Fracture system mapping using Pressure Probe method Szalai, S., Szokoli, K., Metwaly, M., Tóth, Á., Wesztergom, V.

1. Szalai*, S., Szokoli*, K., Metwaly#, M., Tóth $, Á., Wesztergom*, V.
* GGI of the Hungarian Academy of Sciences, Sopron, Hungary, szalai@ggki.hu
# Archaeology department, college of tourism and archaeology, King Saud University, Saudi Arabia
$ Department of Physical and Applied Geology, Eötvös Loránd University, Budapest, Hungary
The 8th Congress of Balkan Geophysical Society, 4–8 October 2015, Chania, Greece
Fracture system mapping using Pressure Probe
method

2. Outlines
Introduction
- Site description
- Measuring method
- Field results
- Verification
Conclusions

3. Study site

4. P1
P2
(long profile)
N6
N4
N2
N0
S2
S4
S6
S8
S10
S12
S14
S16
S18
S20
N
Danube
N
The landslide area with the measuring profiles

5. The directly visible
main fracture (MF)
study
site
Fractures of the Vár Hill
~ 1 m

6. Study site
S10
S8
S6
S4
S10
S8S6
S4
N
2 m
~ 0.5 m

7. measured quantity penetration depth
in cm
maximum
penetration depth
30 cm
probe weight 2.790 g
recommended
drop height is 1m
diameter of the metal rod: 10 mm
scale
Technical specifications of the probe
and execution of the measurement
Cone Penetration Test

8. Exploration of a fracture
step 1
step 3step 2

9. Principle of the measurement
d
3d
-35
-29
-23
-17
-11
-5
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Penetrationdept(cm)
Distance (m)
Pressure Probe result

10. -33
-30
-27
-24
-21
-18
-15
-12
-9
-6
0 1 2 3 4 5 6 7 8 9 10 11 12
Penetrationdepth(cm)
Distance (m)
crew member 1
crew member 2
Danube
MF
Repeability of the PreP measurements

11. -31
-27
-23
-19
-15
-11
-7
0.3 6.3 12.3 18.3 24.3 30.3 36.3 42.3 48.3 54.3 60.3 66.3
Penetrationdeph
(cm)
Distance (m) 3+3+4=10
MF
-31
-27
-23
-19
-15
-11
-7
0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69
Penetrationdepth
(cm)
Distance (m)
-31
-27
-23
-19
-15
-11
-7
0.2 6.2 12.2 18.2 24.2 30.2 36.2 42.2 48.2 54.2 60.2 66.2
Penetrationdepth
(cm)
Distance (m)
5+6+6=17
5+3+6=14
sampling distance: 10cm
sampling distance: 20cm
sampling distance: 30cm
The effect of the sampling distance
Danube

12. -35
-29
-23
-17
-11
-5
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Penetrationdept(cm)
Distance (m)
1 2 3
Danube
profile N4
MF
S8
S12
S16
S20
P1
N6
S4
S6
S10
S18
N4N2
N0
S2
S14
P2
N
Interpreation of the PreP results

13. 4
1b
2a
1a
3d
3c
3b
3a
2b
8a
7
6
5
8b
9
10
I
III
IVa V
VI
VII VIII
II
IXIVb
X
XI
XII
II-III
Penetration
depth (cm)
x (m)
y (m)
MF
II
scarp
PreP map of the study area
Danube
36
30
24
18
12
6
0

14. Danube
-31
-28
-25
-22
-19
-16
-13
-10
-7
0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69
Penetrationdepth(cm)
Distance (m)
MF
S8
S12
S16
S20
P1
N6
S4
S6
S10
S18
N4N2
N0
S2
S14
P2 N
P2 profile PreP result
active sidepassive side

15. River Danube
Vár hill
street
hill edge
Buildings at the bottom of
the Vár hill
S8
S12
S16
S20
P1
N6
S4
S6
S10
S18
N4
N2
N0
S2
S14
P2
MF
1.5-2 m
0.6-1 m
W
E
New mass movement (summer 2015)

16. -31
-28
-25
-22
-19
-16
-13
-10
-7
0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69
Penetrationdepth(cm)
Distance (m)
MF1
Newly developed fractures
MF2
Danube
Verification of the results 1.
P2
S8
S1
2S1
6
S2
0
P1
N
6
S4
S6
S1
0
S1
8
N4
N
2
N0
S2
S1
4
P2 N

17. -31
-28
-25
-22
-19
-16
-13
-10
-7
0 3 6 9 12 15 18 21 24 27 30 33
Penetrationdepth(cm)
Distance (m)
MF
forecasted
and realised
forecasted but
not (yet ?)
realised
???
Verification of the
results 2.
Danube
P1
S8
S1
2S1
6
S2
0
P1
N6
S4
S6
S1
0
S1
8
N4N2
N0
S2
S1
4
P2
N

18. Conclusions 1
- A new method, the Pressure Probe (PreP) method has been
developed which
- is easy to use;
- is cost effective;
- is applicable also in areas which are difficult to reach;
- has very good resolution (2 cm wide fractures are
detectable);
- provides easily interpretable results;
- can e.g. localise fractures very precisely.
Its applicability is limited
if the mechanical properties of the soil are exposed to artificial
changes, e.g. in agricultural areas, or in areas visited by vehicles.

19. Conclusions 2.
Using the Pre-P method the fracture system of a slowly-moving
landslide could have been mapped. It was shown that:
- Even very thin cracks are detectable by this method.
- There are signigficant fractures also in the still passive side
of the landslide; but their distances are about two times
smaller than the distances of the fractures in the active
side of the landslide;
- A well-consolidated zone is attached to the fractures on the
side towards the edge of the hill;
- The southern part of the study area is less endangered than
the northern one.
The Pre-P method enables the delineation of such landslides
and most likely also the prediction of future rupture surfaces.

20. Thank you for your attention!
Danube,
the guilty