BORED PILE CONSTRUCTION METHOD
This method defines the selection of machines, equipment, materials, preparation, application, and quality-control procedures required for bored pile construction. The works are carried out in accordance with TS 3168 / EN 1536 – Special Geotechnical Applications – Bored Piles (Cast-in-situ Reinforced Concrete Piles).
1. Site Preparation
The construction and access areas must be kept level, dry, and suitable for heavy machinery such as drilling rigs, crawler cranes, concrete trucks, and pumps. Proper drainage must be provided, and groundwater or drilling slurry must be continuously removed.
2. Soil Information
All methods and execution details follow the soil investigation reports.
3. Environmental Conditions
Underground or surface obstacles (concrete, steel, utilities) must be identified and removed by the employer after official notifications.
4. Pile Layout & Tolerances
Pile locations are staked by professional surveyors. Verticality and inclination tolerances must comply with project limits. Adjacent piles must not be drilled too soon to avoid soil disturbance.
5. Drilling Works
Drilling is performed using high-torque hydraulic rigs with telescopic kelly systems. Clay buckets, rock augers, or drilling tools are selected according to ground conditions. Casing pipes are used where groundwater, soft soils, or collapse risks exist. Bentonite slurry may be used when required.
6. Reinforcement Cage Installation
Reinforcement cages are assembled near the pile area, lifted carefully, kept clean, and lowered into the borehole with proper cover blocks.
7. Concreting
Concrete is supplied from certified plants. Concreting must begin immediately after reinforcement placement using the tremie method. The tremie pipe must remain at least 1 m embedded in fresh concrete to prevent segregation. Concreting continues until clean concrete appears at the surface.
8. Concrete Samples
Cube samples are taken according to EN 206 and EN 1536 standards.
9. Reporting
Daily pile records must include: pile location, depth, casing depth, drilling times, concrete times and volume, reinforcement details, and soil layers encountered.
10. Quality Control
All works and materials are inspected according to project quality control guidelines and material acceptance standards.