Evaluating the cumulative settlement of railway embankments constructed with tunnel spoil

• Cumulative settlement of railway embankments made of tunnel spoil evaluated. • Cumulative settlement of tunnel spoil similar to that of compactable materials. • Validity of analytical method based on cumulative damage theory confirmed. • Settlement of embankments made of tunnel spoil satisfies the slab-track support standard. In railway design, it is important not to allow large settlements on the embankment supporting slab tracks because it is difficult to repair track irregularities of slab tracks. Therefore, although the “ Design Standards for Railway Structures (Earth Structures) ” in Japan indicates that high-quality tunnel spoil can be applied as railway embankment material, a separate study is required about the cumulative settlement characteristics under cyclic train loading when using materials with large grain sizes. However, few studies have been conducted on the cumulative settlement characteristics when tunnel spoil is applied to embankments for the slab tracks of the Shinkansen. In this study, the cumulative settlement on an embankment built with tunnel spoil under cyclic loading was evaluated experimentally, using a vibrator machine, and through an analytical method. First, the authors constructed a test embankment using tunnel spoil and conducted cyclic loading tests employing a large vibratory machine. Next, the authors verified the validity of the analysis method, which combines the cumulative damage theory approach and two-dimensional analysis using the finite element method, by comparing the cyclic loading test results with the simulation results of the cyclic loading tests. Subsequently, using this analysis method, the amount of plastic settlement of the embankment under actual Shinkansen slab tracks was calculated and confirmed to be within the applicable range.