Caisson pipes, also called drilled shaft casings, bored piles, or drilled piers, are large cylindrical watertight structures used in the construction of foundations. These colossal pipes can range in size from two to seventeen feet in diameter and up to two inches thick.
While useful for a variety of heavy-duty construction projects, caisson pipes are most commonly utilized where water is an issue, such as bridges, oil platforms, or in damp soil. Constructing a watertight space where concrete can properly dry is vital in these areas.
Caisson pipes are commonly made from:
- Rolled Pipe
- Welded Pipe
- Spiral Weld Pipe
How Caisson Pipes Are Utilized
A hole is drilled to the desired depth and diameter. The caisson pipe is either used as the drill itself or is slotted into the shaft afterward. Either method will ultimately create a watertight seal.
Soil and debris are removed, and air pressure can be deployed to push any water out of the caisson pipe and maintain a dry environment. A foundation is laid to complete the seal. This area is then used as a safe chamber for further construction or as a place where concrete can effectively be poured to create a foundation piling.
The caisson pipe remains as a protective and supportive casing around the new concrete pier, which helps strengthen the structure against axial, lateral, and overturning forces.
Common Caisson Construction Projects
While most common in situations where water is an issue, the value of caisson pipes can be seen in any deep-foundation project. The large concrete piers they produce are valuable for holding large loads while also providing strong lateral resistance.
Caisson pipes are beneficial for reducing the number of piles required for a foundation, which lessens the overall workload and material cost of the project.