Athens Metro Line 4

Section Α’ “Alsos Veikou – Goudi” has been planned so as to serve several densely populated areas of Athens, as well as important buildings and facilities such as hospitals, educational institutions, courthouses, and buildings of public organizations or ministries.

The geotechnical engineering services encompass:

• Elaboration of geotechnical reports and interpretative models to characterize ground conditions as well as geotechnical risk assessment.
• Reports on the Evaluation of Geotechnical Design Parameters
• TBM Tunnels Interstations Designs
• Design of TBM Tunnel Precast Concrete Lining Segments
• TBM Tunnels Back Analyses
• Designs of TBM Tunnel Interfaces
• Final Designs and Detailed Designs and analysis of Temporary Structures for 8 NATM / C&C Stations (retaining system of stations, shafts etc.) a major forestation and a ventilation shaft.
• Final Designs and Detailed Designs and analysis of metro tunnels bored using conventional mechanical means (355m long, triple-track)
• Detailed designs of associated works (steel struts, retaining walls, tunnel linings etc.)
• Estimation of ground settlements and displacements due to deep excavations and tunneling works in urban environment. 

The architectural engineering services encompass:

• Final Designs and Detailed Designs of architectural works and architectural finishes of buildings/structures for 6 metro stations a major forestation and ventilation shaft including:

  • Operational layouts of stations and buildings
  • Horizontal and vertical connections (corridors, escalators/staircases, lifts, emergency exits) ensuring, on the one hand, the smooth passenger flow and, on the other hand, the evacuation of stations and buildings in emergencies.
  • Architectural finishes on the floors (including provisions for PWD), masonry walls, roofs, balustrades, handrails, exterior surfaces of stations, entrances, shafts, crossovers and buildings
  • Reinstatement and configuration of the surfaces at street level at the locations of worksites
  • Operation equipment for the Station Master Rooms and the personnel areas in station

The structural engineering services encompass:

• Final Designs and Detailed Designs of permanent structures, such as Tunnels, Stations, Shafts and Depot buildings for 6 metro stations a major forestation and ventilation shaft.
• Waterproofing Designs and installation schemes

Technical details:

• Total TBM double track tunnel length 10,300 m, EPB TBM bore diameter 9.52 m

• 4- or 5- or 6- or 7- level metro stations being constructed using a mixed construction method (Platform level bored using conventional means (NATM), while remaining sections of station and entrances constructed using the Cut and Cover method

  • Side-platform NATM tunnels ~80 m long, net inner width >15.00m
  • Crossover tunnels, entrance tunnels, stairs/escalators tunnels, ventilation tunnels
  • Entrance and Ventilation Cut and Cover shafts
• 5-level Cut-and-Cover Maintenance Forestation 215.80 m long – inner dimension, 13.8 m to 28.7 m wide, 35 m deep
• Triple-track Forestation Tunnel, 295m long, net inner width 14.30 m
• Trumpet Tunnel, 59m long, maximum net inner width 13.87 m
• Shaft for Ventilation, emergency exit and recess for traction power switchgear