Experimental Study On The Influence Of Negative Pressure And Loading Angle On Suction Foundation Bearing Capacity

Suction bucket foundation is a new type of marine foundation,which has been widely used in offshore platforms,offshore wind power and other marine resources development in recent years.The suction bucket foundation will be subjected to the pulling load from the wind and waves,and the offshore environment is complex and variable.The wind and wave load has periodicity,which is fast and slow,and the load frequency acting on the suction bucket foundation will be different.The upper part of suction bucket foundation is connected with wind turbine,and under the action of the wind turbine,suction bucket foundation may be inclined under the action of wind turbine,Suction bucket foundation may be subjected to the tilting force.Negative pore water pressure will be generated in the bucket during the uplift process of suction bucket foundation,which will improve the pulling capacity of suction bucket foundation.Therefore,it is of great significance to study the uplift capacity of the suction bucket foundation under different loading rates,different loading angles,the change law of negative pore water pressure and the influence of increasing negative pore water pressure on suction bucket foundation uplift capacity.This article is based on the National Natural Science Foundation of China(Nos.51574139),the uplift capacity of suction bucket foundation under different loading rates and different loading angles is investigated in sand and clay by self-made test device.Loading displacement rates of 0.4mm/s and 0.1mm/s were used to carry out uplift test with opening and closing in sand and clay respectively.The variation law of negative pore water pressure in suction bucket foundation bucket in sandy soil and clay soil was investigated respectively.The uplift test under different negative pressures was carried out in clay.The influence of negative pore water pressure on the uplift capacity of suction bucket foundation was investigated.Through the experimental research,the following conclusions are obtained:(1)The uplift capacity of suction bucket foundation increases obviously with the increase of loading displacement rate.However when the loading displacement rate increases to a certain extent,the uplift capacity of suction bucket foundation tends to be stable and no longer increases.(2)The uplift capacity of suction bucket foundation under vertical uplift load is smaller than that under tilting load.With the increase of loading angle,the uplift capacity of suction bucket foundation decrease.(3)With the increase of the negative pore water pressure,the uplift capacity of suction bucket foundation increases.