Piled foundations in many cases have a number of relatively small-diameter piles and they require a practical driving tolerance. Capping beams or pile caps are used to accommodate this tolerance and also to pick up varying widths of super-structure elements. If there are used large-diameter piles in some construction situations, pile caps or beams are unnecessary.
However, this can happen in so rare cases. The caps consist of concrete pads or beams constructed at the head of the piles. These elements are providing a connection between the pile and super-structure.