Raziskave dveh zemeljskih plazov na Potoški planini z metodo vertikalnega električnega sondiranja

Zupančič, Lan (author), Gosar, Andrej (mentor)

Pobočni masni premiki so v Sloveniji ena pogostejših naravnih nevarnosti, ki ogrožajo ljudi in infrastrukturo ter zahtevajo določene preventivne ukrepe z namenom preprečitve morebitnih katastrofalnih posledic v primeru njihove sprožitve. Diplomska naloga se osredotoča na pobočne masne premike na območju Potoške planine, natančneje na premike dveh zemeljskih plazov, Urbas in Čikla, ki sta nad Koroško Belo pri Jesenicah. Zemeljska plazova predstavljata potencialno izvorno območje za nastanek drobirskega toka, ki lahko ogrozi Koroško Belo. Da bi bolje spoznali velikost in stanje plazov, so bile izvedene geofizikalne raziskave za projekt, na katerem deluje podjetje Geoinženiring d. o. o. Po predhodnih raziskavah s seizmično refrakcijsko tomografijo in 2D električno tomografijo je bila v tej fazi uporabljena geofizikalna metoda vertikalnega električnega sondiranja, ki ima večji globinski doseg. Na obeh plazovih, Urbas in Čikla je bilo skupaj izmerjenih 12 geoelektričnih sond. Metoda je omogočila natančnejšo določitev debeline gruščev, globine drsnih ploskev in opredelitev globlje ležeče litološke sestave območja. Na podlagi rezultatov predhodnih raziskav, ki so bili podlaga za interpretacijo štirih od 12 geoelektričnih sond za namene diplomske naloge, so bile ugotovljene globina drsne ploskve, debelina gruščev in globlje ležeča litologija za oba plazova. Pri geoelektrični sondi EPP-11 na plazu Čikla sem določil interval globine drsne ploskve od 30 m do 35 m pod površjem in debelino gruščev od 34 m do 39 m. Na plazu Urbas sem na geoelektrični sondi EPP-4, ki je izmerjena na lokaciji geološke vrtine PP-1, določil drsno ploskev na globini 15 m pod površjem in debelino gruščev od 10,5 m do 14,5 m. Pri geoelektrični sondi EPP-7 je drsna ploskev v intervalu od 14 m do 16 m, debelina gruščev pa je od 11,5 m do 13,5 m. Na geoelektrični sondi EPP-8 sem določil interval drsne ploskve od 9 m do 11 m pod površjem in debelino gruščev na 8,5 m. Rezultati geofizikalnih raziskav bodo podlaga za nadaljnjo izvajanje preventivnih ukrepov na območju Potoške planine z namenom zaščite prebivalcev Koroške Bele pred nevarnostjo drobirskega toka.

• Language: Slovenian
• Keywords: pobočni masni premiki, zemeljski plaz, drobirski tok, vertikalno električno sondiranje, Potoška planina, Koroška Bela.
• Work type: Bachelor thesis/paper
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Year: 2018
• PID: 20.500.12556/RUL-103596
• COBISS.SI-ID: 1417822
• Publication date in RUL: 20.09.2018

Secondary language

• Language: English
• Title: Surveys of two landslides on the Potoška planina using vertical electrical sounding

Abstract

Slope mass movements in Slovenia are one of the most frequent natural hazards that threaten people and infrastructure and require certain preventative measures in order to prevent possible catastrophic consequences in the event of their triggering. The bachelor’s thesis focuses on slope mass movements in the area of the Potoška planina, more precisely on the movements of two landslides, Urbas and Čikla, which are located above Koroška Bela near Jesenice. Two landslides represent a potential source area for a debris flow, which can endanger Koroška Bela. For the purpose of better knowledge of the size and condition of the two landslides, geophysical research was carried out by Geoinženiring for a research project. After previous surveys used seismic refraction tomography and 2D electrical tomography, a geophysical method of vertical electrical sounding was used, which has a larger depth penetration. On both landslides, Urbas and Čikla, together, 12 geoelectric soundings were measured. The method has provided data, which allowed the determination of the thickness of gravels, the depth of the shear planes, as well as the definition of the deeper lithological structure of the area. Based on the results of previous research, which served as the basis for the interpretation of four out of 12 geoelectric soundings for the purpose of the bachelor’s thesis, the depth of the shear plane, the thickness of the gravels, and the deeper lithology for both landslides were determined. On the EPP-11 geoelectric sounding on the Čikla landslide, I determined the depth of the shear plane from 30 m to 35 m below the surface and the thickness of the gravels from 34 m to 39 m. On the Urbas landslide, on the geoelectric sounding EPP-4, which was measured at the location of the geological borehole PP-1, I determined the shear plane at a depth of 15 m below the surface and a thickness of gravels from 10.5 m to 14.5 m. In the case of the EPP-7 geoelectric sounding, the shear plane is in the interval from 14 m to 16 m. The thickness of gravels is from 11.5 m to 13.5 m. On the EPP-8 geoelectric sounding, the shear plane ranges from 9 m to 11 m below the surface and the thickness of the gravels up to 8.5 m. The results from geophysical surveys will serve as the basis for the further implementation of preventative measures in the area of Potoška planina for the purpose of protecting the inhabitants

• Keywords: slope mass movements, landslide, debris flow, vertical electrical sounding, Potoška planina, Koroška Bela.