When the ground is uneven, it is very necessary to use additional pads or adjust the structure of the outriggers to ensure that the crane remains level, stable and evenly stressed.
Why is it necessary to use additional pads for uneven ground?
Risk Consequences
Outriggers are suspended in the air and cannot be effectively stressed, which makes it easy to lose balance or overturn during lifting
Outriggers are unevenly stressed. One leg is overloaded, resulting in cracks in the pad, bending of the outriggers and even collapse of the ground
Crane is not level. The swing of the hoisting arm is limited, the shaking of the heavy objects increases, and the operation is extremely unsafe
How to deal with uneven ground? (Recommended practice)
- Use additional pads for leveling
Use wood blocks, rubber pads, thick steel plates, composite plastic pads and other materials to add pads under the outrigger pads and adjust them to the same level for each leg;
A common practice is to use a large outrigger pad + several layers of small leveling blocks; - Ground pretreatment
If construction is possible, it is recommended to use sand, concrete or steel plates to simply level the soft ground or potholes in advance;
If necessary, lay a ground protection mat to form a temporary leveling platform. - Use an automatic leveling system (limited to high-end equipment)
Some modern cranes have electronic level detection + hydraulic automatic leveling functions, but they still require the cooperation of a foundation pad.
Recommended configuration example
Component Purpose
Main leg pad Large size for pressure bearing, placed at the bottom layer
Leveling pads (small pads) 1 to 3 layers stacked on the main pad to adjust the local height
Block box/leg tool box Carry spare leveling blocks for quick on-site adjustment
Practical suggestions
When the ground height difference is large: a combination of pads of different thicknesses may be used under each leg;
The pads must be made of strong, non-slip, and crack-resistant materials, and cannot be made of fragile wood or bricks;
The leg must be fully in contact with the center of the pad, and cannot be suspended or skewed;
All legs must land at the same time and the force must be balanced, and one side cannot land first.