Research On Bearing Capacity Of Suction Pile In Soft Clay

Suction piles are widely used in various offshore projects due to the advantages of convenient construction,low cost and reusability.However,due to the complex offshore environment,suction piles are often subjected to loads from wind,waves and currents,and are prone to instability and damage in practical engineering.On this basis,scholars have proposed improved "skirted suction piles" and "low skirted suction piles" to improve the bearing performance of suction piles.At present,the theoretical analysis and structural calculation of such piles are not systematic,and there are few studies on related aspects.Therefore,it is necessary to provide theoretical basis and technical reserves for the application of new foundations in practical engineering.Firstly,the limit equilibrium method was used to deduce the lateral and vertical ultimate bearing capacity of suction piles,and the determine method of soil resistance,frictional resistance and other related variables was given;the three-dimensional interaction between suction pile foundation structure and soil is established.The finite element numerical model takes into account the calculation domain,boundary conditions,contact properties and other factors,and the rationality of the established numerical model is verified.Secondly,a single load is applied to different types of suction pile foundations,and the failure state of the surrounding soil when the suction pile foundation reaches the limit state under the action of a single load is analyzed.performance impact.The study found that under the action of horizontal load and bending moment load,the soil around the pile mainly suffered shear failure,and under the action of vertical load,the soil at the end of the pile mainly suffered penetration failure;the skirt structure can improve the single bearing capacity of the suction pile.As the size of the skirt structure increases,the bearing capacity of the suction pile becomes larger;the height difference between the skirt top and the top of the main barrel has little effect on the horizontal and bending moment bearing capacity of the suction pile,but it has a greater vertical bearing capacity;The difference between the theoretical solution of the balance method and the finite element results is small,which proves that the method can be used to calculate the horizontal and vertical ultimate bearing capacity of the suction pile foundation.Finally,combined loads are applied to different types of suction pile foundations,the bearing performance of suction piles under combined loads is analyzed,and the normalized failure envelope is fitted.,the soil around the pile has shear failure and penetration failure at the same time;the setting of the skirt structure can obviously improve the combined bearing performance of the suction pile.