Analysis of a large deep-seated creeping mass movement
using GIS and DEM
M. Weißflog Geoconsult ZT GmbH, Salzburg/Austria Prof. Dr. K. Thuro Technical University of Munich, Munich/Germany
Dr. Ch. Zangerl alpS Centre for Natural Hazard and Risk Management, Innsbruck/Austria
Introduction
Morphological Structures of the Study Site
In 1939 Ampferer described slow but very
large mass movements, which he found all
over the Eastern Alps. Stini extended this
topic 1941 under the name “Talzuschub”
(so called valley close-up) and turned it into
an engineering challenge by drawing
attention to the constructive consequences
despite the hardly measurable slope
deformations.
Since terminology varies to a large extent in
international scientific literature, the terms
“compound sagging” (according to
Hutchinson 1988) or “rock flow” (according
to Varnes 1978) will be applied for complex
large mass movements.
Figure 6: Typical irregular physiography of the
spreading area. Because of lateral spreading small
grabens diagonal to the slope line accumulate, so
called „Nackentälchen“.
Figure 9: Gneisses of the upper part of the mass
movement. The photo shows the highly fractured and
disaggregated character of the material. Only very few
areas with relatively intact rock mass are observed.
Figure 8: View from the Stupfarri crest into the northern
Kauner and Inn valley. Numerous double ridges can be
observed at the Stupfarri ridge.
Figure 7: Closer view into a diagonal valley in the area
of spreading. This valley is around 2,5 m deep.
Vienna
Munich
Figure 1: Map of Austria (grey). Arrow shows the
location of the study site.
N
Figure 5: Hillshade calculated from an airborne
laserscan clearly shows the formation of slabs within the
landslide. Light colors show the more even areas.
Compare with Figure 14. (Reference: LIDAR height model,
Figure 10: Possible shear plane; at this point provided
by the schistosity. General schistosity of the study
area is very changable. View from the ridge.
Tyrol government, geoinformation)
N
Figure 2: Location map of the study site in the Kauner
Valley (“Kaunertal“), Austria, shown as rectangle in
red.
N
Figure 4: Bulging of the lower parts of the moving mass
what leads to the valley close-up and temporal retention
of the river. Cutout compare with Figure 14. (Reference:
Figure 11: View from the upper part of the Stupfarri
rock slide into the southern Kauner valley. Extensionl
cracks and scarps facing uphill can be seen. They
have a depths up to 8 m.
Figure 3: Orthophoto of the study site. Red: expansion of the mass movement. (Base: tiris, Province of
Tyrol).
LIDAR height model, Tyrol government, geoinformation)
Geology of the Study Site
Figure 12: Geological Map of
the study site with a
hillshade underlayer. For the
legend see the box with the
cross sections. In red the
boundaries of the mass
movement.
The map shows that the
mass movement takes place
within a paragneiss complex
of the Ötztal-StubaiCrystallin. A varying
appearance of the
paragneiss is typical but
mainly it can be described as
a biotite-plagioclase-gneiss.
The variations range
between a mica schist,
quarzite and albit rich schist;
the boundaries are blurred.
This complex is surrounded
by an amphibolite.
On the left side the mass
movement is restricted by a
fault, for these structures
see also Figure 14. In the
area of the mass movement
fil
o
Pr
B
Cross Section
Scale 1:10.000
Cross Section
LEGEND
Geology
Talus Material
Sediments of the Valley
Sediments of the River
Moraine Material
Faults
Fault
Fault, assumed
Paragneiss Formation
Paragneiss, disagreggated
Amphibolite
Quarzite
Eklogite
Structure of Movement
Basic Shear Horizont, assumed
Shear Horizont of Slab, assumed
within displaced masses
Figure 13: Table of geological cross sections. Cross Section B parallel and Cross Section D transversal to the mass
movement. The depth of the mass movment is not confirmed by further investigation such as drillings or geophysical
methods. Because of the geometry of the surface the authors of this study assume a depth of 200 - 300 m. More over the
dashed lines indicate the position of shear bands betweenf slabs of moving mass. The position of the amphibolite in the
transversal Profil D is unclear but it might have an influence on the mechanical processes.
N
N
Kinematical Model
J2
J1
J1
J3
Figure 14: Airborne laser
scanning based digital
elevation model (hillshade)
showing geomorphologic
features of the Stupfarri rock
flow (e.g. different parts of
the sliding mass,
boundaries, uphill facing
scarps, extension cracks).
Reference: LIDAR height
model, Tyrol government,
geoinformation.
Sc
hi
Joint Sets
J1
J2
Figure 17: Block model of joints sets with generalized
surface. Schistosity plane in grey lines, slope plane in
green. No single discontinuity is able to form the plane of
rupture.
Joint Set 1
et 2
Schistosity
Joint S
Slope Direction
Schistosity
Profil B
Profil B
Profil D
Joint Set 1
Joint Set 2
Joint Set 3
225/28
269/31
135/90
038/90
096/51
260/56
334/57
os
ity
Ko1: J1 096/51
Ko2: J2 260/56
Ko3: J3 334/57
Figure 15: Counter Plot of the messured joints of 11 scan lines close to the
mass movement along the ridge. J1 is the dominant Joint Set, this one is
also measured at other mass movements in the region (Zangerl & Prager,
2008).(generated with Dips by RocScience)
st
Figure 18: Schematic sketch showing the possibility of
sliding on the intersection of J1 and the schistosity plane.
Dimensions of the Stupfarri
Landslide
Height of the Landslide
Total Length
Length of displaced mass
H
L
Ld
Lr
1700 m
3700 m
3500 m
3450 m
Depth of displaced Mass
Depth of surface of rupture
Width of displaced mass
Width of surface of rupture
Dd
220 m
Dr
250 m
Wd 1950 m
Wr 1950 m
K3
ACKNOWLEDGMENTS
The authors wish to thank Tiroler Wasserkraft AG (TIWAG), A-6020 Innsbruck, ILF Consulting Engineers Ltd., A-6063 Rum, p+w Baugrund+Wasser GEO-ZT
GmbH, A-6060 Hall, alpECON Wilhelmy KEG, A-6165 Telfes, Kplus-FFG and Tiroler Zukunftsstiftung for supporting this work.
Extension Cracks
Sl
op
e
D
ire
ct
io
N
n
Profil D
Figure 16: Structural Diagrame of the study area. It shows no
parallel structures to the slope.
REFERENCES
Amperer, O., 1939. Über einige Formen der Bergzerreißung. Sitzungsbr. Akad. Wiss. Wien, math.-nat. Kl., Abt. 1, 148, Vienna, 1-14 pp.
Beyer, W.H., 1987. Handbook of Mathematical Sciences. 6th ed., Boca Raton/Florida.
Cruden, D.M. & Varnes, D.J., 1996. Landslide Types and Processes. – In: Turner, A.K. & Schuster, R.L. (ed.), 1996. Landslides. Investigation and Mitigation.
Special Report 247 (National Research Council (U.S.) Transportation Research Board, Washington/D.C.
Hutchinson, J., 1988. Morphological and geotechnical parameters of landslides in relation to geology and hydrology, General Report. Proc. 5th Int. Symp. on
Landslides, 1, 3-35.
Stini, J., 1941. Unsere Täler wachsen zu. Geologie und Bauwesen, 13, Vienna, 71-79 pp.
UNESCO Working Party for World Landslide Inventory, 1993. A Suggested Method for a Landslide Summary. Bull. Int. Assoc. Eng. Geol., 47, 53-47 pp.
Varnes, D., 1978. Slope movements: types and processes. In: Eckel, E., (ed.). Landslides Analysis and Control. Transp. Res. Board, Spec. Rep.,176, 11-33 pp.
Weissflog, M., 2007. Ursachen und Phänomene des Talzuschubs Stupfarri-Kaltenbrunn / Vorderes Kaunertal (Tirol/Österreich). Diploma Thesis, Technische
Universität München, 64 pp.
Zangerl, C., 1997. Kristallingeologische und petrologische Untersuchungen im vorderen Ptiz- und Kaunertal. Diploma Thesis, Universität Innsbruck, Innsbruck.
Zangerl, C. & Prager, C. 2008: Influence of geological structures on failure initiation, internal deformation and kinematics of rock slides. The 42nd U.S. Rock
Mechanics Symposium (USRMS), 29.06.-02.07.2008, San Francisco, CA, American Rock Mechanics Association, paper 08-063, 13 pp.