TIGHT - True Improvement in Grouting High pressure technology for Tunnelling

The underground has to some extent provided a solution to deal with increased urbanisation and a steadily growing number of mega cities around the world, particularly related to traffic problems. Tunnelling and tunnelling processes are becoming important issues for the purpose of materializing such underground use development. One important element of tunnelling in urban areas or elsewhere where a strict requirement applies for water control is the technique of rock mass grouting. Norway is one of the countries globally that has been the driver for this, on the other hand the technology is mainly empirical based. Rock mass grouting is a common method for reducing water inflow in tunnelling projects in hard rock, using cementitious grouts being carried ou t during excavation. The cost related to grouting constitute 20-30% of the tunnelling costs in projects where the groundwater level must be maintained at a certain level due to urban areas and/or in order to prevent damage to the environment. However, the re is a significant unforeseeable aspect of grouting for all parties involved which needs to reduced. Increased knowledge is therefore crucial for optimising the existing grouting methods by reducing the amount of grouting materials used and the time spen t on grouting operations. The proposed project TIGHT (True Improvement in Grouting High pressure Technology for tunnelling) will result in research that produces more cost- and time-effective grouting methods that will benefit all the participants in this research project, including the public owners who finance the building of road- and railway tunnels through the national budget. Other owners and operators of tunnels and underground openings will benefit from the results of TIGHT as well. The project has engaged cooperation with Korea, Sweden and Singapore. SINTEF, NGI and NTNU are research partners; industry partners are Normet Norge AS, GMA, BASF Norge AS, Rescon Mapei AS, Andersen Mek. Verksted AS, Bever Control,LNS AS, Veidekke ASA and GeoVita AS. SVV and JBV represent public tunnel owners. Several work-shops have been arranged with both national and international participation. A total of 8 MSc-students have been associated with TIGHT. One PhD-candidate. A final workshop took place in June 2018 gathering 85 participants with interest in grouting.

På kort sikt er det ikke lett å se effekten og virkningene av TIGHT. Prosjektet har benyttet anledningen til å bruke både vitenskapelige kanaler og populærvitenskapelige talerør for å spre funn og kompetanse i Norge og internasjonalt. Prosjektet er av den oppfatning at kompetansen må arbeides inn i bransjen, kompetansen må aboserberes og modnes i bransjen og først etter noen (1-4 år) tror vi at resultaten fra TIGHT er bearbeidet inn i stor tunnelprosjekter i Norge. Dette skyldes også at hele syklusen i et tunnelprosjekt er betydelig, 5-10 år fra planlegging starter til et prosjekt er ferdigstilt. Prosjekter som er i startgropa i 2018 vil ha lang tid før det er i bygging. Funnene våre er interessante, bransjen deler denne oppfatningen, men bransjen endrer kurs like tregt som Titanic gjorde.

Rock mass grouting is a common method for reducing water inflow in tunnelling projects in hard rock, using cementitious grouts being carried out during excavation. The cost related to grouting constitute 20-30% of the tunnelling costs in projects where th e groundwater level must be maintained at a certain level due to urban areas and/or in order to prevent damage to the environment. However, there is a significant unforeseeable aspect of grouting for all parties involved which needs to reduced. Increased knowledge is therefore crucial for optimising the existing grouting methods by reducing the amount of grouting materials used and the time spent on grouting operations. Current understanding of how rock mass grouting is carried out efficiently is limited . There are many questions yet to be clarified, such as: How is the grouting equipment functioning; How is the grout material behaving; and How is the rock mass reacting? From these 3 main questions the details of TIGHT will be developed. In Norway and a lso in other Scandinavian countries rock mass grouting has been applied as an integrated part of the tunnelling process. However, different approaches prevail. The similarities and differences of grout works as performed in neighbouring countries Sweden a nd Norway can be concluded with amongst others things that: In short it is possible to draw some distinct differences between the practices in Sweden and Norway and in the following we propose that; the Swedish approach is to a large extent theoretically based, and the Norwegian approach is to a large extent empirical based. TIGTH will improve our position. The companies and participants involved represent the entire value chain for rock mass grouting for tunnelling and understanding the needs of the ind ustry. TIGHT (True Improvement in Grouting High pressure Technology for tunnelling) will result in research that produces more cost-and time-effective grouting methods, and provides research based innovovation.