Abstract: The interaction between soil mass and bucket foundation under horizontal loads is analyzed. The equilibrium equations of forces and moments on a single and a quadruple bucket structure are formulated. The relation of lateral displacement of bucket top with horizontal loads is obtained based on a soil-spring model. The results of the bucket top displacements are compared with the three-dimensional finite element results. Good agreement is achieved. In addition, the safety and stability for the CB20B quadruple bucket foundation platform under different work situations are discussed.