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Geotechnical News • March 2014
51
THE GROUT LINE
2007) report that overall inflow rates
of less than 10 L/min/100 m have
been achieved with the application of
good pre-grouting practice. The many
instances of high grout volumes that
were required to achieve the relatively
low inflow rates indicate the existence
of high initial hydraulic conductivities.
Differences in grouting
philosophies
In short it is possible to draw some
distinct differences between the prac-
tices in Sweden and Norway and in
the following we propose that:
1. The Swedish approach is to a large
extent theoretically based.
2. The Norwegian approach is to a
large extent empirical based.
3. The Norwegian approach was
developed during extensive tun-
neling for hydroelectric power
development in a context where
the practical aspects governed
the grouting and then it moved to
urban tunnels.
4. The Swedish approach has been
directly applied in urban tunneling
and lots of experience on extreme
tight requirements from the un-
derground storage of radioactive
waste has been included.
5. The Swedish approach applies pre-
defined grout classes, however not
always directly related and adapted
to the actual rock mass conditions.
6. The Norwegian approach is based
on close cooperation at the tunnel
face and customizing the works
according to the encountered
conditions.
7. The Norwegian approach is
synonymous with high pressure
grouting.
8. The Swedish approach applies low
to moderate grout pressure.
9. The Swedish approach uses con-
tract type based on the amount
pumped.
10. The Norwegian approach is based
on full reimbursement according to
actual consumption.
The questions raised in the intro-
duction were: Is there any explicit
description on what pressure is the
correct to be applied in any given
circumstances; Can it be that several
different techniques, such as differ-
ent pressures can be applied giving
the same predetermined outcome?
Would it be a matter of functional
requirements as a result of the grout-
ing efforts? Or is it simply governed
by a number of other aspects that are
culturally based?
The paper addresses various aspects
related to Swedish and Norwegian
rock mass grouting aspects and con-
cludes that there are certain points of
distinction. The causes on why grout-
ing has developed in various direc-
tions in these two closely neighboring
countries are difficult to answer;
maybe it is a cultural difference but
for sure there is a difference in tunnel
development in the two countries. Still
the observant reader would have iden-
tified conformities; such as the drive
towards using stable grouts, increased
number of grout holes and the reliance
on cement based grout design. And
finally; we might agree that the result
of the sealing is not getting better or
worse using high pressures with data
shown in this paper.
References
Brantberger, M. (2009). Förfrågning-
sunderlag för injekteringsarbeten
i en utförandeentreprenad.BeFo
rapport 92. Stockholm 2009.
Beitnes, A. (2002). Lessons to be
learned from long railway tun-
nels. Water Control in Norwegian
Tunnelling, Publication No. 12,
Norwegian Tunnelling Society, pp
51-57.
Dalmalm T, 2004. Choice of grouting
method for jointed hard rock based
on sealing time predictions. Ph.D.
thesis, Royal Institute of Technol-
ogy, Stockholm
Garshol, K (2002). Modern grout-
ing techniques. Water Control in
Norwegian Tunnelling, Publication
No. 12, Norwegian Tunnelling
Society, pp 81-88.
.
Garshol, K (2003). Pre-excavation
Grouting in Rock Tunneling.
Grøv, E. (2008a). Water control in
Norwegian tunnelling. Proceed-
ings of South American Tunnelling
Congress 2008, Brazilian Tunnel-
ling Committee – CBT, Sao Paulo,
Brazil.
Grøv, E. (2008b). Control of seepage
in rock tunnels. ITA/AITES Train-
ing Course Tunnel Engineering
2008, Agra, India.
Grøv, E., Nilsen, B. (2007). Sub sea
tunnel projects in hard rock envi-
ronment in Scandinavia. Chinese
Journal of Engineering and Rock
Mechanics. Vol. 26 no. 3.
Gustafson, G., Stille, H. (2005) Stop
criteria for cement grouting. Fels-
bau 23, pp 62-68, Verlag Gluckauf,
Essen.
Tattersall, J. W., Grøv, E. (2009) Rock
Mass Groutability – Application
of Norwegian Experience to Hong
Kong. Hong Kong Tunnelling
Conference 2009
Vattenfall (1968). Anvisningar för
utförande av cementinjektering i
berg. Statens Vattenfalsverk 1968
Eivind Grøv
Chief scientist Professor SINTEF/
NTNU Trondheim, Norway
Johan Funehag
Assistant Professor, Chalmers Uni-
versity of Technology; Gothenburg;
Sweden
Thomas Janson
PhD Rock mechanics, Tyréns,
Gothenburg, Sweden
I hope you found this article interest-
ing, as I did, and if you have some
comments or grouting stories or case
histories, send them to me at:
Paolo Gazzarrini,
,
or
Ciao! Cheers!