Unit Weight of Soil given Shape Factor Calculator

Unit Weight of Soil Formula:

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

Ultimate Bearing Capacity:

Shape Factor (Cohesion):

Cohesion:

Bearing Capacity Factor (Cohesion):

Effective Surcharge:

Bearing Capacity Factor (Surcharge):

Bearing Capacity Factor (Unit Weight):

Width of Footing:

Shape Factor (Unit Weight):

Unit Weight of Soil (N/m³):

1. What is Unit Weight of Soil given Shape Factor?

Definition: This calculator determines the unit weight of soil based on bearing capacity factors, shape factors, and other soil parameters.

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

2. How Does the Calculator Work?

The calculator uses the formula:

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

Where:

\( \gamma \) — Unit Weight of Soil (N/m³)
\( q_f \) — Ultimate Bearing Capacity (Pa)
\( s_c \) — Shape Factor dependent on Cohesion (±5%)
\( C \) — Cohesion (Pa)
\( N_c \) — Bearing Capacity Factor dependent on Cohesion (±5%)
\( \sigma' \) — Effective Surcharge (Pa)
\( N_q \) — Bearing Capacity Factor dependent on Surcharge (±5%)
\( N_\gamma \) — Bearing Capacity Factor dependent on Unit Weight (±5%)
\( B \) — Width of Footing (m)
\( s_\gamma \) — Shape Factor dependent on Unit Weight (±5%)

3. Importance of Unit Weight Calculation

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

4. Using the Calculator

Tips: Enter all required parameters. Default values are provided for typical conditions. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for shape factors?
A: Shape factors typically range from 1.0 to 1.3 for cohesion and 0.8 to 1.0 for unit weight, depending on foundation shape.

Q2: How accurate are the bearing capacity factors?
A: Bearing capacity factors have ±5% uncertainty and depend on soil friction angle.

Q3: What affects cohesion in soils?
A: Cohesion depends on soil type, moisture content, and compaction. Clay soils have higher cohesion than sandy soils.

Q4: How do I determine effective surcharge?
A: Effective surcharge is the vertical stress at foundation level from any overburden or surface loads.

Q5: When would I adjust the width of footing?
A: Footing width is determined by structural loads and soil bearing capacity requirements.