3316
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
2.5
Drainage capacity
The Terzaghi criterion D
15f
/d
85b
≥ 4 still applies and Sherard
recommends D
15f
≥ 0.2 mm.
Casagrande, A. 1950. Notes on the Design of Earth Dams.
J. Boston
Soc. Civil Eng.
Oct. 1950, Vol. 37.
DeMello, F. 1975. Some lessons from unsuspected, real and factitious
problems in earth dam engineering in Brazil.
6
th
Regional Conf. on
Soil Mech. & Found. Eng.
, South Africa (11): 304ff.
2.6
Material durability
The durability of filter materials is typically investigated with
standard tests such as the Los Angeles abrasion test (ASTM
C535) or the wet and dry strength variation (typical
limit ≤35%).
However, for important dam structures a mineralogical and
chemical investigation of the dam material is recommended.
This can highlight if the material has inclusions of (i) swelling
clay
minerals
or
(ii)
minerals
which
dissolve
in
water,
e.g.
gypsum
or
carbonate
rocks. Latter materials
cannot
just
dissolve
but
also
re-cement
at
the
particle
contacts
and
create
true
cohesion. Materials with carbonate and sulphide content should
be used with care for dam filter materials.
Foster M. & Fell R. 1999.
A framework for estimating the probability of
failure of embankment dams by internal erosion and piping using
event tree methods.
UNICIV Report No. R-377, School of Civil and
Environmental Engineering, Univ. New South Wales, Sydney.
Kenney, T.C. & Lau, D. 1985. Internal stability of granular filters.
Can.
Geotech. J.
(22): 215-225.
Kenney, T.C. & Lau, D. 1986. Internal stability of granular filters.
Reply.
Can. Geotech. J.
(23): 420-423.
Messerklinger,
S.,
Brenner,
R.P.
&
Zegele,
Z.
2010.
Safety
and
Maintenance
Issues
for a Long Embankment on a Karstic Foundation
under Artesian Pressure.
2
nd
Int. Conf. on Dam Maintenance and
Rehabilitation
, Zaragoza: 325-334.
Messerklinger, S., Straubhaar, R., Brenner, R.P., Herzog, R., Laue, J. &
Springman, S.M. 2011a. Large-Scale Cyclic Triaxial Tests for the
Seismic Safety Assessment of a high Earth Core Rockfill Dam.
15
th
ECSMGE
, Athen, 1171-1176.
Figure 2: Summary of filter criteria.
3 CONCLUSIONS
Water has a major influence on the stability and erosion
resistance of natural and man-made soil structures. Draining the
water out of the soil structure improves its stability. However,
draining of the soil has to be done in a controlled manner
without erosion. This is achieved with filter materials placed in
or on the soil structures. Filter materials have to have certain
properties which are described by filter criteria, significant
development of which took place during recent
decades.
Nowadays,
these
filter criteria are composed of six different parts
and for each of these criteria are defined which have been
discussed in this paper in detail.
Despite of all the efforts in filter design a significant number
of failures still occurs due to erosion. Embankment dam failures
are given e.g. in the ICOLD Bulletin “
Internal Erosion of
Existing Dams and their Foundation”.
About 4 of 10’000 large
dams fail per year and 2 of these failures are caused by internal
erosion. Overall about one embankment dam
in 180
fail during
its
lifetime.
A
recent
example
is
the
failure
at
the Prudencia hydro-power
plant
in Panama, where a homogenous dammade of
residual soils
failed at the contact to a concrete gravity structure. Neither in
the dam body or at the dam toe, nor at the contact to the rigid
concrete wall, was any filter material placed. This supported the
failure mechanism which was triggered in the first place
by
leakage
in
the geo-membrane sealing
(Messerklinger, 2013).
Although the design of filter materials and their application
to soil structures is tought in undergraduate classes and is well
known to geotechnical engineers, the lack of the design and
placement of filter materials still causes numerous failures.
Hence, further efforts on the selection of appropriate filter
materials and
their
incorporation
in soil structures are essential.
4 REFERENCES
Bertram, G.E. 1940.
An Experimental Investigation of Protective
Filters.
Harvard Soil Mech. Series No.7.
Bertram, G.E. 1967. Experience with Seepage Control Measures in Earth
and Rockfill Dams.
9
th
ICOLD Congress, Istanbul
, Vol. 3: 91.
Messerklinger, S., Brenner, R.P. & Zegele, Z. 2011b. Long-term
Seepage behaviour of an Embankment dam founded on Rock Strata
under Artesian Pressure.
Int. Symposium on Modern Technologies
and Long-term behaviour of Dams
. Zhengzhou, China: 429-438.
Messerklinger, S., Aemmer, M. & Straubhaar, R. 2011c. Heightening of
the Göscheneralp Earth-core Rockfill Dam.
Int. Journal on
Hydropower & Dams
, 8(3): 43-50.
Messerklinger S. 2012. Erosion and Drainage Well Blowout in the
Foundation of
the Plavinas Powerhouse: Case History.
Geotechnical
and Geological Engineering Journal
. 30(6): 1421-1433.
-
20
40
60
80
100
0.06
0.6
6
60
Messerklinger S. 2013. Failure of a Membrane-Lined Embankment
Dam – Case Study. Submitted to
Geotextiles and Geomembranes
.
Milligan, V. 2003. Some uncertainties in embankment dam engineering.
ASCE.
129(9): 785-797.
Patrashev A.N., Pravedny G.K. 1965.
Manual on designing of reverse
filters for hydroengineering structures.
VSN-02-65/GPKE.
Pavlovsky N.N. 1922.
Theory of underground water motion beneath
hydroengineering structures and their foundations and its basic
application.
Research Land Reclamation Institute. St. Petersburg.
Pravedny G.K. 1976.
Guideline on calculation of seepage strength of
dams made of soil materials.
P-55-76/VNIIG. Leningrad.
Sherard, J.L., Woodward, R.J. & Gizienski, S.F. 1963.
Earth and Earth-
Rock Dams – Engineering Problems of Design and Construction.
John Wiley and Sons, New York.
Sherard, J.L. 1972.
Embankment Dam Cracking.
In Embankment Dam
Engineering. John Wiley & Sons, New York: 271-348.
Sherard, J.L. 1979. Sinkholes in dams of coarse, broadly graded soils.
13
th
ICOLD Conf.
: 25-35.
Sherard, J.L., Dunnigan, L.P. & Talbot, J.R. 1984a. Basic properties of
sand and gravel filters.
J. Geot. Eng.
110(6): 684-700.
Sherard, J.L., Dunnigan, L.P. & Talbot, J.R. 1984b. Filters for silts and
clays.
J. Geot. Eng.
110(6): 701-718.
Sherard, J.L. & Dunnigan, L.P. 1985. Filters and leakage control in
embankment dams.
Proc. Symp. on Seepage and Leakage from
Dams and Impoundments. ASCE
, New York: 1-29.
Sherard, J.L. & Dunnigan, L.P. 1989. Critical filters for impervious
soils.
J. Geot. Eng.
115(7): 546-566.
Sutherland, K.J. 2002.
Quantifying and controlling segregation in earth
dam construction.
MSc Thesis, University of Toronto.
Terzaghi, K. & Fröhlich, O.K. (1936).
Theorie der Setzungen von
Tonschichten: Eine Einführung in die analytische Tonmechanik.
Deuticke, Leipzig.
Terzaghi, K. 1936. The Shearing Resistance of Saturated Soils
. Proc. 1
st
ICSMFE
28(3):54-56.
Terzaghi, K. & Peck, R.B. 1948.
Soil Mechanics in Engineering
Practice.
John Wiley&Sons, New York.
Vaughan, P.R. & Soares, H.F. 1982. Design of filters for clay cores of
dams.
J. Geot. Eng.
108(1): 17-31.
Vaughan, P.R., Kluth, D.J., Leonard, M.W. & Pradoura, H.H.M. 1970.
Cracking and erosion of the rolled clay core of Balderhead dam and
the remedial works adopted for
its repair.
10
th
ICOLD
, Q.36-R.5.
Self healing criteria
Ø0.075 mm < 5 ÷ 7 %
I
P
< 5 %; sandcastle test
Drainage criterion
D
15f
/d
15b
≥ 4
Filter criteria
(see Tab. 1)
Mass percent passing [%]
After Milligan 2003
Grain size [mm]
