2007 Volume 24 Issue 1 Pages 23s-30s
In the seismic design codes for railway structures, a deformation capacity of RC piles is evaluated based on the experimental results, which have been obtained from alternate loading tests of RC columns under the atmospheric conditions. The actual behavior of piles, however, is likely to show a greater degree of ductility than these experimental results, because piles embedded in the ground are subject to confining pressure from the subgrade. In this study, we aimed to establish a rational evaluation method of seismic performance of pile foundations. A calculation method of ductility of RC piles is proposed, in which confining pressure by the subgrade reaction is converted into an equivalent passive confinement pressure from hoop reinforcements.
We have conducted alternate loading tests of RC columns supported by coil springs instead of the ground. We confirmed the applicability of the newly developed method by comparing these experimental results with numerical simulation results. In addition, we calculated the seismic response of railway structures with general shape and size using the proposed model, and confirmed the applicability of the proposed model to railway structures.
