Evaluation of Hybrid Pile Supported System for Protecting Road Embankment Under Seismic Loading

A 1 g shaking table testing program was conducted to assess the dynamic performance of an innovative cost-effective countermeasure technique for new and existing road embankment on a liquefiable foundation subjected to cyclic sinusoidal loading. The model was shaken with a scaled earthquake motion having peak base acceleration of 0.2 g and 0.3 g in the first and second events which simulate the foreshock and mainshock of the 2016 Kumamoto earthquakes. In a series of four different shaking table model tests, the dynamic response of the embankment was investigated first without, and then considering three countermeasure techniques: pile supported embankment, connected piles-geogrid system supported embankment, and hybrid pile system supported embankment. The mechanism of remediation and performance of each proposed countermeasure techniques are discussed based on dynamic response of embankment. The effectiveness of each technique on preventing the development of pore water pressure and limiting the deformation of embankment was studied in this research. The hybrid pile supported system was found to be effective in maintaining the overall stability of embankment during earthquake loadings.