Karakterizacija inženirsko-geoloških lastnosti fliša z uporabo terestričnega laserskega skeniranja in bližnjeslikovne fotogrametrije : doktorska disertacija

Živec, Tina (author), Verbovšek, Timotej (mentor), Kosmatin Fras, Mojca (co-mentor)

Pri geotehničnem projektiranju objektov v heterogenih hribinah, kot je fliš, je pomembna karakterizacija hribine, s katero opišemo inženirsko-geološke lastnosti na obravnavanem območju. Za karakterizacijo hribine je ključno poznavanje geomehanskih lastnosti intaktne kamnine in diskontinuitet, ki vplivajo na geotehnično obnašanje hribine predvsem v času izkopa, pri heterogenih hribinah pa je pomembno poznavanje tudi deleža posameznih litoloških enot. Za fliš jugozahodne Slovenije in vzhodne Italije je značilno ciklično menjavanje tankoplastnatega laporovca in peščenjaka, ki se pojavljajo v različnih razmerjih in imajo različne geomehanske lastnosti. Debelina plasti je od 2 cm do 60 cm, zato je pri geološki spremljavi izkopa, z ročnim zajemom podatkov, težko ovrednotiti posamezne litološke enote, posebno pri nedostopnih in nestabilnih izdankih ter izkopnih čelih. Posledično so geološki popisi velikokrat pomanjkljivi in subjektivni, kar vpliva tudi na geotehnično projektiranje. V doktorski disertaciji sem se zato usmerila v možnost vključevanja bližnjeslikovne fotogrametrije in terestričnega laserskega skeniranja v geološko spremljavo pri izkopih v tankoplastnatih fliših, saj omogočajo določitev litologije in geometrijskih lastnosti diskontinuitet. Meritve smo izvedli na izbranih lokacijah podzemnih in površinskih izkopov v flišu. Rezultati so pokazali, da sta pri natančnem načrtovanju zajema podatkov bližnjeslikovna fotogrametrija in terestrično lasersko skeniranje primerna pri geološkem popisu tankoplastnatega fliša, pri čemer je priporočljiva kombinacija obeh. Pri karakterizaciji fliša s sistemom inženirsko-geološke klasifikacije RMR, s katerim predvidimo geotehnično obnašanje hribin, predstavljata pomemben doprinos v smeri objektivne inženirsko-geološke spremljave s hitrimi in natančnimi meritvami izdankov in izkopnih čel, saj je projektiranje, ki se navezuje na merjene podatke iz terena je bolj realno od vnaprej določenih analitičnih rešitev.

• Language: Slovenian
• Keywords: fliš, terestrično lasersko skeniranje, bližnjeslikovna fotogrametrija, klasifikacija hribine, intenziteta odboja
• Work type: Dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [T. Živec]
• Year: 2020
• Number of pages: XXXI, 224 str.
• PID: 20.500.12556/RUL-117651
• UDC: 55
• COBISS.SI-ID: 21621763
• Publication date in RUL: 18.07.2020

Secondary language

• Language: English
• Title: Characterisation of engineering geological properties of flysch rock mass by using terrestrial laser scanning and close-range photogrammetry : doctoral dissertation

Abstract

For geotechnical design in heterogeneous rock mass, such as flysch, the rock mass characterisation is important, as it describes engineering geological properties of the investigated area. The knowledge of geomechanical properties of intact rock and discontinuities is crucial for rock mass characterisation, because the geotechnical behaviour of the rock mass during the excavation depends on them. For heterogeneous rock mass characterisation, we need to determine the ratio between different lithological units, as well. Flysch of southwestern Slovenia and east Italy is represented by the cyclic alternation of thin-bedded marlstone and sandstone, with different percentage and different geomechanical properties. Layers are usually 2 cm to 60 cm thick, therefore it is difficult to determine individual lithological units in the field, only using manual data acquisition. This is especially apparent when logging distant and unstable outcrops and excavated faces. As a result, the geological face logs lack of measured data and are subjective. For my doctoral thesis I have therefore decided to test the possibility for integrating close-range photogrammetry and terrestrial laser scanning in the geological logging of excavations in thin-bedded flysch, as it is possible to extract geometrical properties of discontinuities and determine the lithology. Measurements have been performed in selected ground and underground excavations in flysch. The results showed, that in case the data acquisition using close-range photogrammetry and terrestrial laser scanning has been properly planned, it can be appropriate for geological logging of thin-bedded flysch. Due to some limitations, it is advisable to combine both methods. When characterizing flysch by using the RMR classification system, based on which we predict the geotechnical behaviour of the rock mass, the used technologies represent an important contribution towards the objective engineering-geological logging. It is possible to quickly and accurately acquire data of excavated faces. Design relating to measured field data is more realistic than predefined analytical solutions.

• Keywords: flysch, terrestrial laser scanning, close-range photogrammetry, rock mass classification, intensity