What ground surface would be least adequate for machine set-up?

What ground surface would be least adequate for machine set-up?

• A. Sand
• B. Gravel
• C. Rock
• D. Mud

Answer: (A)

Ground stability and bearing capacity are what determine a safe crane setup. For a stable setup, you need a firm, level surface that can evenly distribute the load from the outriggers. Sand is the least adequate because its grains are loose and shift easily under weight, causing deformation and sinking of the outriggers which leads to an unstable, wobbly base. In contrast, solid rock provides a hard, supportive surface, and compacted gravel can distribute load more reliably. Mud is also problematic because it can be soft and compressible, especially when wet, but the most unreliable among these options for consistent support is sand.

Ground stability and bearing capacity are what determine a safe crane setup. For a stable setup, you need a firm, level surface that can evenly distribute the load from the outriggers. Sand is the least adequate because its grains are loose and shift easily under weight, causing deformation and sinking of the outriggers which leads to an unstable, wobbly base. In contrast, solid rock provides a hard, supportive surface, and compacted gravel can distribute load more reliably. Mud is also problematic because it can be soft and compressible, especially when wet, but the most unreliable among these options for consistent support is sand.