Foundation Drillers & Caisson Workers

Drilled shafts, piers and caissons carry building loads deep into the ground. Crews drill open holes, lower rebar cages and place concrete. Some jobs need a worker to enter a shaft, which makes it a confined space with air, collapse and rescue risks.

• Foundation Crews
• Drillers
• Concrete

Hazards

• Open holes: people, equipment and tools can fall in. Cover or fence them at once. See Shafts & Pits.
• Bad air: low oxygen, carbon monoxide, hydrogen sulfide or methane in deep shafts. See Confined Spaces.
• Cave-in or sloughing of shaft walls without a casing or slurry.
• Falling objects dropped into the shaft.
• Moving rig parts, rebar cages and cranes. See Drill Rigs.
• Concrete placement hazards: pump hoses, tremie pipes, splash and silica.
• Utility lines and groundwater.

Entry rules

People should enter a drilled shaft only when it is necessary and the following are in place. Many projects avoid entry by using cameras, remote tools and slurry methods.

• A permit-required confined space program and entry permit. See Confined Space Rescue
• A casing or shoring that prevents collapse, designed by an engineer
• Atmospheric testing before and during entry, plus ventilation that continues while workers are inside
• A hoisting system (a crane-lowered personnel basket or other approved system) designed for people. See Hoisting Personnel
• An attendant at the top at all times, plus a rescue plan
• A way to communicate, and fall protection tied to the hoist
• Electrical equipment and lighting that are suitable for damp places

Daily practices

• Keep the area around the shaft clear. Use covers when drilling stops, even for breaks.
• Keep tools, spoil and equipment back from the edge so they cannot fall in.
• Use lifting gear rated for rebar cages and lift them with tag lines. Check the load path.
• During concrete placement, stay clear of hoses, whip and discharge points.
• Keep drilling slurry and spoil managed to avoid slips and spills.

Last updated: October 8, 2026