USING GROUND PENETRATING RADAR TO DETERMINE THE TUNNEL LOCATION BURIED UNDER THE GLACIER

• Main Authors: Deryuga Andrey Mikhaylovich, Nabokin Andrey Vladimirovich
• Format: Article
• Language: English
• Published: Moscow State University of Civil Engineering (MGSU) 2013-09-01
• Series: Stroitel’stvo: Nauka i Obrazovanie
• Subjects: ground penetrating radar; location; tunnel; georadar; glacier surge; radargram; ice-saturated soil; the Republic of North Ossetia — Alania; Genaldon
• Online Access: http://nso-journal.ru/public/journals/1/issues/2.pdf

The works were carried out with the help of ground penetrating radar “Grot-10”. Doublet broadband antennas with the central frequency of 100 MHz were used. Georadar measures the speed of EM waves v in ice-saturated soil and then the value ε′ is calculated. The radargrams received as a result of georadar survey, which represents stacked data (the two-way time is indicated on vertical scale), were transformed into depth sections, which reflect the space structure located below ground. The distance between the bottom landing and buried mountain road near the north tunnel portal is 78,5 m (profile # 1), and the distance from the upper landing is 84,5 m (profile no. 2). Later, in the April 2003 during the hole boring with the diameter 1,2 m the vertical distance between the upper landing, where ground penetrating works were carried out, and the carpet road of the tunnel was calculated. This distance appeared to be 83 m, that means, the discrepancy between boring and georadar data (84,5 m) was only 1,5 m. Thus, the results of ground penetrating investigations helped the workers of glacier to make the correct conclusion on time about the location and burial depth of the tunnel.