2019 年 7 巻 1 号 p. 112-123
More reasonable seismic design can be achieved by considering input loss effects of soil-foundation interaction. However, in the present seismic design, there is no practical evaluation method available for a static analysis of input losses for foundations widely used in a railway field. In order to achieve optimal structural design, this paper illustrates a practical method for evaluating input loss effects for static analysis. First, sensitivity analysis was conducted for varying conditions of both soil and piles, and input loss effects caused by pile foundations were investigated. Then, a practical method for calculating effective input losses by the seismic deformation method was proposed, along with a brief method for lowering the nonlinear response spectra considering input losses based on the random vibration theory. Furthermore, applicability of these methods was verified by comparing the dynamic analysis results and evaluated results.