The Study On Towing By Air Floating Of Bucket Foundation Platform

The bucket foundation platform replaced the tradition pile foundation of jacket platform with the bucket foundation. It is named as"the new century'dawn of jacket foundation engineering".it has the merit of saving investment, reusing, and so on. In addition, the bucket foundation platform has the possibility of air floating. Therefore, if the bucket foundation structure air floating technology can be applied in projects, the economic efficiency will be remarkable extremely.The whole paper can be devided into two parts. The first part introduces the influence mechanism compressed air half-closed in bucket to the float state of structure is analyzed, and all analysis method to calculate the float state of structure with air-filled buckets is established. The formulas calculating the flotage of air-filled bucket and the force equilibrium equations of structure derived according to the assumption that the compression relationship of the air half-closed in bucket is linear.The following analysis methods about the property parameters of air floated structure are obtained. The stability of the air floating platform is judged by the parameter of meta-centric height.The formulas of calculating the meta-centric height are presented. Simplifying the air floating structure as a single freedom rigid body and spring system.the inherent period of heaving and some kinetic properties are presented. The air floating decrease factor represents the difference of restoring forces between the conventional floating structures and the air floating ones, and it has large influence on the floating state, stability and kinetic properties of the air floating structures.The second part of this paper introduces the needs to be pay attention question in the preparation and the survey work bofore the bucket foundation platform is towed by air floating. Preparation and survey of towing operation for offshore mobile platform are summarized and discussed.These items include the stability of towing, selection of weather condition, the estimation of towing force and the equipping of towing facilities. In the towing schemes analysis, the relation of towage resistance and towage velocity, immerged depth of pontoons and the position of towage cable is studied. Finally the bucket foundation platform towing by air floating experiment is introduced, through the experiment and the theoretical analysis, the theoretical results are in good agreement with the data observed from the prototype test. Analysis...