Georadarske meritve v predorih 2. tira Divača-Koper : magistrsko delo

Lotrič, Gregor (author), Vižintin, Goran (mentor), Vukadin, Vladimir (comentor), Šporin, Jurij (member of the commission for defense), Vukelič, Željko (member of the commission for defense)

V magistrski nalogi sem raziskoval kraške razmere vzdolž trase predorov T1 (Lokev) in T2 (Beka) na 2. tiru Divača–Koper. Pri tem sem sodeloval pri izvedbi georadarskih meritev v vrtinah in se seznanil z izzivi, ki jih prinaša delo v zahtevnih gradbenih in kraških razmerah. Glavni cilj naloge je bil ovrednotiti uporabnost metode georadarja v eni sami vrtini pri prepoznavanju kraških pojavov ter ugotoviti, kako se lahko rezultati dopolnjujejo s podatki talnega georadarja, ki so bili ključni pri prepoznavanju in lokaliziranju anomalij pod tlemi predorov. Pri raziskavi sem sodeloval pri meritvah, opravljenih z antenami različnih frekvenc, kar je omogočilo doseganje večje globinske penetracije in natančnejše ločljivosti. Moja naloga je bila predvsem podpora pri izvajanju meritev in osnovni pregled podatkov, obdelanih v programu ReflexW, pri čemer sem pridobil vpogled v postopke obdelave in primerjave s geološkimi podatki. S tem sem prispeval k preverjanju interpretacij in k večji zanesljivosti rezultatov. Ugotovil sem, da je metoda georadarja v vrtini učinkovita pri zaznavanju kraških votlin, con razpokanosti ter sprememb v litološki sestavi. Kljub temu sem se soočil tudi z omejitvami, predvsem zaradi vpliva glinenih mineralov, povečane vsebnosti vlage in višje električne prevodnosti kamnin, ki zmanjšujejo globinski doseg signala. Pomanjkljivost pri meritvah v samo eni vrtini se pokaže pri določanju razsežnosti in lociranju anomalij, saj bi za umestitev v ravnini ali v prostoru potrebovali tri oziroma štiri vrtine. Vendar je prav kombinacija podatkov iz georadarja v vrtini in talnega georadarja pokazala, da lahko združevanje različnih pristopov bistveno izboljša razumevanje kraških razmer. Rezultati moje raziskovalne naloge imajo praktičen pomen za inženirsko prakso, saj omogočajo zgodnje prepoznavanje potencialno nevarnih pojavov in zmanjševanje tveganj pri gradnji predorov.

• Language: Slovenian
• Keywords: Georadar v vrtini, talni georadar, 2. tir Divača-Koper, geotehnologija, geofizika
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Place of publishing: Ljubljana
• Publisher: G. Lotrič
• Year: 2025
• Number of pages: XX, 92 f., 2 f., pril.
• PID: 20.500.12556/RUL-175958
• UDC: 550.3
• COBISS.SI-ID: 257914371
• Publication date in RUL: 14.11.2025

Secondary language

• Language: English
• Title: Georadar measurments in 2nd railway track Divača-Koper tunnels : master's thesis

Abstract

In this master’s thesis, I investigated karst conditions along the route of tunnels T1 (Lokev) and T2 (Beka) on the 2nd railways track Divača–Koper. I actively participated in the borehole ground-penetrating radar (GPR) measurements and became familiar with the challenges of working in demanding construction and karst environments. The main objective of the thesis was to evaluate the applicability of borehole GPR conducted in a single borehole for the detection of karst features and to determine how these results could be complemented by surface GPR data, which were crucial for recognizing and localizing anomalies beneath the tunnel floor. I took part in measurements performed with antennas of different frequencies, which enabled both greater penetration depth and higher resolution. My contribution was mainly in supporting the field surveys and carrying out the initial review of data processed in the ReflexW software, which provided me with insight into the processing procedures and their comparison with geological data. In this way, I contributed to the verification of interpretations and to improving the reliability of results. I found that borehole GPR is effective in detecting karst cavities, fracture zones, and lithological changes. Nevertheless, I also encountered limitations, primarily due to the influence of clay minerals, increased moisture content, and higher electrical conductivity of rocks, which reduce signal penetration depth. A further limitation of conducting measurements in only one borehole lies in the difficulty of determining the extent and precise location of anomalies, since three or four boreholes would be required to reliably define their position in plane or space. However, the combination of borehole and surface GPR data demonstrated that integrating different approaches can significantly improve the understanding of karst conditions. The results of my research have practical value for engineering practice, as they enable early detection of potentially hazardous features and the reduction of risks during tunnel construction.

• Keywords: Borehole Radar Technology, Ground Penetrating Radar, 2nd Railway Track Divača-Koper, Geotechnology, Geophysics.