FILLING MANAGEMENT METHOD OF SUBSEA GROUT CONNECTION FOR JACKET TYPE OFFSHORE WIND FOUNDATION

Abstract

 Aiming to develop a filling control method for underwater grout joints of jacketed offshore wind turbine foundations using a two-hole RI meter, we conducted a two-stage laboratory experiment to verify the applicability of the two-hole RI meter and the measurement accuracy of this method. As a result, it was confirmed that the distance between a pair of guide pipes into which the gamma-ray source and detector are inserted should be set at 300 mm to 400 mm, and the measurement time should be at least 3 minutes. It was also confirmed that the RI meter should be inserted vertically downward at least 150 mm to the grout joint in water. The measurement accuracy was confirmed to be ±0.017 t/m³, taking into account statistical noise due to catastrophic oscillation of the gamma-ray source and measurement error due to horizontal displacement of the RI meter. By upgrading this technique, it’s shown that this technique can be used to quantitatively control the filling of underwater grouting materials.