Blocking under rigging pads is determined by which factors?

Blocking under rigging pads is determined by which factors?

• A. Ground bearing capacity and ground bearing pressure generated by the crane
• B. Load weight
• C. Temperature
• D. Wind speed

Answer: (A)

Blocking under rigging pads is driven by the need to keep the ground pressure beneath the pads within what the soil can safely bear. The key ideas are the soil’s bearing capacity and the bearing pressure the crane’s outriggers create. You look at how the total load supported by the crane is distributed across the outriggers, then divide that load by the contact area of each pad to get the bearing pressure. If the resulting pressure exceeds the soil’s allowable bearing capacity, you need larger pads or a wider outrigger spread (or more pads) to reduce the pressure. Temperature and wind speed don’t set the pad size directly, since they don’t change the static bearing pressure the ground must support; they affect stability in other ways, but the blocking choice rests on soil bearing capacity and the pressure from the crane’s load.

Blocking under rigging pads is driven by the need to keep the ground pressure beneath the pads within what the soil can safely bear. The key ideas are the soil’s bearing capacity and the bearing pressure the crane’s outriggers create. You look at how the total load supported by the crane is distributed across the outriggers, then divide that load by the contact area of each pad to get the bearing pressure. If the resulting pressure exceeds the soil’s allowable bearing capacity, you need larger pads or a wider outrigger spread (or more pads) to reduce the pressure. Temperature and wind speed don’t set the pad size directly, since they don’t change the static bearing pressure the ground must support; they affect stability in other ways, but the blocking choice rests on soil bearing capacity and the pressure from the crane’s load.