Transport infrastructure / Urban Railway
Project
Designs for Athens Metro Line 4, Section A: Alsos Veikou – Goudi
Location: Athens
Client: J&P AVAX, GHELLA SPA and ALSTOM TRANSPORT / ATTIKO METRO S.A.
Date: 2021 – 2029
Construction costs: approx. € 1.51 billion
Technical Details
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 total length of the section is approximately 12.8 km and it includes fifteen (15) new underground stations, nine (9) intermediate and/or terminal shafts, TBM double track tunnel approximately 10,300 m long, underground single-, double-, triple-track and turnout tunnels bored by conventional mechanical means, two forestations, and Operation Control Center.
Obermeyer was appointed by the Design & Build Contractor as the nominated Consultant for Geotechnical Evaluation, Temporary Excavation Support Design, TBM Tunnel Design, NATM Tunnel Works Design, Architectural and Structural Design of Stations / Shafts. The scope included the provision of geotechnical, tunnel, architectural and structural engineering services for the following stations, shafts, and associated structures:
1. Tunnels bored based using Tunnel Boring Machines (TBM).
- Total length 10,300m
- Precast segment ring’s outer diameter / inner diameter 9.18m / 8.48m
- EPB TBM bore diameter 9.52m
2. Veikou Shaft and Forestation
- 5-level Cut-and-Cover Forestation
- (-1) Personnel and maintenance areas
- (-2) Maintenance / repair areas of the rolling stock systems and E/M installations for Line 4
- (-3) Storage and E/M installation areas for Line 4
- (-4) A 4-track wide track level, including washing plant and track for train maintenance and repair of failures
- (-5) Level of rain-water, sewage, fire fighting and E/M equipment tanks for the washing plant.
- 215.80m long – inner dimension, with variable net internal width ranging from 13.8m to 28.7m, 35m deep
3. Veikou over triple-track Forestation Tunnel
- 295m long, net inner width 14.30m
- It serves the stabling of Line 4 trains
4. Alsos Veikou Trumpet Tunnel
- 59m long, maximum net inner width 13.87m
- Tunnel section with variable cross section, bored underground, from a triple + track tunnel to a double track TBM tunnel.
5. EYDAP Shaft
- Ventilation, emergency exit and recess for traction power switchgear
- Net internal dimensions 4.0m x 10.9m, 26.63m deep.
- Shaft is connected to the forestation tunnel via a connecting tunnel. Moreover, the traction recess is also bored as part of the tunnel works.
6. Alsos Veikou Metro Station
- 5-level Metro Station being constructed using a mixed construction method.
- Platform section is bored using conventional means, while the remaining sections of the station and the entrances are constructed using the Cut and Cover method
- Main Cut and Cover shaft 26.00m x 37.60m, 28.10m deep
- Side platform NATM tunnel 80m long, net inner width 15.04m
- Crossover tunnel, entrance tunnels, stairs/escalators tunnels, ventilation tunnels >185m long of various cross sections
- Two (2) ventilation Cut and Cover shafts 9.75m x 27.00m, 21.50m deep, outside the Station outline.
- West entrance and the lift housing Cut and Cover structure 12.90m x 30.00m, 15.00m deep, outside the Station outline
7. Galatsi Metro Station
- 5-level Metro Station being constructed using a mixed construction method.
- Platform section is bored using conventional means, while the remaining sections of the station and the entrances are constructed using the Cut and Cover method
- Main Cut and Cover shaft 18.40m x 45.8m, 32.80m deep
- Side platform NATM tunnel 72.5m long, net inner width 15.04m
- Crossover tunnel, entrance tunnels, stairs/escalators tunnels, ventilation tunnels >240m long of various cross sections
- Two (2) ventilation Cut and Cover shafts 9.75m x 27.00m, 21.50m deep, outside the Station outline
- West entrance Cut and Cover structure 26.00m x 5.00m, 16.80m deep, outside the Station outline
8. Alexandras Metro Station
- 6-level Metro Station being constructed using a mixed construction method.
- Platform section is bored using conventional means, while the remaining sections of the station and the entrances are constructed using the Cut and Cover method
- Main Cut and Cover shaft 17.20m x 41.9m, 33.50m deep
- Side platform NATM tunnel 96.60m long, net inner width 15.04m
- Crossover tunnel, entrance tunnels, stairs/escalators tunnels, ventilation tunnels >310m long of various cross sections
- Ventilation Cut and Cover shaft 9.10m diameter, 37.50m deep, outside the Station outline and 40m long NATM ventilation tunnel with variable net internal width ranging from 8.00m to 14.90m.
- West entrance Cut and Cover structure 27.50m x 6.00m, 17.20m deep, outside the Station outline
9. Exarchia Metro Station (Geotechnical design services only)
- 4-level Metro Station being constructed using a mixed construction method.
- Partial side platform NATM tunnel, net inner width 15.04m
- Stairs/escalators tunnels of various cross sections
10. Evangelismos Metro Station
- Main Station of Athens Metro Line 4, Section A. Interconnects to Evangelismos Station of Athens Metro Line 3.
- Five (5) functioning levels are configured in the Cut and Cover section: a) Ticketing level and tunnel ventilation shaft, b) Transfers, connection with the existing Line 3 Station and E/M areas level, c) E/M areas level, d) Platforms level and e) Tracks level.
- Partial side platform NATM tunnel , net inner width 15.04m
- One ventilation shafts 9.75m x 27.00m, 21.50m deep, outside the Station outline.
11. Panepistimioupoli Metro Station
- 4-level Metro Station being constructed using a mixed construction method.
- Platform section is bored using conventional means, while the remaining sections of the station and the entrances are constructed using the Cut and Cover method
- Main Cut and Cover shaft 29.80m x 57.30m, 32.20m deep
- Side platform NATM tunnel 52.00m long, net inner width 15.04m
- Crossover tunnel, entrance tunnels, stairs/escalators tunnels, ventilation tunnels >300m long of various cross sections
- Ventilation and south entrance Cut and Cover shaft 20.65m x 28.61m, 29.20m deep, outside the Station outline
- West entrance Cut and Cover structure 11.62m x 37.72m, 19.10m deep, outside the Station outline
12. Ilissia Metro Station (Geotechnical design services only)
- 7-level Metro Station being constructed using a mixed construction method.
- Platform section is bored using conventional means, while the remaining sections of the station and the entrances are constructed using the Cut and Cover method
- Main Cut and Cover shaft 35.10m x 37.05m, 46.00m deep
- Side platform NATM tunnel 67.50m long, net inner width 15.04m
- Crossover tunnel, entrance tunnels, stairs/escalators tunnels, ventilation tunnels >350m long of various cross sections
- One ventilation Cut and Cover shaft 9.75m x 27.00m, 21.50m deep, outside the Station outline
- Two (2) North and South entrance Cut and Cover structures 5.00m x 26.00m, 19.00m deep, outside the Station outline.
13. Goudi Metro Station
- 6-level Metro Station being constructed using a mixed construction method.
- Platform section is bored using conventional means, while the remaining sections of the station and the entrances are constructed using the Cut and Cover method
- Main Cut and Cover shaft 33.80m x 55.60m, 33.00m deep
- Side platform NATM tunnel 55.50m long, net inner width 15.04m
- Crossover tunnel, entrance tunnels, stairs/escalators tunnels, ventilation tunnels >270m long of various cross sections
- Ventilation Cut and Cover shaft 29.00m x 12.20m, 24.20m deep, outside the Station outline
- SW entrance Cut and Cover structure 20.0m x 43.30m, 17.40m deep, outside the Station outline
- North Entrance Cut and Cover structure 6.80m x 33.30m, 17.80m deep, outside the Station outline
Services Provided
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 (retaining system of stations, shafts etc.)
- Final Designs and Detailed Designs and analysis of tunnels bored using conventional mechanical means
- 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 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
- Waterproofing Designs and installation schemes
