“What’s a caisson?”

Basically, it’s a very deep hole  We fill with concrete. We use caissons to support man-made structures. Since they need to hold a lot of weight, we often reinforce caissons with rebar cages. Caissons are commonly used when constructing bridge piers. For an example of a caisson used on a bridge see Hunter’s Station Bridge.

We begin by drilling an open shaft all the way down to bedrock. If the open shaft might collapse, we place temporary steel casings in the hole to keep it open. Once we reach bedrock, we drill rock sockets to a depth determined by an engineer. Next, we place a rebar cage into the shaft and pour concrete the required elevation. Finally, we remove all temporary casings from the shaft. The size of a caisson could range from 18″ to 12′ in diameter, and the depths all very depending on soil conditions. Besides bridge piers and dams, caissons are also used in some building foundations.

If you need a caisson constructed for your project, contact us for an estimate.

Caisson diagram
Drilling a drilled shaft