \]

Ultimate Bearing Capacity (qf):

Effective Surcharge (σ'):

Bearing Capacity Factor (Nq):

Unit Weight of Soil (γ):

N/m³

Width of Footing (B):

Bearing Capacity Factor (Nγ):

Shape Factor (sγ):

Bearing Capacity Factor (Nc):

Cohesion (C):

Shape Factor (sc):

1. What is Shape Factor Dependent on Cohesion?

Definition: Shape Factor dependent on Cohesion is defined as the ratio of the limit unit base resistance of a footing of any shape bearing on the soil surface to that of a strip footing on the soil surface.

Purpose: It's used in geotechnical engineering to calculate the bearing capacity of different foundation shapes considering soil cohesion.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ s_c = \frac{q_f - (σ' \times N_q + 0.5 \times γ \times B \times N_γ \times s_γ)}{N_c \times C} \]

Where:

\( s_c \) — Shape factor dependent on cohesion
\( q_f \) — Ultimate bearing capacity (Pa)
\( σ' \) — Effective surcharge (Pa)
\( N_q \) — Bearing capacity factor dependent on surcharge (±5%)
\( γ \) — Unit weight of soil (N/m³)
\( B \) — Width of footing (m)
\( N_γ \) — Bearing capacity factor dependent on unit weight (±5%)
\( s_γ \) — Shape factor dependent on unit weight (±5%)
\( N_c \) — Bearing capacity factor dependent on cohesion (±5%)
\( C \) — Cohesion (Pa)

3. Importance of Shape Factor Calculation

Details: Proper calculation ensures accurate estimation of foundation bearing capacity, which is crucial for structural stability and safety.

4. Using the Calculator

Tips: Enter all required parameters. The bearing capacity factors and shape factors typically have ±5% variability. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical range for shape factor (sc)?
A: For most foundations, sc ranges between 1.0 and 1.3, but can vary based on foundation shape and soil conditions.

Q2: Why do some factors have ±5% notation?
A: These factors are empirically derived and typically have about 5% variability in practical applications.

Q3: How do I determine the bearing capacity factors?
A: They are typically determined from soil properties and foundation geometry using established geotechnical tables or equations.

Q4: What if my cohesion value is zero?
A: This calculator is for cohesive soils. For cohesionless soils, different equations apply.

Q5: How accurate is this calculation?
A: While theoretically sound, actual field conditions may vary. Always consult a geotechnical engineer for critical applications.