GPR geophysical method as a remediation tool to determine zones of high penetration resistance of soil

Abstract

Abstract In this study, we demonstrated application of ground penetrating radar towards assessing zones of high penetration resistance (PR) within soil horizons with a view to characterize the subsurface media. Soil attributes changes both in time and space can be difficult to understand. This may be largely due to concealing nature of subsurface media and convectional methods of soil investigations that are usually restricted to observation at the surface and discrete points. Thus making interpolations, inferences and conclusions from such methods inadequate and less reliable. However, ground penetrating radar (GPR) – a geophysical method of investigation was used in this study in lieu of the traditional methods. Soil variability measured in its PR (strength) is related to its compactness-function of bulk density. GPR utilizes electromagnetic (EM) energy in the range of 10 MHz to 3GHz that propagates through the investigative materials. Analysis of the two-way travel time of EM wave gives information about the velocity of the travelling wave. Data were acquired on a loamy silty soil at a farmland in Krakow as a test site simulated with compaction by tractor passes to induce densification of the subsurface layers. Results of the test depicted distinguishing feature of the compacted zones which is reduction in (EM) waveform amplitude and rapid decay of the EM frequency spectra. The research outcome shows swift, cheap and less cumbersome method of soil investigation.