This document describes a study that used physical modeling to analyze creep processes affecting Mount Granieri in southern Italy. Creep tests were performed on rock samples from Mount Granieri to study the effects of sample dimensions, stress levels, and duration of creep. The results were upscaled to model creep at different depths of a potential landslide on Mount Granieri. The study concluded that tertiary creep deformations of Mount Granieri are due to highly altered granite, and that deformations hundreds of meters from the valley are dependent on secondary creep stages. This physical modeling approach can help zonate deep-seated gravitational slope deformations by stress and inform monitoring using timescales of creep.

1. A PHYSICALLY-BASED SCALE APPROACH FOR THE
ANALYSIS OF THE CREEP PROCESS INVOLVING
MT. GRANIERI (SOUTHERN ITALY)
A. Bretschneider1, R. Genevois2, S. Martino3, A. Prestininzi3, G. Verbena4
French Institute of Science and Technologies for Transport, Development and Network – Nantes, France
University of Padua – Department of Geosciences – Padua, Italy
3 Sapienza University of Rome, CERI Research Centre and Dept. of Earth Sciences – Rome, Italy
4 Tecnostudi Ambiente s.r.l. Professional Company – Rome, Italy
1
2

2. OBJECTIVES AND METHODS
Uniaxial creep tests

3. OBJECTIVES AND METHODS
Creep tests on rock samples of Mt. Granieri
- Dimensions (geometrical scaling)
- Stress level
- Duration of the creep process (time scaling)
Real case: DSGSD Mt. Granieri

4. CASE STUDY
1000 m asl
200 m asl

6. Double crest
Trench

7. Fiumara Allaro
Mt. Granieri
WSW
ENE
Metamorphic complex (Schists)
Thermometamorphic contact belt
Granitic complex

8. Mt. Granieri
WSW
Strath terraces correlated to:
- geomorphological data on Serre massif et Aspromonte
- marine terraces
(after Miyauchi et al., 1994)
ENE
III order  ~1000ka
IV order  ~ 950 ka
V order  ~ 900ka
VI order  ~ 400ka
VII order  ~ 300ka

9. CREEP TESTS
Sample
1
2
3
n
(kN/m3)
26.2
26.7
25.6
c
(MPa)
119.2
123.5
66.8
4
(Genevois & Prestininzi, 1979)
25.4
56.5
5
26.1
92.1
(Pa∙s)
Ia (%)
11
13
11
25
10
55
1.7×10
1.4×10
6.3×10
10
44
11
36.9
8.2×10
1.1×10
Ia% = (altered feldspar/total feldspar)*100

10. UPSCALING RATIOS
Dimensions: L* = Lmodel/Lprototype ≠1
Density: * =
model/ prototype
~1
Gravity: g* = gmodel/gprototype =1
Viscosity: * =
model/
prototype
Example of upscaling procedure
- medium alteration level
- specimen length upscaled to 50 m
≠1
Strain rate: ˙* = ˙model/ ˙prototype ≠1
Time : t* = 1/ ˙*
Laboratory
Considering 3 different
geometrical ratios…
5,4 cm
50 m
150 m
300 m
(kg/m3)
g (m/s2)
L (m)
Ratio
2610
2665
0.98
9.81
9.81
1
0.054
50
1.08×10-3
1.06×10-3
(Pa)
.
…and the corresponding stress ratios
Slope
(Pa∙s)
(1/s)
t (s)
1.1×1011
2.68×1021
4.14×10-11
3.91×10-8
2.55×107

11. Ia (%)
t* for 50 m depth t* for 150 m depth t* for 300 m depth
13
3.35×107
1.12×107
5.58×106
25
4.15×107
1.38×107
6.91×106
37
2.55×107
1.72×107
8.60×106
44
6.73×107
2.24×107
1.12×107
55
8.83×107
2.94×107
1.47×107

12. Creep curves for sample 5
(medium alteration)
Three levels of stress
(scaling ratios)

14. CONCLUSIONS
General facts
i.
ii.
This type of analysis can be useful for a zonation of the
DSGSDs (stress criterion)
Can be useful when using monitoring data (time criterion)
Case history facts
iii. Tertiary-creep deformations of Mt. Granieri due to the highly
altered portion of granites
iv. Demostrate that deformations of the portion of the slope
located a few hundred of meters from the valley bottom are
dependent on a secondary creep stage.

15. Thanks for your kind attention
Slide?!?