Tunnel Grouting: Engineering Methods for Characterization of Fracture Systems in Hard Rock and Implications for Tunnel Inflow
Doctoral thesis, 2011

In tunnel construction in hard rock, a common method to reduce water inflow is to perform pre-grouting. The grouting design should be adapted to the current rock mass conditions as well as the stated inflow requirement for the tunnel project. The aims of the research project have been to increase the understanding of water-bearing fracture systems in three dimensions for grouting; to suggest methods for characterization of fracture systems (tests and their interpretations) so that data relevant for tunnel grouting are obtained; and to improve the method of inflow prediction so that important geological aspects, such as three-dimensional fracture networks, can be incorporated. This has been done by developing a conceptual model for water-bearing fracture systems in hard rock for grouting purposes. A study of parameters of central importance for this has been done, followed by a study of tests suitable to supply this information. Consequences of different fracture systems on grouting results have been discussed, and ways to adapt grouting design are suggested. As integrated parts of this a number of case studies have been analyzed. The major conclusions are: A relevant conceptual model of the rock mass is a good basis for grouting design and inflow prediction. Awareness of anisotropy is important: identification of the orientations of water-bearing fracture sets is essential both for inflow prediction and for grouting design. A statistically based decision method is suggested for the construction stage, to determine whether or not a tunnel section needs grouting.

fracture system

anisotropy

flow dimension

hydraulic tests

hydraulic aperture

transmissivity

grouting

fractures

rock mass

VF
Opponent: Jonny Rutqvist

Author

Lisa Hernqvist

Chalmers, Civil and Environmental Engineering, Geology and Geotechnics

Numerical modeling of grout spread and leakage into a tunnel in hard rock – a case study

World Tunnel Congress - 2008: Underground Facilities for Better Environment & Safety - India,;Vol. 1(2008)p. 482 - 491

Paper in proceeding

Geology, water inflow prognosis and grout selection for tunnel sealing: Case studies from two tunnels in hard rock, Sweden

ITA-AITES World Tunnel Congress. Vancouver, Canada, Maj 17-19,;(2010)

Paper in proceeding

Analyses of the grouting results for a section of the APSE tunnel at Äspö Hard Rock Laboratory

International Journal of Rock Mechanics and Minings Sciences,;Vol. 46(2008)p. 439-449

Journal article

Areas of Advance

Building Futures (2010-2018)

Subject Categories

Civil Engineering

ISBN

978-91-7385-597-6

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 3270

VF

Opponent: Jonny Rutqvist

More information

Created

10/7/2017