Stability of highway embankments constructed on sloping ground against translational failure

Abstract

A translational failure of a highway embankment constructed on sloping ground may occur either in the mode of overall instability or in the mode of local instability. The stability analysis of the first mode is based on the assumption that the whole cross-section of the embankment will slide along the inclined base surface, whilst the second mode is based on the assumption of Rankine's active state of stress. In this paper the determination of the prevalent mode of failure --overall or local --is provided via a chart derived from force polygon analysis, with the dimensionless parameter, c¢/H, and the effective friction angle, '¢, as its axes. Furthermore, the determination of the most probable failure plane in the cross-section of the embankment is attempted and additionally the role of the cohesion in the stability is discussed. Finally, an estimation of the amplitude of failure at the road surface in the case of local instability is given. A confirmation of the aforementioned was achieved through case studies of highway embankments that have failed as a consequence of water infiltration and the development of high pore water pressures. A comparison between the local and the respective overall instability safety factor is given.

Semi-analytical model for the determination of vertical settlement of crest of road embankments founded on sloping ground

“…The last remain stable at the angle of rest of its material. In addition, the loss wedge to the upslope of the respective active is the one that determines the amplitude of failure at Pantelidis (2008a) the Rankine's active failure plane passes very close or through the intersection point between the crest and the outer slope of the embankment (Figure 1). Based on the above-mentioned failure pattern, a semi-analytical model for the determination of the vertical deformation of non-cohesive, homogeneous road embankments founded on sloping ground without benches has been developed.…”

“…Introduction Pantelidis (2008a) showed that a non-cohesive highway embankment founded on sloping ground is more prone to fail locally than its whole cross-section to slide downwards. The cross-section of an embankment of this kind can be divided into four areas, the downslope, active and loss wedge and the stable mass.…”