Model tests on static/seismic behavior of three-hinged multi-arch culvert constructed using different embankment processes

Abstract

A three-hinged multi-arch (THMA) culvert is a new type of underground structure that is gradually being adopted in practical engineering in Japan as an alternative to elevated bridges. However, there exist reports that THMA culverts were seriously damaged by earthquakes in the past, and research on the behavior of THMA culverts during the embankment process and exposure to post-construction earthquakes is insufficient. Therefore, to carefully investigate the static/seismic mechanical behavior of the THMA culvert, systematic 1 g shaking table model tests were carried out in the current study. THMA culverts were constructed using different embankment procedures in dry/saturated sand ground, and then subjected to seismic loading. The results showed that the different embankment procedures significantly affect the deformation mode of the multi-arch culvert on both dry and wet sand grounds, and the construction sequence involving simultaneous backfilling on both sides of the culvert can reduce the generated bending moments during seismic vibration. Furthermore, in all cases, the bending moments generated during the earthquake were significant on both sidewalls of the culvert in the range of 30°–60° from the ground, and the bending moments in the region near the hinges were smaller, which provided basic data for the optimized design of the culvert.