1. What is Depth of Footing given Net Pressure Intensity?

Definition: This calculator determines the required depth of a footing based on the difference between gross and net pressure intensities and the unit weight of the soil.

Purpose: It helps civil engineers and construction professionals design proper foundation depths for structural stability.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( D \) — Depth of footing (meters)
• \( q_g \) — Gross pressure (Pascal)
• \( q_n \) — Net pressure (Pascal)
• \( \gamma \) — Unit weight of soil (N/m³)

Explanation: The difference between gross and net pressure is divided by the unit weight of soil to determine the required footing depth.

3. Importance of Footing Depth Calculation

Details: Proper footing depth ensures structural stability, prevents settlement issues, and accounts for soil bearing capacity.

4. Using the Calculator

Tips: Enter the gross pressure, net pressure, and unit weight of soil. All values must be > 0. The ±5% indicates the acceptable margin of error for these inputs.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between gross and net pressure?
A: Gross pressure includes all loads on the footing, while net pressure is the additional pressure beyond existing overburden pressure.

Q2: How do I determine the unit weight of soil?
A: Through soil testing or using standard values for common soil types (e.g., 18 kN/m³ for dense sand).

Q3: Why is there a ±5% margin indicated?
A: This accounts for typical variations in field measurements and material properties.

Q4: Does this calculation consider frost depth?
A: No, frost depth requirements should be checked separately based on local building codes.

Q5: When would I need to adjust the calculated depth?
A: For special conditions like expansive soils, high water tables, or seismic zones.

Depth of Footing given Net Pressure Intensity Calculator© - All Rights Reserved 2025