Pier drilling is crucial to many structures, as it provides a strong and sturdy foundation. A pier is typically a drilled boring and is called either a pier shaft or caisson shaft. After drilled, the shafts are filled with concrete to provide a deep foundation beneath an above ground structure. These can be reinforced with steel or unreinforced depending on the loading conditions of the structure. Piers usually range in diameter from 18 inches up to 120 inches and depths as needed.
The boring is typically drilled with a dirt auger or a core barrel when hard layers of rock or obstructions are encountered. The pier is either drilled to a suitable subsurface geologic zone or to a depth as required to develop sufficient friction along the walls of the boring which will support the weight of the structure.
Belling is the process in which the bottom of the shaft is beveled out or enlarged. The bell is created after the straight shaft portion of the pier has been drilled to the necessary depth. The belling tool is lowered to the bottom of the pier and the wings of the tool open up as the rig turns the tool; this process forms the bell. Belling results in a substantial increase in bearing capacity while minimizing the quantity of concrete required for the pier. Performing this type of pier is susceptible to caving.
Piers provide an economical foundation system for support of a wide range of structures. Talon/LPE has a wide variety of augers, core barrels and belling tools. Contact Talon/LPE for your next pier job!