2016-03-10
Geotechnics
- Client: ERE – EIFFAGE RAIL EXPRESS
- General Contractor: CLERE – CONCEPTION LIGNE EIFFAGE RAIL EXPRESS
- Assignment: Mission G2: Study of earthworks + foundations OA (design); Mission G4
- Total cost of work: €1,538k
- Completion date: 2011-2015
PROJECT DESCRIPTION AND CHARACTERISTICS
The high-speed line (LGV) Bretagne – Pays de la Loire is an extension of the LGV Atlantique Paris – Le Mans. It crosses the regions Brittany and Pays de la Loire and the departments of Sarthe, Mayenne and Ille et Vilaine. The total length of the route is 182 km plus 32 km of connection to the existing network. As part of its participation, GEOS worked on the 30km section B from Laval to Vitré.
ASSIGNMENT
GEOS conducted G2-AVP & PRO studies in the design phase. The studies include:
- definition, monitoring and control of geotechnical investigations;
- earthworks (stability of earthworks, reuse / recovery of materials, design specifications, geotechnical models);
- engineering structures (type of foundation, design specifications, etc.);
- the Vicoin estacade (an engineering structure consisting of nine spans with a total length of 260m).
The design mission was complemented by a supervision of geotechnical mission G4, including supervision of studies (VISA) and supervision of execution follow-up (DET).
2016-03-01
Geotechnics
- Client: RFF
- General Contractor: INGEROP
- Assignment: Assistance to the Project Manager
- Total cost of work: €12k
- Completion date: 2010 – 2011 studies 2013 – 2014 works
PROJECT DESCRIPTION AND CHARACTERISTICS
the railway crossing no.46 (PN 46) at the northern exit of the town of Sallanches, at the intersection of secondary road RD1205 (ex RN 205) and the railway line that connects La Roche sur Foron to Saint-Gervais les Bains. It is one of the 400 concerning PNs, identified by the Ministry of Infrastructure, RFF and SNCF, at the national level. In the chosen solution, the RD 1205 is slightly deflected and passes under the railway by a hopper and a lower passing way and joins the South roundabout. The structure is 225m long and about 15m wide. Because the groundwater level is located at a shallow depth and the permeability of the ground is high (gravelly alluvial deposits in Arve), the structure requires the use of a temporary sheet pilling support combined with a hydraulic plug at the bottom of the excavation. The final structure is a concrete open trench with a rail bridge in the middle.
ASSIGNMENT
GEOS conducted a G5 mission of expertise and geotechnical assistance within the meaning of the standard NF P 94-500.
These studies particularly addressed the following points:
- Definition of complementary geotechnical and hydrogeological investigation programs;
- Assistance to the project management for the piloting of the G2 mission, Project Phase carried out by an external geotechnical BE.
