Design and installation of meteorological towers with tripod suction piles for offshore wind farms

Abstract

Typically, one or more meteorological towers are installed prior to the design of an off-shore wind farm to monitor the meteorological data at the planned site. Measurements include the atmospheric air pressures, wind velocities, and wind directions as well as the ocean current velocities and directions at various elevations. Two meteorological towers have been designed and installed during the summer of 2013 in Yellow Sea, west of Korea. The towers have a total height of 120 meters above the mean sea level. Both towers' foundations utilized a system consisted of tripod suction piles. The foundation system for the first tower consisted of three suction piles with each cylindrical steel pile having a diameter of 5 meters and a length of 13 meters. It is located approximately 47 km offshore with a water depth of 30 meters. Subsurface soil conditions included clay layers with sand layers in-between. The second tower foundation system also consisted of three suction piles with each cylindrical steel pile having a diameter of 7.2 meters and a length of 8 meters. It is located approximately 150 km south of the first tower and 40 km offshore with a water depth of 10 meters. Subsurface soil consisted of entirely sand. Meteorological measurements, including the predominant wind direction, will be used for the detailed design of wind mills whose capacities are expected to range from 3 MW to 7 MW. First wind mill is planned to be installed and operational in late 2015. Design, construction, and installation of these two tripod suction pile foundation systems are briefly described in this manuscript. Copyright © 2014 by the International Society of Offshore and Polar Engineers (ISOPE).