Vystužené horninové konštrukcie a vystužovanie zemných svahov
ŽILINA - ŽILINA - Slovensko
NÁRODNÁ DIAĽNIČNÁ SPOLOČNOSŤ
D1 HRIČOVSKÉ PODHRAIDE – LIETAVSKÁ LÚČKA, SO 206-00
The retaining wall is needed to retain bridge abutment embankment and the body of the highway D1 at km 31,936 – 32,042. Due to the geological problems formed by the positions of low bearing compressible clays, a system of retaining structure, which is able to transfer high loads and absorb expected vertical and horizontal deformations, was preferred. The wall is 246 m long and reaches a maximum height of 7.5 m. The wall is along height divided by a berm with variable width, the maximum height of one stage is 4.5 m. Inclination of face of the wall is 80 degrees.
As a most appropriate systems of retaining wall was selected TerraMesh system – consisting of gabion face element with an integrated reinforced mesh. The fascia of Terramesh system is formed by gabion with dimensions 2.0 × 0.5 × 0.8 m and a horizontal reinforcing panel from a double-twisted steel mesh with a long-term tensile strength of 39.5 kN/m. The wire coating of the mesh is made of Zn + 5% Al + PVC. Gabion face and horizontal reinforcement are connected already in the production process and form an integral part of the system. The external stability of the reinforced wall is ensured by monoaxial geogrids ParaGrid 100/05 with a length of 6 – 12 m and a long-term strength of 63.3 kN/m. Due to overall stability issues and potential settlements of the reinforced retaining wall, including the embankment body, remediation measures had to be used. Their aim was to ensure the overall stability of the embankment as well as sufficient bearing capacity of the subsoil and to create conditions for accelerated consolidation of the subsoil. Remediation measures consisted of the replacement of the subsoil with a thickness of 1.5 m and with the additional system of gravel trenches with a width of 1.0 m and a depth of 1.5 m. To ensure overall stability two layers of monoaxial ParaGrid 200/05 geogrids with a length of 16.5 – 32 m were implemented.