An Integrated Application Ground Penetrating Radar and Seismic Refraction for Non-Intrusive Investigation of Geophysical and Geotechnical Targets

Author(s):  
Kebabonye Laletsang ◽  
Lucky Moffat

This chapter presents a brief synopsis of geophysical exploration methods useful in geotechnical and environmental applications. The treatment is keyed at the baccalaureate level to enable geophysics graduates to apply these methods with minimal supervision. In the seismic method, the background theory is given. Application emphasis is placed on the reversed refraction profile technique which ultimately allows interpretation using the Generalized Reciprocal Method (GRM) first introduced by Palmer in 1986. The latter part of the chapter provides a review of the Ground Penetrating Radar (GPR) method used in high resolution geophysical surveys. This method has recently been used extensively to map defects developed on ageing road and pipeline infrastructure in Botswana. The treatment of theory is restricted again to suit the baccalaureate level of geophysics courses at university and many application examples are given. A discussion on acquisition parameters is included to guide the reader through implementation of the method.

2021 ◽  
Author(s):  
A. Sendrós ◽  
A. Casas ◽  
C. Abancó ◽  
L. Rivero ◽  
R. Garcia-Artigas ◽  
...  

2015 ◽  
Vol 19 (3) ◽  
pp. 1125-1139 ◽  
Author(s):  
P. Klenk ◽  
S. Jaumann ◽  
K. Roth

Abstract. High-resolution time-lapse ground-penetrating radar (GPR) observations of advancing and retreating water tables can yield a wealth of information about near-surface water content dynamics. In this study, we present and analyze a series of imbibition, drainage and infiltration experiments that have been carried out at our artificial ASSESS test site and observed with surface-based GPR. The test site features a complicated but known subsurface architecture constructed with three different kinds of sand. It allows the study of soil water dynamics with GPR under a wide range of different conditions. Here, we assess in particular (i) the feasibility of monitoring the dynamic shape of the capillary fringe reflection and (ii) the relative precision of monitoring soil water dynamics averaged over the whole vertical extent by evaluating the bottom reflection. The phenomenology of the GPR response of a dynamically changing capillary fringe is developed from a soil physical point of view. We then explain experimentally observed phenomena based on numerical simulations of both the water content dynamics and the expected GPR response.


2019 ◽  
Vol 17 (3) ◽  
pp. 291-298
Author(s):  
Niklas Allroggen ◽  
Adam D. Booth ◽  
Sandra E. Baker ◽  
Stephen A. Ellwood ◽  
Jens Tronicke

2018 ◽  
Vol 25 (3) ◽  
pp. 171-195 ◽  
Author(s):  
Immo Trinks ◽  
Alois Hinterleitner ◽  
Wolfgang Neubauer ◽  
Erich Nau ◽  
Klaus Löcker ◽  
...  

Author(s):  
Horst G. Brandes

The effectiveness of electromagnetic (EM), ground penetrating radar (GPR) and seismic refraction (SR) were evaluated by surveying a shallow trench in which a number of objects of varying composition and size were buried. The trench was excavated in granular calcareous fill material. An experienced geophysical contractor was asked to provide blind predictions of object locations using each of the techniques in turn. GPR with a 400 MHz antenna was the most successful, followed by SR and EM surveying. GPR and SR were also carried out at the port of Hilo to investigate complex subsurface conditions.


2020 ◽  
Vol 12 (13) ◽  
pp. 2146
Author(s):  
Eusebio Stucchi ◽  
Adriano Ribolini ◽  
Andrea Tognarelli

We aim at verifying whether the use of high-resolution coherency functionals could improve the signal-to-noise ratio (S/N) of Ground-Penetrating Radar data by introducing a variable and precisely picked velocity field in the migration process. After carrying out tests on synthetic data to schematically simulate the problem, assessing the types of functionals most suitable for GPR data analysis, we estimated a varying velocity field relative to a real dataset. This dataset was acquired in an archaeological area where an excavation after a GPR survey made it possible to define the position, type, and composition of the detected targets. Two functionals, the Complex Matched Coherency Measure and the Complex Matched Analysis, turned out to be effective in computing coherency maps characterized by high-resolution and strong noise rejection, where velocity picking can be done with high precision. By using the 2D velocity field thus obtained, migration algorithms performed better than in the case of constant or 1D velocity field, with satisfactory collapsing of the diffracted events and moving of the reflected energy in the correct position. The varying velocity field was estimated on different lines and used to migrate all the GPR profiles composing the survey covering the entire archaeological area. The time slices built with the migrated profiles resulted in a higher S/N than those obtained from non-migrated or migrated at constant velocity GPR profiles. The improvements are inherent to the resolution, continuity, and energy content of linear reflective areas. On the basis of our experience, we can state that the use of high-resolution coherency functionals leads to migrated GPR profiles with a high-grade of hyperbolas focusing. These profiles favor better imaging of the targets of interest, thereby allowing for a more reliable interpretation.


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