Underground Rehabilitation
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. HMM's experience involves projects including tunnels lined with brick, cast-in-place concrete, timber linings, cast iron segmental linings, and immersed tube tunnels. Such structures span the full array of tunnel applications, including rail, transit, freight, highway, water, wastewater, and pedestrian crossings.
One of the key challenges involved with the rehabilitation of underground structures 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. Experience and lessons learned are most valuable in such instances, which makes our long history of tunnel rehabilitation projects truly value-added.
Whether it's inspecting and implementing improvements to enhance clearance requirements for 30 railroad tunnels through West Virginia and Virginia, inspecting some of the oldest subway tunnels in North America in Boston, inspecting a number of "granddaddy" highway tunnels in Pennsylvania, or rehabilitating sewer tunnels in Cleveland and southern California, Hatch Mott MacDonald can deliver the right approach to investigation, evaluation, and analysis for the design and construction management of rehabilitation projects.
Our rehabilitation-related capabilities include:
- tunnel structure repair
- internal structure reconstruction
- tunnel waterproofing
- operational and 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
