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Underground car park – World Trade Organization (WTO) – Switzerland

Underground car park – World Trade Organization (WTO) – Switzerland

Tunnels and underground structures

  • Project Owner : Département de l’Urbanisme (Ville de Genève)
  • Mission : Maîtrise d’œuvre complète
  • Cost of the works : 29’000,– kCHF
  • Cost of the mission : 805,– kCHF
  • Mission date : 2011-2015


This project involved the creation of a car park for the World Trade Organisation (WTO). It comprises four levels of underground parking (400 spaces) and will be able to accommodate an 8-storey superstructure building.

The site is bordered by the SBB tracks and the World Meteorological Organisation (WMO), and is located in a dense urban area undergoing major change. For this project, we had to take account of neighbouring projects and analyse their influence on the design of the structure and the phasing of its construction, among other things.

The main challenges of the project were as follows

  • Protecting the water table (piezometric monitoring, trouser-leg walls),
  • Evacuation of polluted land (establishment of a precise earthworks phasing to avoid polluting healthy land).
  • Carrying out a worksite in a dense urban environment,
  • Construction of a deep excavation alongside existing buildings and existing railway lines.

Technical specifications :

  • Car park enclosure in 60 cm thick diaphragm wall (5,560 m2)
  • Active anchors (3T15S) (200 anchors and 2,500 ml of boreholes),
  • Heavy shoring of the excavation enclosure,
  • Excavation of polluted sites (around 45,000 m3),
  • Casing below the water table for the top 2 levels of the car park,
  • Concrete (7,500m3), Reinforcement (800 tonnes).


As civil engineer and leader of the multidisciplinary consortium, GEOS carried out a complete project management mission including the following services:

  • Preliminary design,
  • Final design,
  • Application for planning permission,
  • Invitation to tender,
  • Construction project,
  • Construction management,
  • Commissioning and completion.



Posted on

27 July 2023