In this paper, structural analysis and causual analysis of superstructure horizontal displacement by retaining wall displacement is realized, as a result, it is considered that retaining wall displacement by soft soil and lateral flow pressure occurred in the soft soil affect superstructure horizontal displacement. Although resistance force is slightly larger than the action force when reviewing superstructure safety, it is considered that repair and reinforce are necessary when considering safety factor with respect to the difficulty of estimating accurate load, and the uncertainty of soil condition.