Dimensioneringsprinciper och kontraktsformat för injektering: verifiering av gränstillstånd och GBR (etapp 1)

Project name: Dimensioneringsprinciper och kontraktsformat för injektering: verifiering av gränstillstånd och GBR (etapp 1)
Project leader: Johan Spross, Soil and Rock Mechanics
Participating Project Partners: Trafikverket, Trieng AB, Göteborgs universitet
Project period:2025-02 till 2028-02
Funding: BeFo, Stiftelsen för Bergteknisk forskning

Grouting work to prevent inflowing groundwater is a significant part of Swedish tunnel projects. It contributes to a large part of both construction cost and construction time. The reported experience from completed tunnel projects indicate a difficulty to succeed with the grouting design as well as considerable uncertainties regarding the achieved watertightness. Considering the expected publication of the second generation of Eurocode 7 during 2024, we note that geotechnical design now mandates a formal verification of limit states also for groundwater control measures, although for now limited to structures above ground. It is however likely that this will be the case also for underground construction in rock in the foreseeable future. In addition to expectations on grouting design, we see also a need to allocate better the economic risk of grouting works between the client and the contractor. In a dialogue with the Swedish Transport Administration, it became clear that improved contracts and tender documents constitute a prioritized research issue for them.
This PhD project aims to develop novel design principles for grouting of tunnels that applies verification of limit states to ensure quality. The results are intended to be used as a scientific basis for the planned new European design standard for underground construction. This application contains Part 1 of a PhD project (until a licentiate degree). In addition, the project contains a separate senior research module that investigates the applicability of the international contract document Geotechnical Baseline Report, GBR, to Swedish rock grouting.