Impacted piles, flushed and vibrated part 2

Prefabricated piles are usually used for foundations in open water, when the protruding part of the pile is to remain submerged in the water. Under such conditions, the execution of driven piles presents some difficulties. Prefabricated piles are made with a square cross-section, rectangular, polygonal, round or I-shaped. Moreover, they can be solid or hollow of uniform length or of sections. The most common types of reinforced concrete piles are shown in the figure.

tmpb330-1Types of prefabricated reinforced concrete piles: a) longitudinal sections, b) cross sections.

The piles are usually made of a full square cross-section with slightly cut corners. Rectangular or I-section piles are generally used in these conditions, when it is necessary to transfer bending moments. They are driven into the ground like this, so that the plane of the bending moments is parallel to the longer side of the section.

The piles are rinsed in by means of a pressurized water stream, provided by the appropriate pipe (scrubber). The water loosens the ground around the pile, which sinks into the ground under the influence of its weight and only light beating. Washing the piles with water current loosens the soil around the piles and reduces their load-bearing capacity compared to driven piles.

The pile is vibrated by vibrators placed on top of the pile, which cause vibrations of the pile and the surrounding soil. Due to the vibrations, the resistance of the ground is significantly reduced and the pile sinks under its own weight.