Rotary piling, often referred to as Rotary Bored Piling (RBP), is a widely used method in foundation construction for creating deep and robust foundations. It involves the use of specialized drilling equipment to excavate a bore (hole) in the ground, which is then typically filled with concrete and steel reinforcement to form a pile.
Understanding Rotary Bored Piling (RBP)
At its core, Rotary Bored Piling is a mechanical drilling process designed for removing various types of ground material, from soil to rock, to prepare for the installation of foundation piles. This method is highly effective for creating deep foundations, particularly in areas with challenging ground conditions or where precise depth control is critical.
The process leverages powerful machinery and specialized tools to efficiently excavate the earth.
How Rotary Piling Works
Rotary Bored Piling employs a systematic approach to create foundation bores:
- Equipment Utilization: The process uses a machine, called a piling rig, which is the primary piece of equipment. This rig is designed for heavy-duty drilling operations.
- Specialized Drilling Tools: The piling rig is equipped with specially designed drilling tools, including buckets and augers. These tools are critical for the excavation process.
- Buckets are typically used for looser soils or for collecting excavated material.
- Augers (large screw-like drills) are excellent for boring through denser soils, clays, and even rock formations.
- Material Removal: The primary function of these tools is to remove soil and rock from the bore, creating a void for the pile.
- Repetitive Boring: These tools are used to bore into the ground repeatedly. This iterative process allows for the gradual progression of the bore to the required depth.
- Spoil Removal: As the drilling progresses, spoil (excavated material) is continuously removed from the bore. This keeps the drilling path clear and allows for efficient advancement.
- Depth Achievement: The boring and spoil removal continue until the design depth is reached. This ensures the pile extends to the necessary bearing strata for structural support.
Key Components of Rotary Bored Piling
Understanding the essential elements involved in RBP helps in appreciating its effectiveness.
| Component | Description | Function in RBP |
|---|---|---|
| Piling Rig | A heavy-duty, powerful machine, often track-mounted for mobility. | Drives the drilling operation, provides torque for tools, and lifts excavated material. |
| Augers | Helical (screw-shaped) drilling tools. | Bore through various soil and rock types, bringing material to the surface for removal. |
| Buckets | Cylindrical tools with cutting edges at the bottom and a base for spoil. | Collect loose soil, muck, and excavated rock fragments, which are then lifted and emptied. |
| Casing | Steel tubes temporarily or permanently inserted into the bore (optional). | Stabilizes the borehole walls, preventing collapse in unstable ground conditions. |
Benefits and Applications
Rotary Bored Piling is a preferred method for various applications due to its controlled and precise nature. It's particularly effective for:
- Creating deep foundations for high-rise buildings and heavy structures.
- Working in areas with varying ground conditions, from soft clays to hard rock.
- Minimizing vibration, making it suitable for sites near existing sensitive structures.
- Achieving high load-bearing capacities due to the large diameter and depth achievable.
