The art of tunnel rehabilitation includes many facets, from inventory inspection and data recording, through interpretation and analysis, to the design for repair and facility enhancement.
One of the key challenges is that we rarely know the existing conditions and level of detail required to complete the assignment. This requires a careful and thoughtful approach to gathering and synthesizing information as investigations and incremental lining removal and replacement proceeds.
Lining distress can manifest itself as relatively small-scale degradation or as larger-scale deformation. Understanding the cause and effect relationships that tend to drive the degradation of lining quality and larger scale deformations is key to solving problems when faced with a paucity of information.
Mott MacDonald's experience involves projects including tunnels lined with brick, cast-in-place concrete, timber linings, cast-iron segmental linings, and immersed tube tunnels.
Whether enhancing clearance for 30 railroad tunnels through West Virginia and Virginia, inspecting some of North America's oldest subway tunnels in Boston, or rehabilitating sewer tunnels in Cleveland and southern California, Mott MacDonald can deliver the right approach.
Our rehabilitation-related capabilities include the following:
- Tunnel structure repair
- Internal structure reconstruction
- Tunnel waterproofing
- Operational & functional changes
- Enhanced facilities
- Improvements to safety
- Upgrading of equipment installations
- Improved ventilation
- Geometric enlargements to increase operational clearance
- Additional openings such as cross passages