Experimental Study On The Influence Of Flap On The Buried Depth Loss And Bearing Capacity Of Suction Penetration Plate Anchor By Transparent Soil

Suction Embedded Plate Anchor(SEPLA)is a new type of anchor foundation of offshore floating structure,which will cause the loss of buried depth during installation and uplift,thus reducing the bearing capacity.In order to reduce the buried depth loss,it is proposed abroad to connect the anchor flap at one end of SEPLA anchor plate,but it is not clear whether the anchor flap can reduce the buried depth loss of SEPLA and improve its bearing capacity.In this paper,a self-made transparent soil test device for SEPLA rotary uplift is designed to study the influence of three types of anchor flaps and uplift angles on the buried depth loss and bearing capacity of SEPLA.The morphological changes of SEPLA with different types of anchor flaps during rotary uplift and the flow of surrounding soil are observed,and the action mechanism of anchor wings during rotary uplift is analyzed.The following conclusions are obtained:(1)In the process of rotating and pulling up SEPLA,the anchor flap can effectively reduce the buried depth loss of SEPLA,speed up the rotating speed of SEPLA,and SEPLA can reach the maximum bearing state faster and improve the bearing capacity.The external anchor flap has no obvious effect on reducing the buried depth loss of SEPLA and improving the bearing capacity.(2)According to the change of the angle of the anchor flap,the SEPLA of the inner rotating anchor flap is divided into four stages: in the first stage,the angle of the anchor flap of the inner rotating anchor flap SEPLA increases rapidly to 20°,and SEPLA only produces a slight buried depth loss;In the second stage,the angle of anchor flap is kept constant at 20°,and SEPLA mainly rotates,resulting in a certain buried depth loss.In the third stage,the angle of anchor flap decreases rapidly from 20°to 0°,and SEPLA causes certain buried depth loss.In the fourth stage,the angle of anchor flap is kept at 0°.In the process of SEPLA rotary lifting of the internal rotary anchor flap,at the beginning,the anchor flap does not rotate,the eccentricity ratio of the anchor eye increases,the SEPLA rotary speed is fast,and the buried depth loss is reduced.(3)In the initial stage of SEPLA’s rotary uplift,the soil flows elliptically around the anchor plate of SEPLA’s internal rotary anchor flap;Rotating the outer anchor flap and the non-anchor flap SEPLA,the soil flows elliptically around the SEPLA.The last,the soil flows around the whole oval shape of the internal rotating anchor flap SEPLA;Rotating the outer anchor flap and the non-anchor flap SEPLA,the soil flows elliptically around the SEPLA;At last,the soil forms an asymmetric flow around both ends of SEPLA,reaching the bearing state and the shape is unchanged.(4)In the process of SEPLA rotary pull-up,the angle of the anchor flap is approximately 0° at the beginning for a long time,and there is no relative rotation between the anchor flap and the anchor plate.The external rotary anchor flap is not conducive to reducing the buried depth loss and improving the bearing capacity.(5)The larger the lifting angle of the load,the greater the buried depth loss of the three types of SEPLA when they reach the bearing state.