We cover all project phases such as feasibility studies, conceptual design, preliminary design, detailed design, tendering and contract, supervision, and operation and maintenance.

Our design processes are lead by experienced project managers to ensure an optimum implementation of the projects. We work closely with our customers, neighbouring project owners, consultants and external specialists, local authorities, and utility owners.

Our tunnelling expertise

Ramboll covers the following areas:

• Tunnel design
• Rock mechanical calculations
• Geotechnical investigations and evaluations
• Groundwater handling
• Environmental investigations
• Ventilation design
• Fire design
• Mechanical and electrical installations
• SCADA
• Risk management
• Supervision
• Operations and maintenance management.

Solutions in tunnel engineering

Ramboll provides high standard, multidisciplinary solutions for all types of underground structures including cut and cover, immersed, jacked, bored, NATM, and hard rock tunnels. Furthermore, we are experienced in special disciplines, such as tunnelling under and close to existing structures, permanent diaphragm walls, top-down methods, etc. The preliminary investigations involve a range of different disciplines; frequently, a thorough preliminary investigation is key to a successful project. Our tunnel engineering work covers investigation, preconstruction, and construction phase investigations. These stages include primary site exploration, detailed surface investigations, detailed sub-surface investigations, and tunnel mapping.

General tunnel engineering

We cover all types of tunnel engineering, including:

• Cut and Cover tunnels
• Immersed tunnels
• Bored tunnels with TBM
• The New Austrian Tunnelling Method (NATM) tunnels
• Rock tunnels.

We have extensive experience with land tunnel and sub-sea tunnel projects, and we work on all phases of tunnels and large cavern engineering projects:

• Primary site exploration
• Detailed surface investigations
• Detailed sub-surface investigations and tunnel mapping
• Preliminary field investigations
• Main investigations
• Tunnel mapping based on Q-method
• Rock-support
• Grouting
• Problems caused by water
• Ventilation design.

Tunnels in soft soils

For tunnels and other underground structures in soft soils, we use different types of retaining and stabilising methods, including:

• Secant pile walls
• Diaphragm walls
• Sheet pile walls
• Ground anchors
• Reinforced soil
• Driven piles.

Tunnel safety

In recent years, there has been increased focus on tunnel safety, and international standards are currently under development. Ramboll carefully keeps track of these standards, and we continuously upgrade our services to provide the latest knowledge in tunnel safety within the following areas:

• Ventilation requirements for air quality and safety 
• Fire fighting access analysis. Evaluation of the fire fighting access for tunnels. This includes simulations of the conditions that can be expected during a fire.
• Fire and smoke spread analysis. Evaluation of the conditions within a tunnel during a fire, used in conjunction with the Evacuation Analysis. Serves as input for the Risk Analysis.
• Evacuation modelling.