Kvantitativna procjena podložnosti stijenskih kosina odronima integracijom kinematičkih i statističkih analiza

doctoral thesis

• Title: Kvantitativna procjena podložnosti stijenskih kosina odronima integracijom kinematičkih i statističkih analiza : doktorski rad
• Title (english): Quantitative rockfall susceptibility assessment by integrating kinematic and statistical analyses : doctoral dissertation
• Author: Marin Sečanj
• Mentor: Snježana Mihalić Arbanas (mentor)
• Committee member: Martin Krkač (predsjednik povjerenstva)
• Committee member: Anja Vrbaški (član povjerenstva)
• Committee member: Željko Arbanas (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mining, Geology and Petroleum Engineering; Zagreb
• Defense date and country: 2020-11-06, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mining, Petroleum and Geology Engineering; Geological Engineering
• Universal decimal classification (UDC): 55 - Geology. Meteorology. Hydrology

Abstract

U doktorskom radu prikazani su rezultati istraživanja čija je svrha bila razvoj nove metode za kvantitativnu procjenu podložnosti stijenskih kosina odronima u detaljnom mjerilu primjenom daljinskih istraživanja. Metoda je razvijana na četiri pilot područja izgrađenim od karbonatnih i klastičnih naslaga: stijenske kosine iznad grada Omiša, stijenske kosine Brljan u Nacionalnom parku Krka te stijenski zasjeci Špičunak i Lokve u Groskom kotaru. 3D digitalni modeli stijenskih kosina pilot područja, visoke preciznosti i razlučivosti, izrađeni su na osnovi terestričkog laserskog skeniranja i snimanjem iz zraka pomoću bespilotne letjelice. Analizom digitalnih modela pilot područja identificirane su i određene značajke stijenske mase (stupanj trošnosti i vrsta stijene) i geometrijske značajke diskontinuiteta (orijentacija i setovi diskontinuiteta, razmak i postojanost diskontinuiteta) ručnim, polu-automatiziranim i automatiziranim metodama i tehnikama. Na osnovi rezultata analiziranih podataka izdvojene su kvazi-homogene inženjerskogeološke zone koje su zajedno s pripadajućim podacima o značajkama stijenske mase i geometrijskim značajkama diskontinuiteta predstavljale ulazne podatke za procjenu podložnosti stijenskih kosina odronima. Podložnost stijenskih kosina odronima kvantificirana je s obzirom na indeksne pokazatelje podložnosti planarnom, klinastom i slomu prevrtanjem te indeksom podložnosti stijenskih kosina odronima. Navedeni indeksni pokazatelji računati su za svaku ćeliju digitalnih modela istraživanih stijenskih kosina na temelju analiza vjerojatnosti pojave diskontinuiteta ili presječnica diskontinuiteta na određenom dijelu stijenske kosine, prostornih kinematičkih analiza i vrijednosti modificiranog kinematičkog indeksa hazarda. Cijeli proračun u potpunosti je automatiziran pomoću razvijenog algoritma ROCKS. Modeli podložnosti stijenskih kosina odronima za pilot područja izrađeni su interpolacijom vrijednosti indeksnih pokazatelja na digitalnim modelima površina stijenskih kosina. Verifikacijom modela podložnosti utvrđeno je da visoke vrijednosti podložnosti ukazuju na potencijalno nestabilne stijenske blokove, nepovoljno orijentirane diskontinuitete, a zone veće gustoće visokih vrijednosti indeksnih pokazatelja ukazuju na prioritetna područja prilikom ublažavanja hazarda i rizika od odrona. Metoda za kvantitativnu procjenu stijenskih kosina odronima može se primjenjivati u inženjerskogeološkim i geotehničkim istraživanjima stijenskih kosina, u inženjerskim projektima sanacije i zaštite stijenskih kosina te za mjere ublažavanja hazarda i rizika od odrona.

Abstract (english)

The aim of this doctoral dissertation was to develop a method for quantitative rockfall susceptibility assessment at slope scale using techniques of remote sensing. For the development of this method 4 pilot areas were chosen, each with different structural-geological setting. These pilot areas are rock slopes above the town of Omiš, rock slopes and rock cuts Brljan in the Krka National Park, rock cuts Špičunak and Lokve in the Gorski kotar area. High-resolution and precision digital models of the investigated rock slopes were created based on terrestrial laser scanning and UAV based photogrammetry. Identification and mapping of the rock mass properties (degree of weathering and rock type) and the geometrical properties of the discontinuities (orientation and sets, spacing and trace length) was carried out by remote sensing on the digital models using manual, semi-automated and automated techniques and methods. Also, for the Lokve rock cut pilot area two different rock types were determined by semi-automated analysis of intensity data, derived from terrestrial laser scanner. Based on analysed rock mass and discontinuity data, pilot areas were divided into 65 quasi-homogenic engineering geological zones and each zone was associated with certain rock mass and discontinuity data that can be found in that zone. Engineering geological zones, along with rock mass and discontinuity properties, were used as input dana for quantitative rockfall susceptibility assessment. In order to quantify susceptibility, 4 susceptibility indices were developed: Plane Failure, Wedge Failure and Toppling Susceptibility Indices, from which Rockfall Susceptibility Index is derived based on the probability of union. Susceptibility indices were calculated for each 3D rock slope model cell based on the probability analysis, spatial kinematic analysis and modified Kinematic Hazard Index. This calculation processes were entirely automated by developed algorithm ROCKS in MATLAB programming platform. Rockfall susceptibility models were created by interpolation of the susceptibility indices on the digital rock slope models for each pilot area. In total 16 rockfall susceptibility models were created. Verification of the resulting rockfall susceptibility models has indicated that high values of Rockfall Susceptibility Index highlight potentially unstable rock blocks and unfavourably orientated discontinuities. Also, zones with higher density of high Rockfall Susceptibility Index values point out to certain quasi-homogenic engineering geological zones which should be priority in rockfall hazard and risk reduction by efficient design of rock slope protection measures. Developed method for quantitative rockfall susceptibility assessment has shown that it can be used in detailed engineering geological and geotechnical investigation of rock slopes, and rock slope remediation and protection assessments. Also, it represents a precise and valuable input data for rockfall hazard and risk assessment at the slope scale.

• Keywords: odroni; automatizirana procjena podložnosti; modeli podložnosti odronima TLS; UAV; digitalni modeli; stijenska masa; Omiš; Brljan; Lokve; Špičunak
• Keywords (english): rockfall; automated rockfall susceptibility assessment; rock mass; discontinuities; TLS; UAV; rock slope digital models; Omiš; Brljan; Lokve; Špičunak
• Language: croatian
• URN:NBN: urn:nbn:hr:169:461659
• Study programme: Title: Applied Geosciences, Mining and Petroleum Engineering; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor znanosti/doktorica znanosti (doktor znanosti/doktorica znanosti)
• Catalog URL: http://katalog.nsk.hr/F/?func=direct&CON_LNG=ZAG&local_base=ZAG01_WEB&doc_number=000686538
• Type of resource: Text
• Extent: 340 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2022-11-06
• Created on: 2021-01-19 09:29:58