This type of pile installation is used to replace soil removed by drilling rather than occupying the space of displaced soil as in driven piles and thus, it mostly relies on end-bearing capacity of the earth layer at the drilled depth.Bored piles provide the largest pile dimensions and thus the highest load bearing capacities.
One method of installation is to drill a shaft using a continuous auger with a hollow stem at its center which is later used to grout the drilled shaft. This method is known as Continuous Flight Auger.
Another technique is to drill the shaft, insert the reinforcement steel cage (if required) and then pour concrete under pressure to fill the entire shaft space. The shaft is drilled using an auger in dry land conditions and a drilling bucket in wet land conditions.
When shaft wall support is required, the drilling process takes place inside a steel casing or with the aid of drilling slurry such as Bentonite.
