Helping practitioners pinpoint defects in or behind tunnel linings
Mapping Defects In or Behind Tunnel Linings (R06G)
Tunnels are high-volume, limited-access environments that pose significant challenges to periodic structural evaluations. Keeping tunnels open during inspection and minimizing tunnel closures and user delays must be carefully balanced with the need to conduct detailed inspections – all while ensuring both driver and inspector safety. Nondestructive testing (NDT) technologies have the potential to achieve this balance.
SHRP2 researchers evaluated existing and emerging NDT technologies that may locate and characterize service-life defects in or behind shotcrete, concrete, and composite concrete and steel tunnel linings, including lining delamination, lining and groundmass voids, water seepage, and loose tiles and veneers.
The final report guides practitioners on the selection, operation, and application of specific NDT techniques applicable to a variety of tunnel linings and structure settings. Technical guidance is also included as part of the NDToolbox, an online collection of the best technologies to identify deterioration on concrete bridge decks, ensure that construction materials meet quality-control standards, and assess the condition of pavements and tunnels.
This project is currently transitioning from research to implementation via the Round 4 Implementation Assistance Program. A full product page will be available early in 2014
Additional information about this research project is available on the Transportation Research Board’s website.