Seismic behavior of highway embankment reinforced with remedial countermeasures on saturated loose sandy layer

Abstract

A hybrid pile system is proposed to suppress excessive settlement and lateral spreading, which are regarded as main causes of highway embankment failure due to earthquakes. This system, combining two groups of vertical and inclined piles arranged on both sides of highway embankment slope, can be applied to existing highway embankments. In this research, a series of 1 g shaking table tests were performed together with modeling the performance of highway embankments incorporating three cases with different reinforcements subjected to two sinusoidal waves. Several aspects of acceleration time history, pile deformation, and embankment settlement under three configurations were revealed and discussed to confirm the effectiveness of the proposed countermeasures. The results indicate that (1) the hybrid pile system can still ensure sufficient functionality to maintain the highway embankment after two consecutive strong earthquakes; (2) this system can also enhance the integrity of loose sandy layer to reduce the settlement and lateral spreading of embankment; (3) the inclined piles effectively reduce pile head deformation by increasing the shear strength of the pile.