Unit Weight of Soil given Strip Footing and Bearing Capacity Calculator

Unit Weight of Soil Formula:

\[ \gamma = \frac{q_s - (1 \times C_{st} \times N_c + \sigma_{strip} \times N_q)}{0.5 \times N_\gamma \times B_{strip} \times 1} \]

Bearing Capacity:

Cohesion of Soil:

Bearing Capacity Factor (Cohesion):

Effective Surcharge:

Bearing Capacity Factor (Surcharge):

Bearing Capacity Factor (Unit Weight):

Width of Footing:

Unit Weight of Soil (N/m³):

1. What is Unit Weight of Soil given Strip Footing and Bearing Capacity?

Definition: This calculator determines the unit weight of soil based on bearing capacity factors and strip footing dimensions.

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

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \gamma = \frac{q_s - (1 \times C_{st} \times N_c + \sigma_{strip} \times N_q)}{0.5 \times N_\gamma \times B_{strip} \times 1} \]

Where:

\( \gamma \) — Unit weight of soil (N/m³)
\( q_s \) — Bearing capacity (Pa)
\( C_{st} \) — Cohesion of soil (Pa)
\( N_c \) — Bearing capacity factor (cohesion)
\( \sigma_{strip} \) — Effective surcharge (Pa)
\( N_q \) — Bearing capacity factor (surcharge)
\( N_\gamma \) — Bearing capacity factor (unit weight)
\( B_{strip} \) — Width of footing (m)

3. Importance of Unit Weight Calculation

Details: Accurate unit weight determination is crucial for foundation design, slope stability analysis, and earthwork calculations.

4. Using the Calculator

Tips: Enter all required parameters. Most bearing capacity factors have default values based on typical soil conditions.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for bearing capacity factors?
A: For φ=30°: Nc≈30, Nq≈18, Nγ≈20. Values vary with soil friction angle.

Q2: How does cohesion affect the calculation?
A: Higher cohesion values typically result in lower required unit weight for the same bearing capacity.

Q3: What's the significance of footing width?
A: Wider footings distribute load over more area, reducing required unit weight.

Q4: How accurate is this calculation?
A: It provides a theoretical estimate. Field tests are recommended for critical projects.

Q5: Can I use this for non-strip footings?
A: No, this formula is specifically for strip footings. Other shapes require different formulas.