A novel bottom-supported offshore wind turbine bucket foundation platform employs a U-shaped mudmat as its foundation. This study designs three different foundation types for the platform： single mudmat

mudmat with four buckets

and skirted mudmat. A series of model tests and finite element simulations were conducted to investigate the effects of foundation type

loading height

and direction on the horizontal bearing behaviors of the foundations in sand. The results show that

under the same loading conditions

the horizontal bearing capacity increases by 66% for the mudmat with four buckets and 165% for the skirted mudmat compared to the single mudmat. The finite element results closely match the model tests

validating the reliability of the finite element analysis method. The single mudmat primarily exhibits translational motion

whereas the mudmat with four buckets and the skirted mudmat exhibit combined rotational and translational motion

and the skirted mudmat shows the highest rotational displacement

making its horizontal bearing capacity more sensitive to loading direction and height. Finite element analysis reveals that the failure modes for all three foundations involve plastic strain in the soil near the structures on the compressing side. During horizontal displacement loading

the mudmat and the compressed bucket provide approximately 80% of the resistance in the mudmat-buckets system

and the skirt contributes approximately 90% of the resistance in the mudmat-skirt system.