1. What is Ground Bearing Pressure?

Ground Bearing Pressure (GBP) is the pressure exerted on the ground by a load. It's calculated by dividing the total weight by the contact area and is typically measured in kPa (kilopascals) or psf (pounds per square foot).

2. How Does the Calculator Work?

The calculator uses the GBP formula:

Where:

• \( GBP \) — Ground bearing pressure (kPa or psf)
• \( W \) — Total weight (kN or lb)
• \( A \) — Contact area (m² or ft²)

Explanation: The formula calculates the pressure distribution by dividing the total load by the area over which it's distributed.

3. Importance of GBP Calculation

Details: Accurate GBP calculation is crucial for foundation design, soil stability assessment, construction equipment selection, and preventing ground settlement or failure.

4. Using the Calculator

Tips: Enter weight in kN or lb, contact area in m² or ft², and select the appropriate unit system. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a safe ground bearing pressure?
A: Safe GBP varies by soil type. Typical values range from 50-400 kPa for different soil conditions. Always consult a geotechnical engineer for specific projects.

Q2: How does GBP differ from soil bearing capacity?
A: GBP is the actual pressure exerted, while bearing capacity is the maximum pressure the soil can withstand without failure. GBP should always be less than the soil's bearing capacity.

Q3: When is GBP calculation most important?
A: Critical for foundation design, heavy equipment operations on soft ground, temporary works, and construction in areas with poor soil conditions.

Q4: How does contact area affect GBP?
A: Larger contact area reduces GBP for the same weight, which is why spread footings and mats are used to distribute loads over larger areas.

Q5: Can GBP be too low?
A: While low GBP is generally safe, extremely low values might indicate inefficient design or oversized foundations that could be optimized.