Research On The Influence Scope Of Bucket Foundation Installation In Silty Clay

As a non-pollution clean energy,wind energy has gradually attracted people's attention.Due to the limited land-based wind energy resources,in recent years many countries have shifted the focus of wind power development to the sea.The wide and shallow bucket foundation is a new type of offshore wind power foundation,which enjoys quick installation,lower cost and recyclability.The wide and shallow bucket foundation is designed to withstand the large bending moments transmitted from the 100-meter-tall tower to the base through an oversized designed diameter(?30m).The one-step installation is a prominent advantage of the wide and shallow bucket foundation.During the installation,the bucket wall extrudes the surrounding soil,resulting in the change of the pore water pressure,which causes the reduction of effective stress in the soil and the change of soil strength.Therefore,it is great significance to accurately evaluate the disturbance range and disturbance degree of the bucket foundation installation to the surrounding soil body to ensure the overall stability of the structure during the construction period.In this paper,the silty clay widely distributing along the coast of China is taken as the research object,and the model test of the bucket foundation installation is carried out.The disturbance law of the bucket foundation installation process to the surrounding soil is revealed.The main content and conclusion are as follows:(1)The self-weight penetration and suction installation experiments of bucket foundation are carried out.The self-weight penetration and suction installation process of bucket foundation are simulated.The changes of pore water pressure,earth pressure and soil strength before and after installation are monitored.(2)Based on the theory of cavity expansion,the formula for calculating the maximum radial influence scope of bucket foundation installation is derived.The results show that the radial influence scope of the self-weight penetration on the surrounding soil is 2.2 times the radius;the radial influence scope of the suction installation on the surrounding soil is 1.6 times the radius.(3)The finite element method is used to simulate the self-weight penetration and suction installation of bucket foundation.The results show that the influence area of excess pore water pressure increases with the increase of the depth of bucket foundation during self-weight penetration.When bucket foundation is under suction installation,excess pore water pressure mainly distributes in the bucket,and only a small part distributes near the end of the bucket.Externally,the influence scope of suction pressure on the surrounding soil is about 1.5 radius.