A Case Study on the Use of Flexible Earth Retaining Structure In Instable Slopes

Recently new highway, motorway and railway projects take place in many developing countries within the aggressive infrastructure investment programme of governments. In rugged topography, engineers face the challenging problems of designing safe and cost effective cuts and fills for these projects especially under seismic loading and marginal stability conditions. Overall stability mechanism and safety of the cut generally controls the design decisions for the relevant section. In addition, because of the construction width limitations, in some mechanically stabilized earth wall projects sufficient width to accommodate the strip lengths of the retaining system cannot be provided. To eliminate all these problems, to minimize cut and backfill volumes and provide an innovative solution in such difficult terrains, soil nailing is implemented in the cut side together with the mechanically stabilized earth wall in the fill side together both are being flexible earth retaining structures. In addition, soil nails could be designed in such configuration and length that nails will also contribute to overall stability conditions of the cut slope. Furthermore, implementation of the system brings the advantage of reduction of both cut and fills volumes, therefore more cost effective and safer design. This paper presents application of this system in a recent case study, in Baku, Azerbaijan