This project is concerned with the implementation of the project titled "Restoration of sections affected by landslides on rural roads: Pyrgos–Oinoi (1000m before the junction of Outsochera), Simopoulo–Anthona (towards the settlement 'Kalo Paidi'), and Helidoni–Kryoneri (2000m before the entrance of Kryoneri)." It addressed the restoration of landslide phenomena that occurred in certain sections of the provincial roads.
For the restoration of the cross-section, approximately 157.00 meters long (including access to the project, e.g., embankments), the following works were carried out in their implementation sequence:
Deep replacement of superficial loose soil formations to a depth of at least 3.00 meters. The excavation is delineated by the slope of the area with a temporary slope of 1:1 (v:h), leaving a 2.50-meter-wide strip to ensure temporary traffic in the area.
In case locally loose soil formations were found below the final level during excavation, the depth may be increased with the consent of the Service and the designer. The final working floor was configured with a slope of 2% towards the embankment to limit the circulation of surface water from the free slopes and collect them through a transverse drainage.
Application of a drainage layer (ΣΣ) with a thickness of 50cm using selected granular materials according to ETEP 02-07-01-00, §3.1, with a passing fraction No200 < 7%. The construction was done in two layers of 25cm each, with the first layer compacted to refusal.
Application of separation geotextile to protect the drainage layer from the intrusion of fine-grained material from new backfills.
Construction of a pile row, length L=149.60m, with elements of diameter D=80cm at intervals of s=1.50m and an embedding depth of L=12.0m. The tops of the piles were restrained by a head beam measuring 1.0 x 1.0m, on which a retaining wall of height 3.50m was formed. Above the piles, separation geotextile was placed to protect them from fine-grained material of the embankment.
Construction of a longitudinal drainage channel towards the embankment of the retaining wall using a perforated pipe with a diameter of Φ400 adequately protected by separation geotextile and filled with coarse-grained materials. The outlet of the drainage channel was directed to a natural receiver outside the critical area. Backfilling of the trench with materials according to ETEP 02-07-01-00.
The final construction phase of the road included the configuration of pavement layers (two sub-base layers, each 10cm thick, and two base layers, each 10cm thick), the construction of two (2) asphalt layers, each 5cm thick, and the marking (vertical and horizontal) of the new road. The works were completed with the construction, above the retaining wall, of an open triangular trench for the drainage of surface water to natural receivers, aiming to relieve the area above the wall.
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