PIL/Types/TBT-PIL-006

Bored Pile Installation (Rotary)

Piling & Foundations › Types › Bored Pile Installation (Rotary)

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Rotary bored piling uses a drilling rig to auger or core into the ground and form a cast-in-situ pile.
The process generates large volumes of excavated spoil that must be managed safely on site.
Temporary steel casings are often used to support the borehole in unstable ground conditions.
Bentonite or polymer support fluids are pumped into the bore to prevent collapse in granular soils.
The reinforcement cage must be lifted and lowered into the bore using a planned crane lift.
Concrete is placed by tremie pipe from the base upwards, displacing the support fluid as it rises.
The piling rig is heavy and requires a stable platform designed to carry the full operating weight.
Noise and vibration from rotary piling are lower than driven methods but still require assessment.
CDM 2015 and LOLER 1998 apply to all lifting, plant operations, and concrete placement activities.
Underground services must be confirmed clear before any bore position is drilled.

Collapse risk	Unsupported boreholes can collapse without warning, trapping workers or equipment.
Heavy lifting	Reinforcement cages and casings require lift plans — dropped loads cause fatal injuries.
Ground contamination	Support fluids and spoil must be managed to prevent environmental pollution.
Plant stability	Rig overturning on inadequate platforms causes catastrophic incidents.

Don't

Verify the piling platform is designed and approved for the rig's operating weight.
Confirm underground services are located and clear before drilling each bore.
Use a lift plan for placing and extracting temporary casings and reinforcement cages.
Monitor borehole stability continuously during drilling and concreting operations.
Manage support fluid levels to prevent bore collapse in granular ground.
Maintain an exclusion zone around the rig during all drilling operations.
Dispose of drilling spoil and support fluids in accordance with environmental permits.
Brief the team on the day's pile sequence, lifting plan, and emergency procedures.
Inspect all lifting accessories before each cage and casing lift.
Record pile installation data including depth, concrete volume, and cage details.

DON'T position the rig on ground that has not been assessed for bearing capacity.
DON'T drill without confirming underground services are clear at each bore location.
DON'T allow anyone to lean over or look into an open borehole.
DON'T lift reinforcement cages without a documented lift plan and rated slings.
DON'T allow support fluid levels to drop below the minimum required to prevent collapse.
DON'T enter the exclusion zone while the rig auger or kelly bar is rotating.
DON'T discharge support fluids or contaminated spoil into watercourses or drains.
DON'T continue drilling if the rig shows signs of instability or settlement.
DON'T stand beneath a suspended reinforcement cage during lowering into the bore.
DON'T skip pre-shift inspections on the rig, crane, and lifting equipment.

See also: Piling Safety Awareness | Piling Platform Requirements

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