Anchorage testing and monitoring

This article describes GRANIT, a new non-destructive non-invasive testing system designed to assess the integrity of anchorages in tunnels. The system is used to conduct quality control, exception testing, load and effective free length diagnosis, bond verification, and troubleshooting of anchors. The article describes how the system operates as well as the need for integrity testing. A discussion follows regarding how GRANIT was used in tests to ascertain unbonded length, determine loads for bolts, and locate any bonding issues. Long term monitoring of loads allows for trends to be observed, thus leading to the identification of potential problems.