1. What is Ground Bearing Pressure?

Ground Bearing Pressure (GBP) is the pressure exerted by a crane's outriggers or tracks on the ground surface. It's a critical safety parameter that determines whether the ground can safely support the crane's weight during lifting operations.

2. How Does the Calculator Work?

The calculator uses the GBP equation:

Where:

• \( GBP \) — Ground Bearing Pressure (kPa)
• \( total\_weight \) — Total weight of the crane including load (kg)
• \( contact\_area \) — Total contact area of outriggers/tracks (m²)

Explanation: The equation calculates the pressure distribution by dividing the total weight by the contact area between the crane and the ground.

3. Importance of GBP Calculation

Details: Accurate GBP calculation is crucial for crane safety, preventing ground failure, ensuring stability during lifting operations, and complying with safety regulations on various job sites.

4. Using the Calculator

Tips: Enter total weight in kilograms, contact area in square meters. Both values must be positive numbers. The calculator will provide the ground bearing pressure in kilopascals (kPa).

5. Frequently Asked Questions (FAQ)

Q1: What is a safe GBP value for typical ground conditions?
A: Safe GBP values vary by ground type: 50-100 kPa for firm ground, 25-50 kPa for soft ground, and below 25 kPa for very soft or unstable ground.

Q2: How do I measure contact area for outriggers?
A: Contact area is typically calculated by multiplying the length and width of each outrigger pad and summing the areas of all pads in contact with the ground.

Q3: Does the calculated GBP include the lifted load?
A: Yes, the total weight should include the crane's weight plus the maximum intended load to be lifted during operation.

Q4: What factors affect ground bearing capacity?
A: Soil type, moisture content, compaction, ground slope, and recent weather conditions all significantly affect ground bearing capacity.

Q5: When should I use crane mats or outrigger pads?
A: Use crane mats or larger outrigger pads when the calculated GBP exceeds the safe bearing capacity of the ground to distribute the load over a larger area.