INTERNAL FORCE EVALUATION OF A SUBMERGED FLOATING PIPELINE UNDER IRREGULAR WAVES

Abstract

Generally, submarine pipelines are laid on the seabed to transport water, oil, natural gas, and electricity to the land using submarine cables. However, they are not suitable for all seafloor conditions. There are environmental concerns such as deep seas, irregular seabed features, soft soils, transported materials and so on. To overcome these challenges, a submerged floating pipeline (SFP) concept was proposed. To stay in the middle of the water, the SFP has buoyant modules as floating devices. It is unrestricted under environments such as uneven seabeds, and deep waters, and is suspended to avoid interrupting passing vessels. This SFP model was applied in some parts of the water supply project from southern Turkey to Northern Cyprus in 2014. It was found that SFPs have advantages of application in various underwater environmental conditions. In this study, the internal forces of SFPs were evaluated under the irregular wave condition. The main parameters were set as the buoyancy to weight ratio, anchoring method of the tendon, suspended depth of the pipes, and incident angles of the wave. Consequently, the SFP was subjected to not only bending forces but also torsional forces. The sectional characteristics of the pipe were analyzed based on the results to conclude on the optimum design.