scholarly journals Combination of ground penetrating radar and seismic surveys of the tailings dam

2021 ◽  
Vol 938 (1) ◽  
pp. 012020
Author(s):  
A Kalashnik ◽  
A Dyakov
Keyword(s):  
Internal Structure ◽  
Ground Penetrating Radar ◽  
Water Saturation ◽  
The Body ◽  
Tailings Dam ◽  
Geophysical Surveys ◽  
In Situ Experiments ◽  
Water Saturated ◽  
Ground Penetrating

Abstract Identification of water-saturated zones in the tailings dams is an actual scientific and practical task in terms of providing, first of all, their mechanical strength and filtration stability. Use of active sounding geophysical study methods allows obtaining sufficiently detailed information about the peculiarities of the internal structure of the tailings dam and the degree of water saturation of the composing soils. The paper presents the results of in-situ experiments on the study of the tailings dam of the mining enterprise by ground penetrating radar (GPR) and seismic methods. A comparative analysis of the conducted studies has allowed clarifying the internal structure and assessing the dam’s condition, paying special attention to the identification of local zones of increased water saturation and filtration. Based on the calculated correlation coefficient of electromagnetic and seismic wave velocity values, it was revealed that synchronization of geophysical surveys allows significantly increasing the reliability of in-situ determinations, as well as obtaining more reliable data. The results of the studies are the basis for predicting the most vulnerable places (zones) of a bulk ground hydraulic facility, as well as the localization of water-saturated areas in the body of the ground structures with greater reliability and performance.

INTEGRATING OF GEORADAR ANS SEISMIC STUDIES OF THE TAILINGS DAM

2021 ◽  
Author(s):  
Alexander Dyakov ◽  
A. Kalashnik
Keyword(s):  
Internal Structure ◽  
Water Saturation ◽  
The Body ◽  
Tailings Dam ◽  
Hydraulic Facility ◽  
Tailings Dams ◽  
Geophysical Surveys ◽  
In Situ Experiments ◽  
Water Saturated

Identification of water-saturated zones in the tailings dams is an actual scientific and practical task in terms of providing, first of all, their mechanical strength and filtration stability. The prevention of accidents in tailings is complicated by the circumstance that the processes of increased filtration, appearing and developing in the dam body, are not fixed on the initial stages by visual and traditional methods. Insufficiency, from the point of view of data completeness, of networks of piezometric boreholes on tailings dams does not allow solving the tasks of necessary information hydrological support. At the same time, the use of active- sounding geophysical study methods allows obtaining sufficiently detailed information about the peculiarities of the internal structure of the tailings dam and the degree of water saturation of the composing soils. A reasoned choice of geophysical methods, as well as their combination, allows increasing the level and reliability of obtained data at subsurface studies. The paper presents the results of in-situ experiments on the study of the tailings dam of the mining enterprise by different in nature wave GPR (georadar) and seismic methods. A comparative analysis of the conducted studies has allowed clarifying the internal structure and assessing the dam’s condition, paying special attention to the identification of local zones of increased water saturation and filtration. Based on the calculated correlation coefficient of electromagnetic and seismic wave velocity values, it was revealed that synchronization of geophysical surveys allows significantly increasing the reliability of in-situ determinations, as well as obtaining more reliable data. The results of the studies are the basis for predicting the most vulnerable places (zones) of a bulk ground hydraulic facility, as well as the localization of water-saturated areas in the body of the ground structures with greater reliability and performance.

scholarly journals Accounting for Surface Roughness Scattering in the Characterization of Forest Litter with Ground-Penetrating Radar

2019 ◽  
Vol 11 (7) ◽  
pp. 828
Author(s):  
Frédéric André ◽  
François Jonard ◽  
Mathieu Jonard ◽  
Harry Vereecken ◽  
Sébastien Lambot
Keyword(s):  
Surface Roughness ◽  
Ground Penetrating Radar ◽  
Land Surface ◽  
Forest Litter ◽  
Relative Dielectric Permittivity ◽  
In Situ Experiment ◽  
In Situ Experiments ◽  
Ground Penetrating

Accurate characterization of forest litter is of high interest for land surface modeling and for interpreting remote sensing observations over forested areas. Due to the large spatial heterogeneity of forest litter, scattering from litter layers has to be considered when sensed using microwave techniques. Here, we apply a full-waveform radar model combined with a surface roughness model to ultrawideband ground-penetrating radar (GPR) data acquired above forest litter during controlled and in situ experiments. For both experiments, the proposed modeling approach successfully described the radar data, with improvements compared to a previous study in which roughness was not directly accounted for. Inversion of the GPR data also provided reliable estimates of the relative dielectric permittivity of the recently fallen litter (OL layer) and of the fragmented litter in partial decomposition (OF layer) with, respectively, averaged values of 1.35 and 3.8 for the controlled experiment and of 3.9 and 7.5 for the in situ experiment. These results show the promising potentialities of GPR for efficient and non-invasive characterization of forest organic layers.

scholarly journals Wet subglacial bedforms of the NE Greenland Ice Stream shear margins

2019 ◽  
Vol 60 (80) ◽  
pp. 91-99 ◽  
Author(s):  
Kiya L. Riverman ◽  
Sridhar Anandakrishnan ◽  
Richard B. Alley ◽  
Nicholas Holschuh ◽  
Christine F. Dow ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Acoustic Impedance ◽  
Impedance Analysis ◽  
Flow Conditions ◽  
Lateral Shear ◽  
Ice Flow ◽  
Ice Stream ◽  
Water Saturated ◽  
Ground Penetrating

AbstractWe describe elongate, wet, subglacial bedforms in the shear margins of the NE Greenland Ice Stream and place some constraints on their formation. Lateral shear margin moraines have been observed across the previously glaciated landscape, but little is known about the ice-flow conditions necessary to form these bedforms. Here we describe in situ sediment bedforms under the NE Greenland Ice Stream shear margins that are observed in active-source seismic and ground-penetrating radar surveys. We find bedforms in the shear margins that are ~500 m wide, ~50 m tall, and elongated nearly parallel to ice-flow, including what we believe to be the first subglacial observation of a shear margin moraine. Acoustic impedance analysis of the bedforms shows that they are composed of unconsolidated, deformable, water-saturated till. We use these geophysical observations to place constraints on the possible formation mechanism of these subglacial features.

Preliminary use of ground-penetrating radar and electrical resistivity tomography to study tree roots in pine forests and poplar plantations

2008 ◽  
Vol 35 (10) ◽  
pp. 1047 ◽  
Author(s):  
Terenzio Zenone ◽  
Gianfranco Morelli ◽  
Maurizio Teobaldelli ◽  
Federico Fischanger ◽  
Marco Matteucci ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Ground Penetrating Radar ◽  
Electrical Resistivity Tomography ◽  
Water Saturation ◽  
Three Dimensional ◽  
Tree Roots ◽  
Resistivity Tomography ◽  
Shape Distribution ◽  
Geophysical Surveys ◽  
Ground Penetrating

In this study, we assess the possibility of using ground penetrating radar (GPR) and electrical resistivity tomography (ERT) as indirect non-destructive techniques for root detection. Two experimental sites were investigated: a poplar plantation [mean height of plants 25.7 m, diameter at breast height (dbh) 33 cm] and a pinewood forest mainly composed of Pinus pinea L. and Pinus pinaster Ait. (mean height 17 m, dbh 29 cm). GPR measures were taken using antennas of 900 and 1500 MHz applied in square and circular grids. ERT was previously tested along 2-D lines, compared with GPR sections and direct observation of the roots, and then using a complete 3-D acquisition technique. Three-dimensional reconstructions using grids of electrodes centred and evenly spaced around the tree were used in all cases (poplar and pine), and repeated in different periods in the pine forest (April, June and September) to investigate the influence of water saturation on the results obtainable. The investigated roots systems were entirely excavated using AIR-SPADE Series 2000. In order to acquire morphological information on the root system, to be compared with the GPR and ERT, poplar and pine roots were scanned using a portable on ground scanning LIDAR. In test sections analysed around the poplar trees, GPR with a high frequency antenna proved to be able to detect roots with very small diameters and different angles, with the geometry of survey lines ruling the intensity of individual reflectors. The comparison between 3-D images of the extracted roots obtained with a laser scan data point cloud and the GPR profile proved the potential of high density 3-D GPR in mapping the entire system in unsaturated soil, with a preference for sandy and silty terrain, with problems arising when clay is predominant. Clutter produced by gravel and pebbles, mixed with the presence of roots, can also be sources of noise for the GPR signals. The work performed on the pine trees shows that the shape, distribution and volume of roots system, can be coupled to the 3-D electrical resistivity variation of the soil model map. Geophysical surveys can be a useful approach to root investigation in describing both the shape and behaviour of the roots in the subsoil.

Interpreting the South Flats Earthwork (20MU2): Insights Gained from Geophysical Surveys

2013 ◽  
Vol 41 (3) ◽  
pp. 261-288 ◽  
Author(s):  
DONALD GAFF ◽  
LAURA SHERROD ◽  
JANET G. BRASHLER
Keyword(s):  
Remote Sensing ◽  
Internal Structure ◽  
Ground Penetrating Radar ◽  
Archaeological Site ◽  
Archaeological Sites ◽  
Small Scale ◽  
The South ◽  
Food Exchange ◽  
Geophysical Surveys ◽  
Ground Penetrating

ABSTRACT Michigan's prehistoric earthen enclosures are among the least understood archaeological sites in the state. This paper explores the function of the South Flats Earthwork (20MU2) using remote sensing strategies to reveal aspects of its internal structure not available through excavation. Ground penetrating radar and magnetometry were employed to explore this fragile archaeological site. Results, coupled with excavation data, suggest that South Flats was the work of a small-scale society and a locus of storage and food exchange through kin ties.

scholarly journals Identifying Spatial and Temporal Variations in Concrete Bridges with Ground Penetrating Radar Attributes

2021 ◽  
Vol 13 (9) ◽  
pp. 1846
Author(s):  
Vivek Kumar ◽  
Isabel M. Morris ◽  
Santiago A. Lopez ◽  
Branko Glisic
Keyword(s):  
Compressive Strength ◽  
Ground Penetrating Radar ◽  
Material Properties ◽  
Temporal Variations ◽  
Concrete Bridges ◽  
Spatial And Temporal Variation ◽  
Reflected Waves ◽  
Ground Penetrating ◽  
Over Time

Estimating variations in material properties over space and time is essential for the purposes of structural health monitoring (SHM), mandated inspection, and insurance of civil infrastructure. Properties such as compressive strength evolve over time and are reflective of the overall condition of the aging infrastructure. Concrete structures pose an additional challenge due to the inherent spatial variability of material properties over large length scales. In recent years, nondestructive approaches such as rebound hammer and ultrasonic velocity have been used to determine the in situ material properties of concrete with a focus on the compressive strength. However, these methods require personnel expertise, careful data collection, and high investment. This paper presents a novel approach using ground penetrating radar (GPR) to estimate the variability of in situ material properties over time and space for assessment of concrete bridges. The results show that attributes (or features) of the GPR data such as raw average amplitudes can be used to identify differences in compressive strength across the deck of a concrete bridge. Attributes such as instantaneous amplitudes and intensity of reflected waves are useful in predicting the material properties such as compressive strength, porosity, and density. For compressive strength, one alternative approach of the Maturity Index (MI) was used to estimate the present values and compare with GPR estimated values. The results show that GPR attributes could be successfully used for identifying spatial and temporal variation of concrete properties. Finally, discussions are presented regarding their suitability and limitations for field applications.

Imaging the internal structure of trunks via multiscale phase inversion of ground-penetrating radar data

2021 ◽  
pp. 1-53
Author(s):  
Lei Fu ◽  
Lanbo Liu
Keyword(s):  
Dielectric Constant ◽  
Internal Structure ◽  
Ground Penetrating Radar ◽  
Phase Inversion ◽  
Multiscale Approach ◽  
White Oak ◽  
Near Surface ◽  
Oak Tree ◽  
Ground Penetrating ◽  
Constant Distribution

Ground-penetrating radar (GPR) is a geophysical technique widely used in near-surface non-invasive detecting. It has the ability to obtaining a high-resolution internal structure of living trunks. Full wave inversion (FWI) has been widely used to reconstruct the dielectric constant and conductivity distribution for cross-well application. However, in some cases, the amplitude information is not reliable due to the antenna coupling, radiation pattern and other effects. We present a multiscale phase inversion (MPI) method, which largely matches the phase information by normalizing the magnitude spectrum; in addition, a natural multiscale approach by integrating the input data with different times is implemented to partly mitigate the local minimal problem. Two synthetic GPR datasets generated from a healthy oak tree trunk and from a decayed trunk are tested by MPI and FWI. Field GPR dataset consisting of 30 common shot GPR data are acquired on a standing white oak tree (Quercus alba); the MPI and FWI methods are used to reconstruct the dielectric constant distribution of the tree cross-section. Results indicate that MPI has more tolerance to the starting model, noise level and source wavelet. It can provide a more accurate image of the dielectric constant distribution compared to the conventional FWI.

Bone permittivity and its effect on using ground-penetrating radar

Geophysics ◽  
2018 ◽  
Vol 83 (1) ◽  
pp. H1-H11
Author(s):  
Blair B. Schneider ◽  
Georgios Tsoflias ◽  
Don W. Steeples ◽  
Rolfe Mandel ◽  
Jack Hofman
Keyword(s):  
Dielectric Properties ◽  
Dielectric Property ◽  
Ground Penetrating Radar ◽  
Relative Permittivity ◽  
Water Saturation ◽  
Mixing Models ◽  
Bone Properties ◽  
Animal Bone ◽  
Bone Minerals ◽  
Ground Penetrating

Ground-penetrating radar (GPR) is a powerful tool that is still being developed for archaeological investigations. We investigated the dielectric properties of mammoth bone and bone from modern bison, cow, deer, and elk as a proxy for applying GPR for detecting prehistoric animal remains. Sample dielectric properties (relative permittivity, loss factor, and loss-tangent values) were measured with an impedance analyzer over frequencies ranging from 10 MHz to 1 GHz. Bone-sample porosity, bulk density, water saturation, and volumetric water content of the specimens were also measured. The measured sample-relative permittivity values were then compared with modeled relative permittivity values using common dielectric-mixing models to determine which parameters control the best-fit predictions of relative permittivity of animal bone. We observe statistically significant dielectric-property differences among different animal fauna, as well as variation as a function of frequency. In addition, we determine that the relative permittivity values of 8–9 for similar minerals, such as apatite, are not suitable as a proxy for predicting animal bone properties. We estimate new relative permittivity values of 3–5 for dry animal bone minerals in the frequency range of 100–1000 MHz using these common dielectric-mixing models. We postulate that differences in bone microstructure contribute to dielectric-property variability.

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