Abstract:

The Norwegian Public Road Administration (NPRA) needs to keep a good and consistent overview of the rock mass, rock support and geometry in their 1.000 existing road tunnels as well as the additional 20 to 30 tunnels which are excavated each year. In a software, geological registrations from each blast round are linked with interpreted drill hole parameters and rock support data as it is installed in the tunnels. A compiled data set of all relevant data makes an important decision basis for the dimensioning of the permanent rock support. The research and development programme "Modern road tunnels" has throughout the period 2008 – 2011 developed a unified strategy for road tunnels owned by NPRA. The programme included systems for tunnel documentation as a work package after some previous incidents of rock failure inside some tunnels. Subsequent analysis unveiled the need of improved routines and tools in order to obtain as precise design criterions as possible, and to archive data for a future rehabilitation of the runnels. This strategy includes guidelines for the collection of relevant documentation of the rock mass as the building material in which the tunnels are excavated, rock classification and associated rock support, water and frost isolation vaults, interpretation of drill hole parameters, and upload of photos, blast reports and laboratory test documents. New functionality comprising import of scan data and background images was released the autumn 2011. Some benefits of the new routines and software tools are more optimized interrelationship between the geological premises and the tunnel construction, more standardised drawings and sketches which are easily understood by any geologist and controller throughout the country and more convenient access to data reports and as-build drawings. Future development should include further treatment of all data in a tunnel data bank.

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