What Does Segmental Concrete Tunnel Liners Mean?
Segmental concrete tunnel liners are prefabricated structural support pieces that are combined to form a complete tube along tunnel passageways. The segments are created in manufacturing plants for specific tunnel projects. These materials are commonly used in very large trenchless construction operations.
Trenchlesspedia Explains Segmental Concrete Tunnel Liners
Tunnel lining is used in both trenchless construction and rehabilitation to maintain the shape of the tunnel and to shield whatever might pass through it. Concrete, especially with steel fiber reinforcement, has proven to be an effective material in the formation of structures, from buildings to bridges to tunnels. The ability to shape concrete for specific uses makes it a versatile option for the trenchless construction industry.
The manufacture of a concrete tunnel liner segment begins with the specifications for the concrete mix. Not only are the type of concrete and the selection of reinforcement fiber important, it is also necessary to plan for and manage the amount of water to be used in production. The concrete should be wet enough to be inserted into molds, but dry enough to harden with the right consistency.
Each segment is created using molds that are heated to specific temperatures and for a preordained amount of time. Once dry, quality control testing confirms whether a segment is fit for use. Finished segments are labelled and numbered for database control. Large tunnel projects might require many thousands of these segments.
The installation of concrete tunnel liner segments might be performed by special machines, or they could be done by tunnel boring machines during the boring process. Properly placed concrete tunnel liner segments may be part of a tunnel that could last for centuries.