Experimental Study on Static Pressure Sedimentation for a Thick-Walled Bucket Foundation in Sand

Abstract

As an emerging foundation structure for offshore wind turbines, bucket foundations with superior bearing capacities and efficient construction procedures have attracted significant attention in China. Thick-walled bucket foundations with concrete skirts can effectively reduce the cost and prevent the buckling problem of steel skirts during construction, transportation, and installation. However, great challenges are encountered during the sinking process, and the accurate calculation of sinking resistance is a critical process. Static-pressure tests of thin-walled and thick-walled models in sand were performed to measure the penetration resistance and soil pressure at the sidewalls and ends. The horizontal-soil-pressure coefficients of different models were calculated, and the end and skin-friction coefficients in the cone-penetration test method are recommended. The drag-reduction effects of the anti-drag ring and pressure-pull-out loading method were examined, and the drag-reduction effect was evident for the bucket foundation. The drag-reduction effect of the pressure-pull-out loading method is mainly reflected in the end zone.

Keywords

• thick-walled bucket foundation
• static-pressure sedimentation
• horizontal-soil-pressure coefficient
• drag-reduction strategy
• anti-drag ring