THE PROJECT
Construction by Bouygues Travaux Publics Croatia of a new road parallel to an existing one, in the middle of the Učka mountain range. There is therefore digging of a traditional tunnel of 6 kilometers in parallel with an existing tunnel. The two tunnels are connected by branches, which are more sensitive points. The aim is to check the stability of the existing tunnel in line with the branches and when drilling the branches.

The section to the right of the opening of the branch is measured by 9 positions, doubled to follow the longitudinal and transverse effort.

THE SOLUTION
Installation of 72 surface strain gauges on the concrete lining, as well as 24 shotcreted embeddable strain gauges. Some of the sensors have been moved to multiple positions after passing the critical points of survey.

THE OUTCOME
By adding many automatized strain measurement points, the Client benefits from a quicker monitoring of the branches, thus helping with a better controlled construction of the new tunnel.

This activity will also reduce the number of manpower hours required to monitor the locations ensuring the containment of operating expenses and the extension of the lifespan of the structure.