Mott MacDonald has earned an international reputation for innovative cut-and-cover tunnel design solutions which complement recent and ongoing advances in construction methods. We’ve developed new approaches to these tunnel designs in both urban and rural locations.

Contract 423 on Singapore’s six-lane Kallang Paya Lebar expressway features 2.9km of 36m wide cut-and-cover tunnel The design and construction of cut-and-cover structures embraces the full range of foundation engineering techniques which we’ve employed throughout the world. Our leading edge skills in understanding the relationships between analysis, soil/structure interaction and the method of construction provides the basis to our design philosophy. Throughout the world we have played a key role on prominent and challenging projects in difficult ground conditions, from very soft alluvial deposits to over-consolidated swelling clays.

In designing any cut-and-cover tunnel – be it for railways, metros or highways – we pay particular attention to areas where benefits of speed, economy, ease of construction and added safety can be achieved. Measures to minimise traffic disruption during construction are always a major issue for urban environments and these have been successfully incorporated into our designs. We’ve also designed numerous special structures to stringent defence standards.

Our specialist skills in value engineering and our close liaison with contractors in design-build schemes have resulted in both innovative engineering solutions and considerable cost savings for both owner and contractor on many cut-and-cover tunnel schemes.

Our portfolio of major cut-and-cover tunnel projects include:

• Heathrow Express Rail Link, UK
• London's Limehouse Link and A13 East India Dock road tunnels, UK
• Boston Central Artery Tunnel, USA
• Delhi Metro, India
• Putrajaya Light Rail, Malaysia
• Kallang-Paya Lebar Expressway, Singapore

Tunnel portals for the Heathrow Airside Road Tunnel required excavation up to 17m deep