Yasuo Sawamura

Centrifuge Model Test and FEM Analysis of Dynamic Interactive Behavior between Embankments and Installed Culverts in Multiarch Culvert Embankments

A multiarch culvert embankment is a new type of filling structure for which several precast arch culverts are installed continuously in the direction of the road extension. The key points in the design are to estimate the practical, optimal spacing between installed arch culverts and to clarify the interactive seismic behavior of the filling material and the culvert structure. In the current study, first, dynamic centrifuge model tests and a numerical analysis were carried out to clarify the basal earthquake behavior of the structure and verify the numerical approach. Then, the full-scale numerical analysis was performed to investigate the influence of spacing between multiarch culverts and the mechanical behavior under seismic conditions. From the results, it is confirmed that when the unit spacing is narrow, the whole rigidity of the ground and the arch culvert increases relatively. This is because the volume in the fill part, where the rigidity is small, decreases comparatively. Hence, the section force and the deformation are controlled.

Evaluation of dynamic behavior of culverts and embankments through centrifuge model tests and a numerical analysis

In the design of culverts in Japan, the effects of earthquakes are not usually considered in the design of conventional culverts. This is because culverts are thought to follow the deformation of the surrounding soil. Due not only to the increase in construction opportunities involving high embankments, but also to the development of new forms of culverts, such as precast arch culverts, which contain hinge structures, it is becoming more and more important to clarify the seismic performance of those culvert embankments. In this study, dynamic centrifuge modeling tests and a numerical analysis were carried out to clarify both the mechanical influence of the structural shape and the height condition of the embankment. From the results, it was found that the effect of the embankment condition on the increments in bending moments varies greatly depending on the structural shape of each culvert.