Numerical Analysis Of Soil Plug Inside Suction Anchor During Suction Penetration

Suction anchor is a new style of offshore platform foundation. The soil plug phenomenon is the key problem during the process of suction penetration of suction anchor in construction. By numerical analysis of seepage field of suction anchor and discrete element method of round rigid element simulating soil around the anchor, the relevant program (SPSA) is written for computing soil height during suction penetration of suction anchor. During the construction of suction anchor by suction penetration, the soil plane inside the anchor would be upwards forced by the difference of suction inside and outside of the anchor and seepage force inside the soil. Therefore, soil plug will touch the top of the anchor and prevent the penetrating of suction anchor in advance. The height of soil plug is influenced by the sorts of soil besides the suction magnitude, the velocity of penetration, original close conditions, friction magnitude of edge of suction anchor and the dimension of suction anchor, etc.The program (SPSA) mentioned above simulates the soil plug height in the 3 different soil of silty clay, silty and sand during the suction penetration. Through comparing the results of program with the results of software of Algor and test records, it is proved that the results are reasonable and the discrete element method is available for simulating soil in computing height of the soil plug. By the analysis of the results, the conclusion is that the suction force is the main reason contributed for the soil plug as well as the seepage force. The sort of soil and its physical parameters, to some extent, is some reason, too. The research of soil plug inside suction anchor is a meaningful reference for the suction control during the process of suction penetration and the suction anchor's design and construction.