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Analysis of GPR Response to Cavities Simulated in the Physical Experiments
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 24th European Meeting of Environmental and Engineering Geophysics, Sep 2018, Volume 2018, p.1 - 5
Abstract
Full-scale physical experiment was conducted to investigate the GPR responses to roadbed cavities using 3-D GPR technique. The experiment employed the testing ground with sandy soil, simulating cavities with dome-shaped structure attributed to old damaged underground facilities such as water supply and sewer pipes made of cast-iron and hume concrete, respectively. The surface of the testing ground was not paved with asphalt concrete at the current stage of the experiments. The GPR responses were investigated using 2-D profile and 3-D volume data obtained with 250 MHz antennas, and with HH and VV antenna orientations. The results of the experiment have shown that the simulated cavities responded with typical hyperbolic shapes reflected from the isolated reflector sources in 2-D and 3-D perspectives. The different antenna orientations have shown the different areal extents of the hyperbolic reflections patterns from the cavities. 3-D GPR volume data has provided better information on the locations and shapes of the cavities in 3-D space. This study is an ongoing project of KIGAM at a second stage of the experiments. More realistic conditions of the road surface with asphalt pavement would be prepared in the testing ground for the next stage of the experiments.