Cased driven piling is a technique which is useful when working in areas offering only limited headroom or access. It involves a length of steel casing being lowered into a small hole which has already been drilled into the ground. A concrete plug is then created in the metal casing and a weight is dropped onto this concrete plug repeatedly, acting like a hammer which drives the plug and the casing deeper into the ground.
As the casing goes deeper into the ground, another section can be welded onto it, thus extending the length of the casing and the depth of the bore. Over time, the weight will drive the casing to the required depth. The depth needed can be calculated accurately on site and achieved via the use of a given weight dropped from a specific range of heights.
When the correct depth of bore hole has been reached, a reinforced cage is lowered into it, and then the hole is filled with concrete. The advantages of this method, besides the fact that it can be used in difficult to access sites, include a lack of waste material and the fact that it is useful when the conditions of the soil are unknown or uncertain. The mechanics of the technique mean that, once a set has been reached, it is known the pile will bear the intended weight.
We have rigs capable of creating cased driven piles of all sizes, whether large or small, and all of our rigs have their own portable power packs.