Extraction of suction anchors in sand with overpressure - Experimental study and numerical analysis

This paper demonstrates a series of 1g model tests and numerical modelling in order to investigate the pushout extraction process of suction anchors in sand. The suction anchor models used in this study have aspect ratios of 1 and 2, and the pumping rate and soil permeability are varied to reveal their influence on the extraction process. It is shown that changes in the pumping rate and soil permeability rarely alter the overpressure during the extraction process but can affect the displacement rate and final extracted length of the suction anchor. The ratio of the final extracted length over the total length of the suction anchor is also found to be different for suction anchors with different aspect ratios in the 1g model tests. Eventually, a calculation method for this pushout extraction process is proposed and validated to determine the peak overpressure with some basic parameters of the suction anchor and sands. The relationship between the pumping rate and the displacement rate of the suction anchor is also revealed in the calculation method.