Method for arranging a foundation in an underwater bottom from a vessel

Abstract

Described is a method for arranging a foundation in an underwater bottom from a vessel. The underwater bottom comprises a top layer and a rock layer located thereunder. The method comprises of arranging a first foundation pile with internal cavity through the top layer and onto the rock layer, wherein the first foundation pile finds support on the rock layer. A shaft is then drilled through the first foundation pile and into the rock layer. The shaft has a transverse dimension smaller than an internal transverse dimension of the first foundation pile. A second foundation pile is then arranged in the shaft down to a depth in the rock layer, wherein an exterior surface of the second foundation pile extends into the shaft and also overlaps with an exterior surface of the first foundation pile over an overlap length. Finally, the exterior surface of the second foundation pile is connected to the shaft wall and to the exterior surface of the first foundation pile over substantially the overlap length.