Cut stabilization on the highway E-763 made in rock mass with unfavorably oriented discontinuities

Abstract

During the construction of the highway "Miloš Veliki" E-763 through Serbia, in addition to many challenges, it was necessary to stabilize the cut at the section km 81+250 to km 81+650. The cut was supposed to be constructed in the soft layered rocks of the Ljiški flysch complex, made of sandstone, marl stone and shales. The orientation of the rupture assembly of the rock mass as well as the spatial position of the slope led to a series of instabilities on the left side of the cut, while at the same time they had a positive effect on the stability of the right side. All occurrences of instability were accompanied by a dip direction of bedding, which on the left side of the cut had a dominant negative impact on the strength of the rock mass. For the purposes of geotechnical modeling and determination of remedial measures, the parameters of the rock mass were obtained using classifications of the rock mass, while the parameters of rock mass discontinuities and sliding surfaces were obtained from back analyzes of slipped rock blocks or slipped debris material. By using passive anchors, subhorizontal drains, shotcrete, wire netting, reinforced soil and facing RC walls, this cut was successfully stabilised.