Verification of Seismic Deformation of Road Embankment Laying on the Coast Using Numerical Analysis

Following the 2011 Off-Pacific Coast of Tohoku Earthquake, embankments have again attracted much attention as a tsunami restraining measure. Because of alluvial deposit widely distributed along the coast, liquefaction of the ground often obstructed the traffic function. In this paper, the characteristics of the sedimentary layer of the coast are sorted out from the viewpoints of landform division and grain size analysis results for a local coast in Kochi Prefecture. Furthermore, effective stress analysis is conducted at various liquefaction ground condition represented in the coastal area. Using the results of this analysis, the relationship between the characteristics of the ground and embankment deformation is established. Finally, a simple evaluation method for road embankment settlement is suggested using the results of the effective stress dynamic analysis which is often conducted for the design of road embankments with a large-scale earthquake in mind.