Denmark's First Metro System

A new mass transit system, the Copenhagen Metro, has been planned to connect the central part of Copenhagen and restad. The contract for the detailed design and construction of the first phase of the Copenhagen Metro was signed in October 1996. The construction of the tunnels and underground stations could affect the stability of buildings and lead to formations of cracks resulting in structural damage unless adequate precautions are taken during the design and execution of the works. The key element in the control of risk of settlement damage is to adopt construction methods that minimise the likelihood of significant ground movement. The requirements led to a design based on tunnelling with earth pressure balance tunnel-boring machines and underground station excavations within retaining walls of secant piles, protected by grout curtains and grout blankets.