A Novel Approach for Assessing the Performance of Offshore Ground Improvement in Floating Storage and Regasification Unit (FSRU) Terminal Construction

A floating storage and regasification unit (FSRU) terminal has been planned to be constructed in Saros Bay (Türkiye). This study presents the ground improvement method using jet grouting to prevent the liquefaction of marine sediments in the project area. An approach for performance assessment of jet column construction is also discussed. The study site has a liquefiable ground level with a thickness changing between 2 m and 8 m. Jet grout columns with an 80 cm diameter were constructed under the sea level, which varied between 4 m and 18 m for ground improvement. The main issue is controlling the quality and performance of these jet columns. Therefore, a practical quality control procedure containing observational, mechanical, and geophysical methods for offshore grouting operations was proposed. The factor of safety values against liquefaction varied between 0.04 and 0.29 for natural conditions, while the minimum factor of safety after jet column constructions was obtained as 1.01. The results of the numerical analyses showed that the constructed terminal has sufficient performance against liquefaction. Consequently, the results of these methods have demonstrated that the jet grout applications performed by following this procedure are a suitable and effective improvement method for offshore soils.