Numerično modeliranje mehanskih lastnosti diskontinuitet v razpokani in heterogeni kamninski masi : doktorska disertacija

Fabjan, Teja (author), Jovičić, Vojkan (mentor), Forte-Tavčer, Petra (member of the commission for defense), Fifer Bizjak, Karmen (member of the commission for defense), Logar, Janko (member of the commission for defense), Vrabec, Marko (member of the commission for defense)

Iz vidika varne, učinkovite in ekonomsko opravičljive izvedbe geotehničnega objekta, je poznavanje geomehanskih lastnosti kamninske mase ključno. Vendar zaradi aktivne geološke zgodovine, je zgradba kamninske mase pogosto zelo kompleksna in ugotavljanje njenih geomehanskih lastnosti predstavlja med geotehniki vedno znova velik izziv. Postopki za določitev geomehanskih lastnosti kamninske mase, ki se običajno uporabljajo v inţenirski praksi, pogosto poenostavijo realno stanje kamninske mase, kar povzroča posplošene in tudi napačne zaključke. V zadnjem desetletju, vzporedno z razvojem računalniške tehnologije, so numerične metode pokazale velik potencial na področju obravnave problemov v mehaniki kamnin. Doktorska disertacija izkorišča zmogljivosti numeričnih metod za določitev geomehanskih lastnosti razpokane in heterogene kamninske mase, kot je npr. fliš. V diskretnem numeričnem okolju UDEC je bila prvič uporabljena metodologija sintetične kamninske mase (SRM), kjer je obnašanje intaktnih blokov opisano z izotropno-elastičnimi Voronoijevimi elementi, obnašanje na diskontinuitetah pa s Coulombovim rezidualnim modelom razpok. Razvit je bil numerični laboratorij, ki omogoča izvajane simulacij standardnih laboratorijskih preiskav na intaktnem materialu, diskontinuitetah in SRM bloku kamninske mase. Študija parametričnih in občutljivostnih analiz v numeričnem laboratoriju je podala smernice za proces kalibracije intaktnega materiala. Izkazalo se je, da Voronoijev model solidno napove togostne in trdnostne, kot tudi kvalitativne lastnosti intaktne kamnine. Aplikacija SRM metodologije na vzorcu laboratorijskih dimenzij ter na vzorcu večmetrskih dimenzij fliša na območju predora Markovec, je podala moţnost napovedi nelinearne oblike porušne ovojnice, rezidualne lastnosti in anizotropno obnašanje razpokane in heterogene kamninske mase. To je potrdilo zastavljeno tezo disertacije in podalo prednost razvite metodologije pred običajnimi postopki ugotavljanja geomehanskih lastnosti kamninske mase.

• Language: Slovenian
• Keywords: gradbeništvo, disertacije, diskretna numerična metoda, Voronoijevi elementi, kamninska masa, intaktna kamnina, diskontinuitete, mikroparametri, laboratorijske preiskave, UDEC, predor Markovec
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Publisher: [T. Fabjan]
• Year: 2015
• Number of pages: XXX, 248 str.
• PID: 20.500.12556/RUL-71834
• UDC: 519.6:549:550.34.016(497.4)(043.3)
• COBISS.SI-ID: 7104353
• Publication date in RUL: 29.07.2015

FABJAN, Teja, 2015, Numerično modeliranje mehanskih lastnosti diskontinuitet v razpokani in heterogeni kamninski masi : doktorska disertacija [online]. Doctoral dissertation. T. Fabjan. [Accessed 25 March 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=71834

Secondary language

• Language: English
• Title: Numerical modelling of mechanical properties of discontinuities in jointed and heterogeneous rock mass

Abstract

The sufficient knowledge of rock mass properties can ensure that excavation and construction of any geotechnical structure would be safer, time and cost effective. However, rock mass structure is often very complex, because it is a result of diverse geological evolution of a particular region. Therefore, prediction of the rock mass behaviour before the excavation, bound to be addressed with many difficulties. Many different approaches usually used in engineering practice have numerous limitations and its results can lead to incorrect decisions. Due to the rapid development of computer technology, the numerical methods and tools have shown a significant improvement for dealing with problems in rock mechanics and geotechnical engineering. The research presented in this thesis is using the ability of numerical methods for estimation of jointed and heterogeneous rock mass properties, such as flysch. For the first time the synthetic rock mass (SRM) methodology was used in the Universal Distinct Element Code, where intact blocks were simulated by using isotropic-elastic Voronoi elements, and constitutive behaviour of discontinuities was represented by Coulomb residual joint model. The numerical laboratory was developed to simulate the standard laboratory tests on intact rocks, discontinuities and SRM rock mass block. The parametric and sensitivity analysis which was done in numerical laboratory gives guidelines to intact rock calibration procedure. It shows that Voronoi model can give a good prediction of quantitative and qualitative properties of intact rock. An application of SRM methodology on a laboratory-sized and large-scaled SRM model of flysch can predict a non-linear failure envelope, residual and anisotropic behaviour of jointed and heterogeneous rock mass. These results confirm our hypothesis that SRM methodology used in UDEC based on Voronoi model can be used as an advanced tool for predicting the mechanical behaviour of rock masses comparing to approaches commonly used in engineering practice.

• Keywords: civil engineering, thesis, discrete element method, Voronoi tessellation, rock mass, intact rock, discontinuities, microproperties, laboratory tests, UDEC, Markovec tunnel