Abstract: During working process, suction bucket foundation is not only subjected to the action of vertical load induced by the weights of fan and equipment, but also imposed by lateral loads caused by wind, wave, and current. In the case of high-latitude waters, the suction bucket foundation structures may also suffered by long-term ice pressure. To this end, by using three-dimensional finite element model, this paper researches on the horizontal ultimate bearing capacity and instability mode of suction bucket foundation under the saturated drainage sand conditions, analyzes the suction bucket foundation failure mechanism when horizontal loading slowly, discusses the bucket foundation bearing performance under different length-diameter ratios; and the earth pressure distribution and the rotation axis position of bucket inner and outer are studied. Furthermore, based on the limit equilibrium method, a formula of ultimate horizontal bearing capacity for the suction bucket under saturated drainage sand conditions is deduced. The study results can provide the reference and basis for the design of suction bucket foundation in sand ground.

Key words: suction bucket foundation, saturated sand ground, horizontal ultimate bearing capacity, instability mode, limit equilibrium method