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2015 bgs pre_p_short
- 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
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- 4. P1 P2 (long profile) N6 N4 N2 N0 S2 S4 S6 S8 S10 S12 S14 S16 S18 S20 N Danube N The landslidearea with the measuring profiles
- 5. The directly visible mainfracture (MF) study site Fractures of the Vár Hill ~ 1 m
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- 7. measured quantity penetrationdepth 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 afracture step 1 step 3step 2
- 9. Principle of themeasurement 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 23 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 12.318.3 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 23 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 69 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 hilledge 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 69 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 69 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 - Anew 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 thePre-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 foryour attention! Danube, the guilty