Cut and cover tunnels

Photo: COWI
Cut and cover tunnels are technically and economically optimal for tunnelling at shallow water depths in urban areas

Cut and cover tunnels at low depth have been used worldwide for centuries. However, new technologies now allow the use of cut and cover technology at increasing depths and very close to, or even under, existing tall buildings.

Advantage of cut and cover tunnels

In locations with no important constraints on the surface cut and cover tunnels are inexpensive compared to other tunnelling techniques. Approaches to immersed or bored tunnel sections will often be constructed as cut and cover tunnels.

Design of cut and cover tunnels

COWI's design of cut and cover tunnels is supported by intensive use of software developed in-house for all design phases:

  • The tunnel alignment shall minimise clashes with surface buildings, utilities, traffic, etc.
  • Alternative construction techniques for retaining walls are analysed
  • Special techniques developed coping with groundwater during construction
  • Structures are designed to minimise quantities.

Construction techniques

Several construction techniques exist and will be chosen depending on the ground conditions, the space available and depending on environmental requirements.

LAST UPDATED: 03.02.2017