A Swedish grouting design concept: Grouting with silica sol in the Nygård and Törnskog tunnels
Paper in proceedings, 2012

The scope of this paper is to present two tunnel grouting design case studies where the waterproofing aimed not only to reduce the water inflow to a specified level, but to minimize the number of dripping spots by means of pre-excavation grouting. Every grouted section of around one hundred meters in both tunnels used relevant parameters from the rock and the grout material properties to develop an adequate, pre-excavation grouting design. Both tunnels, constructed in crystalline rock, used silica sol as the main grouting material and were evaluated later by means of control boreholes and dripping characterization. Control boreholes showed a decrease in the transmissivity in these sections, and the dripping characterization showed a reduction in the number of dripping spots compared to the rest of the tunnel, where this pre-excavation grouting concept was not used. This led to minimization of the number of drains used, which was clearly visible in the Nygård case, suggesting that the designs were successful and confirming that an understanding of the rock and grout properties is crucial to the design concept.


Christian Butron

Chalmers, Civil and Environmental Engineering, GeoEngineering

Gunnar Gustafson

Chalmers, Civil and Environmental Engineering, GeoEngineering

Johan Funehag

Chalmers, Civil and Environmental Engineering, GeoEngineering

Geotechnical Special Publication

0895-0563 (ISSN)

228 GSP 826-835

Subject Categories

Geophysical Engineering

Other Earth and Related Environmental Sciences

Areas of Advance

Building Futures (2010-2018)






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