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1

Near-surface geophysical characterization of gully erosion hazard-prone area in Calabar, southern Nigeria

Ebong Ebong Dickson, Urang Job Gideon, Melouah Oualid, Ugi Anthony Ukpongnukpon, Sule Andebutop

Acta Geophysica

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2024

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Vol. 72, no. 1

85--96

EN

The electrical resistivity, i.e. electrical resistivity tomography (ERT) and direct current-resistivity sounding (DC-ERS), and ground penetrating radar (GPR) methods were deployed to assess a gully erosion site in Bacoco area of Calabar, Nigeria. The study aims to assess the mechanism and dynamics of the gully erosion conditions in the area based on shallow lithostrati-graphic evaluations. The results revealed good contrast in the operative properties (i.e. electrical resistivity and dielectric permittivity) between competent and weak zones along the profiles close to the gully head. The joint interpretations provided reliable shallow subsurface models and lithologies that consist predominantly of lateritic top cover and sands. However, the ERT model delineates the contrast between lithologies and demarcates the weak zones from the relatively competent zones, in contrast to the responses generated by the GPR technique. This joint interpretation approach minimizes the uncertainty due to the non-uniqueness problems common to the geophysical technique. Also, the geophysical interpretations were constrained using lithologic information from the gully walls and one-dimensional (1-D) DC-ERS inverted model to provide additional validity. Our findings suggest the influence of structural control on gully formation and demonstrate its contribution to the complex interactions with other drivers, such as seepages through porous media and high-energy runoff due to intense rainfall. The rapid, non-invasive and environmentally friendly characteristics of ERT and GPR techniques favour their applicability in assessing shallow subsurface environmental problems.

2

Practice of geo-radar research in the Republic of Kazakhstan

Burtyl Yuri, Kapski Denis, Czerepicki Andrzej

Prace Naukowe Politechniki Warszawskiej. Transport

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2023

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z. 136

61--69

EN

The article considers the issues of applying ground penetrating radar (GPR) technologies for engineering purposes concerning subsurface research. It describes the field of application of GPR research during road construction and operation and the advantages and disadvantages of this type of engineering survey. It presents comparative data on the accuracy (inaccuracy) of existing GPR control methods applied to determine the thickness of the monolithic pavement layers in Europe, CIS, and the USA. The main provisions of the GPR survey procedure are described, including four main stages: the analysis of initial materials of surveyed section and equipment preparation; GPR survey; geological verification; processing and interpreting of radargrams; and the preparation of a report. Geophysical works were performed using the geo-radar of the OKO series as part of the road measuring complex DVK-05 on the section of the Astana-Petropavlovsk A-1 highway with cement concrete pavement and on the section of the R-12 "Kokshetau - Atbasar" with asphalt pavement. The example of a radargram and the core sample of a cement concrete pavement taken during geological verification of the thickness of a monolithic layer is presented. Graphs of variation in the thickness of pavement layers by radargrams of longitudinal passages in the indicated road sections with the assumptions about the nature of the heterogeneity of the obtained values are given. The obtained results on the thickness of monolithic layers (cement concrete and asphalt concrete) were assessed on the criteria of quantitative deviation from the required standard value. Recommendations were provided to address positive deviations in the thickness of monolithic pavement layers at various stages of the road survey.

3

The Workflow of Ground Penetrating Radar Data Analysis Based on Maximum Energy Difference Steering

Dang Duy Hoang, Le Cuong Van Anh, Nguyen Thuan Van, Nguyen Long Quoc, Huynh Nhan Thanh

Inżynieria Mineralna

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2023

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no. 1

195--202

EN

Ground Penetrating Radar is commonly used in civil engineering sectors. Underground anomalies (i.e., electric wires, water pipes or sinkholes) can be detected through representations of hyperbolae in the measured processed GPR image. Our work focuses on detecting the underground objects and understanding their metallic or nonmetallic characteristics. The max energy difference attribute is applied to illuminate their positions while phase analysis process can determine change of phase spectrum in the diffracted signals. For improving phase analysis, we applied a novel workflow combining conventional processed steps and a zooming step for preserving phase originality without disturbed by any unnecessary filters. We applied the workflow in model and real data for proving its effectiveness. Interpretation of two real datasets in Vietnam by our workflow can express existences of the artificial underground anomalies as well as their matter characteristics comparing to their surrounding environments.

PL

Ground Penetrating Radar jest powszechnie stosowany w inżynierii lądowej i wodnej. Podziemne anomalie (np. przewody elektryczne, rury wodociągowe lub zapadliska) można wykryć za pomocą reprezentacji hiperbol w zmierzonym przetworzonym obrazie GPR. Nasza praca koncentruje się na wykrywaniu podziemnych obiektów i zrozumieniu ich metalicznych lub niemetalicznych wła-ściwości. Atrybut maksymalnej różnicy energii jest stosowany do oświetlania ich pozycji, podczas gdy proces analizy fazowej może określić zmianę widma fazowego w dyfrakcyjnych sygnałach. Aby usprawnić analizę fazową, zastosowaliśmy nowatorski przepływ pracy łączący konwencjonalne kroki przetwarzania i krok powiększania w celu zachowania oryginalności fazy bez zakłócania przez niepotrzebne filtry. Zastosowaliśmy przepływ pracy w modelu i rzeczywistych danych, aby udowodnić jego skuteczność. Interpretacja dwóch rzeczywistych zbiorów danych w Wietnamie za pomocą naszego przepływu pracy może wyrazić istnienie sztucznych anomalii podziemnych, a także ich charakterystykę materii w porównaniu z otaczającym je środowiskiem.

4

Skanowanie konstrukcji, wykorzystanie metody prądów wirowych i georadarowej do celów lokalizacji i detekcji zbrojenia

Giryn Stefan

Przegląd Budowlany

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2021

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R. 92, nr 10

54--57

PL

Artykuł przedstawia zyskujące w ostatnim czasie na popularności i znaczeniu elektromagnetyczne metody nieniszczące badań (skanowania konstrukcji), indukcję elektromagnetyczną zwaną też metodą prądów wirowych (Eddy Current) i metodę georadarową (GPR). Przybliżono ich zasadę działania, możliwości i ograniczenia, a przede wszystkim porównano uzyskane nimi wyniki na podstawie przeprowadzonych przez autora skanowań.

EN

Article presents the recently gaining popularity and importance electromagnetic nondestructive concrete scanning methods, electromagnetic induction (also known as eddy current or Foucault’s currents) and ground penetrating radar (GPR). It discusses their principle of operation, possibilities and limitations, and above all compares the obtained results based on the scans performed by the author.

5

Unmanned ground vehicle equipped with ground penetrating radar for improvised explosives detection

Szynkarczyk Piotr, Wrona Józef, Pasternak Mateusz, Rubiec Arkadiusz, Serafin Piotr

Journal of Automation Mobile Robotics and Intelligent Systems

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2021

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Vol. 15, No. 2

20--31

EN

The article presents some objectives and results of the European Defense Agency Program on: Improvised Explosive Devices Detection (IEDDET Program). The goal of the article is to describe the work, results and recommendations regarding Unmanned Ground Vehicle (UGV) and Ground Penetrating Radar (GPR) - contributions within the MUSICODE project. Its scope and goals were presented, which are in line with the objectives of the IEDDET Program taking into consideration that the recommendations (for UGV and GPR) are related to the goals, not the results of MUSICODE project. There were described scenarios and the resulting changes in the structure implemented in the UGV - the FLORIAN robot which served as a sensors carrier including Ground Penetrating Radar (GPR). The main focus of the article is to find the answer to the research question: what is an impact of using the GPR to be mounted on the UGV to detect improvised explosive devices (IEDs) on the UGV construction and the GPR results. The structure of this radar was described and examples of tests results were presented. The summary presents recommendations for the construction of an unmanned land platform to carry sensors used in the work carried out in the MUSICODE project and conclusions regarding GPR, resulting from the experiences gained under the IEDDET Program.

6

A Review on Impulse RADAR

Kumar Saket, Kumar Amit, Singh Vikrant, Singh Abhishek Kumar

International Journal of Electronics and Telecommunications

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2021

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Vol. 67, No. 4

579--587

EN

RADAR plays a vital role in military applications since its origin in the 2nd world war. Recently it has been used in surface inception, health monitoring, infrastructure health monitoring, etc. In these applications, Ultra-wideband RADAR systems are more popular than traditional RADAR systems. Impulse RADAR is a special kind of ultra-wideband RADAR, which is mostly used for surface penetration, through-wall imaging, antimissile detection, anti-stealth technology, etc. because of its high resolution and low center frequency. Out of all these applications, impulse RADAR has been used intensively as a ground-penetrating RADAR for the detection of land mines, underlying pipelines, buried objects, etc. This report has attempted to provide the steps for designing the impulse ground penetrating RADAR (GPR) as well as provides the value of crucial parameters required in the design process of commercial GPR systems.

7

Analyzing the behavior of GPR wave propagation in zinc contaminated soil combining the dielectric properties-experimental study

Liu Zonghui, Li Jiaqi, Liu Yitian, Liu Chenhui, Li Chuanghui, Zhou Dong

Acta Geophysica

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2021

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Vol. 69, no. 2

483--495

EN

There is a very strong link between the behavior of ground penetrating radar (GPR) wave propagation in zinc-contaminated soil and the dielectric properties of soil. This relationship can be of signifcant use in the practices of quick detecting the degree of pollution in zinc-contaminated soil. In this research, measurements were conducted on the zinc-contaminated soil samples with diferent soil index properties (i.e., zinc ion concentration, wet density and moisture content). The radar refection wave data of the common midpoint and common-ofset sounding mode were obtained by using the 600 MHz antenna, and the relative permittivity was measured using the vector network analyzer. The attribute analysis of radar refection wave shows that the wave velocity is afected by wet density and moisture content, but independent of zinc ion concentration. Both the amplitude and the peak frequency decrease with the increase in zinc ion concentration, wet density and moisture content. For the soil dielectric properties, the metal ions can change the conductivity of solution in soil, afecting the imaginary part of relative permittivity, but with little efect on the real part. The positive correlations between the relative permittivity with density and moisture content are caused by the variation of three-phase composition of soil. Besides, the measured soil dielectric properties and the radar refected wave attributes confrm each other, which can well explain the change rules of electromagnetic wave velocity, amplitude and central frequency. The presented results can increase understanding and confdence on GPR for quantitative monitoring and detecting of zinc-contaminated soil.

8

Wykorzystanie metody konduktometrycznej i georadarowej do identyfikacji stopnia ugniecenia wierzchniej warstwy gruntu

Akinsunmade Akinniyi, Tomecka-Suchoń Sylwia, Pysz Paweł, Karczewski Jacek, Juliszewski Tadeusz, Zagórda Mirosław, Kiełbasa Paweł

Przegląd Elektrotechniczny

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2020

|

R. 96, nr 2

137--141

PL

W artykule przedstawiono relacje między stopniem zagęszczenia gruntu określonym penetrometrem stożkowym, przewodnością elektryczną gruntu na wybranych głębokościach jego profilu określoną konduktometrem oraz echogramem wykonanym georadarem. Badania przeprowadzono w warunkach rzeczywistych a do zagęszczania gruntu wykorzystano ciągnik rolniczy wyposażony w standardowe opony. Zidentyfikowano istotną zbieżność wyników pomiarów dla wszystkich metod pomiarowych, która pozwala stosować je wymiennie do identyfikacji nadmiernego zagęszczenia gruntu np. śladów przejazdu maszyn a także innych anomalii w zagęszczeniu gruntu pod warunkiem istnienia wyrównanych parametrów wilgotnościowych mierzonego ośrodka.

EN

The article presents the relationship between the degree of soil compaction determined by a cone penetrometer and soil electrical conductivity at selected depths of its profile determined by a conductometer and a GPR echogram. The tests were carried out in real conditions and an agricultural tractor equipped with standard tires was used for soil compaction. Significant convergence of measurement results was identified for all measurement methods, which allows them to be used interchangeably to identify excessive soil compaction, e.g. machine tracks, as well as other anomalies in soil compaction, provided that the humidity parameters of the measured medium are equal.

9

Agricultural Tile Drainage Detection within the Year Using Ground Penetrating Radar

Karásek Petr, Nováková Eva

Journal of Ecological Engineering

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2020

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Vol. 21, nr 4

203--211

EN

The aim of this study was to identify the tile drainage systems within the year (from spring to autumn) using the ground penetrating radar (GPR) geophysical method. The measurements were performed in the experimental locality Dehtáře in the Bohemo-Moravian Highland (Czech Republic) in the years 2016 and 2017. The profiles located in the drained area were repeatedly measured together with the drainage discharges, soil moisture and groundwater level. The best visibility of tile drains was observed during snowmelt (in March and April) when the drainage discharges usually reach their maximum. In other months, the visibility of the drains was variable, but mostly worse. For a reliable detection of individual drains, the measurements above the drainage must be performed in several profiles. Under the conditions of the Czech Republic, the best results were obtained by a 500 MHz frequency antenna.

10

Implementation of GPR and TLS data for the assessment of the bridge slab geometry and reinforcement

Cafiso S., Di Graziano A., Goulias D., Mangiameli M., Mussumeci G.

Archives of Civil Engineering

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2020

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Vol. 66, nr 1

297--308

EN

This paper presents a suggested approach for forensic investigation of bridge decks in which Ground penetrating radar (GPR) consisting of two antennas is used to assess the current conditions. The methodology was tested on a bridge deck in central Sicily. The acquired data were analyzed for identifying the asphalt overlay thickness, concrete cover depth and deck thickness and location of the rebar reinforcement. In the proposed approach for assessing bridge deck conditions the GPR survey was complemented with (i) a site investigation on layer thicknesses for calibration/verification purposes of the GPR response and (ii) a Terrestrial Laser Scanning system (TLS) to verify the bridge design slab curvature. The study shows that this methodology has significant merits on accurately assessing such bridge deck components when bridge design records are non-existing, and by using non-invasive methods such as laser scanning and GPR. The great advantage provided by the TLS technique is the possibility to obtain a 3D output model of the scanned element with the accuracy of the best topographic instruments in order to complement GPR data surveys for bridge inspection.

11

GPR as a support tool in determining the causes of failure of objects built in the “white box” technology

Lejzerowicz A., Wutke M.

Archives of Civil Engineering

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2020

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Vol. 66, nr 3

173--189

EN

From the construction made in the “white box” technology, first of all tightness is required - on the structural elements there should not be any cracks or scratches, through which water could penetrate, which in consequence may lead to deformation of structural elements and even loosing of their load-bearing capacity. Among the methods enabling the location of weakened places in watertight concrete, the ground penetrating radar (GPR) method is effective because the local occurrence of water in the structure evokes a clear and unambiguous anomaly on the radargram. In addition, the GPR method allows you to indicate places where water flows without the necessity of excluding the object from use and interference in the construction layers. The designation of such locations will make it possible to undertake technical activities that can facilitate the takeover of water and thus ensure the desired load-bearing capacity and usability of the object. Using the GPR method, you can also designate places that have already been deformed – discontinuities or breaking. The article presents a case study of investigations that determine the causes of leakage of tunnels made in the “white box” technology in: twice within the bottom slab of the tunnel (1 GHz air-coupled and 400 MHz ground-coupled antenna) and once in the case of tunnel walls (1.6 GHz ground-coupled antenna).

PL

Od konstrukcji wykonanej w technologii "białej wanny" wymagana jest przede wszystkim szczelność - na elementach konstrukcyjnych nie powinno być żadnych pęknięć ani zadrapań, przez które woda może przenikać, ponieważ to w konsekwencji może prowadzić do deformacji elementów konstrukcyjnych, a nawet utraty ich nośności. Wśród metod umożliwiających lokalizację osłabionych miejsc w wodoszczelnym betonie, metoda georadarowa (ang. ground penetrating radar - GPR), jest skuteczna, ponieważ lokalne występowanie wody w strukturze wywołuje wyraźną i jednoznaczną anomalię na otrzymanym obrazie (radargramie). Ponadto metoda GPR pozwala wskazać miejsca, w których woda przepływa bez konieczności wyłączania obiektu z użytkowania i bez ingerowania w warstwy konstrukcyjne. Wyznaczenie takich miejsc umożliwia podjęcie działań technicznych, które mogą ułatwić przejęcie wody, a tym samym zapewnić pożądaną nośność i użyteczność obiektu. Za pomocą metody GPR można również wyznaczyć miejsca, które zostały już zdeformowane – miejsca nieciągłości lub ugięć czy spękań. Artykuł przedstawia studium przypadku oraz badania, które umożliwiły określenie przyczyny wycieku w obrębie tunelu wykonanego w technologii "białej wanny" - w obrębie płyty dennej tunelu (z wykorzystaniem anteny o częstotliwości 1 GHz sprzężonej z powietrzem oraz z wykorzystaniem anteny o częstotliwości 400 MHz sprzężonej z ziemią), jak również w przypadku ścian tunelu (antena o częstotliwości 1,6 GHz sprzężona z ziemią).

12

GPR surveying method as a tool for geodetic verification of GESUT database of utilities in the light of BSI PAS128

Gabryś Marta, Kryszyn Katarzyna, Ortyl Łukasz

Reports on Geodesy and Geoinformatics

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2019

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Vol. 107

49--59

EN

Intensified investment processes in construction have resulted in increased interest in the methods of efficient detection, verification and location of underground utility networks. In addition to the well-known pipe and cable locating equipment, which has increased its efficiency and reliability through the development of technologies, GPRs are becoming more and more popular. This publication presents the results of the experimental research carried out with the use of GPRs manufactured by two different companies as well as the results of the verification of underground utilities in real conditions. The GPRs have worked in the mode of the real-time location of their own position using the GNSS system or robotic total stations. The GPR (Ground Penetrating Radar) surveys performed on a test field, consisting of 9 pipes with a known position, were aimed at assessing the accuracy of their identification on echograms. The utility line location errors were determined using three different combinations between the GPR and the locating instrument. It allowed the evaluation of the possibility of using these solutions for detection, verification and location of underground utility networks in the light of the Polish legal regulations and the British specification PAS 128. The verification in real conditions was carried out in a typical urban space, characterised by an intense occurrence of underground utilities, that is, sewage systems, gas pipelines and power cables. It was based on the GESUT database captured from the county geodetic and cartographic documentation centre. The results of the visual analysis of the materials captured with the help of two measurement systems were described in detail, however, the verification was carried out only for one set of data. The authors have presented the procedure of processing echograms and detecting the location of pipeline axes based on their vectorisation. The authors of this research paper have performed a numerical analysis of the compliance of the profiles of utility lines with the information from the base map for two variants of the GPR data integration with the coordinates. The authors of this research paper have also presented an alternative concept of capturing the profile of a utility line in the field based on the processing of GPR data in 3D – the so-called C-scan. The conclusions summarise the possible factors affecting the surveying results and the methods of eliminating sources of errors, both for the GPR and geodetic data.

13

Geometryzacja form zjawisk krasowych na podstawie badań metodą georadarową

Ortyl Łukasz

Przegląd Geologiczny

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2019

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Vol. 67, nr 4

252--269

EN

Recognition of subsoil in areas threatened with discontinuous deformation associated with the existence of natural and mining voids can be implemented by various geophysical methods. The purpose of such research, apart from confirming the existence of voids, is to determine their spatial extent. This is not a simple issue, regardless of the geophysical method used. This paper discusses the possibilities of geometrization of karst phenomenon localization using the ground penetrating radar (GPR) method by the example of a karst cave as a natural void. The area of data acquisition is located on limestone formations with numerous karstforms. The study object is the main hall of the karst cave with a height of up to 3 m, located at a depth of 3 to 7 m below the surface. Such location and shape of the subsurface structure made it possible for the author to perform a wide range of research. Their original aspects are presented in this paper. The shape of the hall was obtained using terrestrial laser scanning (TLS). The GPR data were obtained employing the 250 MHz shielded antenna that was directly positioned using a robotized total station with the option of automatic target tracking. Thus, the GPR and geodetic data were immediately achieved in a uniform coordinate system. The accuracy of the data obtained in this way is discussed in this paper. The author’s original algorithm for processing of GPR data into a point cloud is presented. Based on the results obtained, it was possible to compare the GPR signal, which represents the shape of the cave hall, in relation to its image in the form of a point cloud from terrestrial laser scanning. A unique part of this paper is the selection of filtration procedures and their parameters in optimal GPR data processing, which were widely discussed and documented in a way beyond the standard filtration procedures. A significant contribution is the analysis that was carried out on the data obtained in the field and on the model data generated using the finite difference method. Modeling was carried out for two wave sources: exploding reflector and point. The presented methodology and discrimination between the actual shape of the cave, GPR field data and model data made it possible for the author to draw many conclusions related to the possibilities of shape geometrization of the subsurface voids determined by the GPR method.

14

Finite-difference time domain (FDTD) modeling of ground penetrating radar pulse energy for locating burial sites

Akinsunmade Akinniyi, Karczewski Jerzy, Mazurkiewicz Ewelina, Tomecka-Suchoń Sylwia

Acta Geophysica

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2019

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Vol. 67, no. 6

1945--1953

EN

Analysis of the finite-difference time domain (FDTD) numerical simulation of ground penetrating radar (GPR) measurement for locating burial sites is described in this paper. Effective, efficient, and reliability interpretation of GPR field data obtained from clandestine sites is very crucial in forensic investigations. The main goal of the study is the prediction of the change in the interaction of the electromagnetic incident on changes in buried bodies with time. In order to achieve this, the research involves the modeling of the GPR electromagnetic pulse energy responses to simulated changes in buried body with time with a view to understand what the results of real field measurement will give. The field measurements were conducted with GPR system manufactured by Mala Geoscience with antennae frequency of 500 MHz, 250 MHz, and 100 MHz. Responses from both synthetic and field radargrams depict the target was intercepted at same time (approximately 25 ns). The results have demonstrated that FDTD modeling is an important tool for enhancing the reliability of GPR data interpretation particularly for forensic study.

15

The application of non-standard GPR techniques for the examination of river dikes

Gołębiowski T., Małysa T.

Technical Transactions

|

2018

|

Vol. 115, iss. 7

121-138

EN

A standard measurement procedure currently applied in the ground penetrating radar (GPR) method is shortoffset reflection profiling. As this procedure delivers data that is suited only for qualitative interpretation, its application should be limited exclusively to reconnaissance surveys. There are various other techniques used in GPR surveying that may be regarded as non-standard, such as multi-offset and adaptable-polarisation surveying and tomography. Because these techniques deliver information that allows for quantitative interpretation, they could be applied for the detailed examination of geological media and investigations of various buried anthropogenic targets. This paper focuses on the application of non-standard GPR techniques for the detection of high-porosity zones in river dikes. Results from both field surveys and numerical modelling are presented.

PL

Standardową techniką pomiarową stosowaną obecnie w metodzie georadarowej (GPR) jest krótkooffsetowe profilowanie refleksyjne. Technika ta dostarcza jedynie informacji do interpretacji jakościowej, więc powinna być stosowania tylko w badaniach rekonesansowych. W metodzie GPR jest kilka technik pomiarowych, które można uznać obecnie za niestandardowe, tzn. badania zmienno-offsetowe i zmiennopolaryzacyjne oraz tomografia otwór–otwór i otwór–powierzchnia. Techniki niestandardowe dostarczają informacji do interpretacji ilościowej więc powinny być stosowane w szczegółowych badaniach ośrodka geologicznego i obiektów antropogenicznych. W artykule skupiono się na zastosowaniu niestandardowych technik pomiarowych do wykrywania stref podwyższonej porowatości w wałach przeciwpowodziowych. W pracy przedstawiono wyniki pomiarów terenowych oraz modelowań numerycznych.

16

Application of ground penetrating radar method combined with sedimentological analyses in studies of glaciogenic sediments in central Poland

Lejzerowicz A., Wysocka A., Kowalczyk S.

Studia Quaternaria

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2018

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Vol. 35, Nr 2

103--119

EN

GPR method is perfectly suited for recognizing of sedimentary facies diversity in shallowly occurring sediments if there is a contrast of electrical properties between and/or within each layer. The article deals with the issue of the correlation between GPR surveys results and sedimentological analyses. As a result of this correlation a conceptual model of depositional systems of studied areas was developed. Studies were performed in two areas located in central Poland, where glacial deposits formed in the Middle Polish (Saalian) Glaciation are present. The study was based on 49 sediment samples and 21 GPR profiles. Analyses of litho facies as well as granulometric and mineralogical composition of deposits of collected samples were carried out, showing the diversity of glacial deposits in both study sites. During GPR measurements shielded antenna with a frequency of 500 MHz was used which allowed high-resolution mapping of the internal structure of deposits and to identify four characteristic radar facies. Correlation of GPR profiles with point, one-dimensional sedimentological studies allowed the unambiguous interpretation of the GPR image and draw conclusions about the formation environment of individual units. Geophysical and sedimentological data obtained during study provide a new and detailed insight into selected glacial deposits in central Poland.

17

Zastosowanie metody georadarowej w celu lokalizacji zawilgocenia w konstrukcji nawierzchni jezdni

Wutke M.

Materiały Budowlane

|

2018

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nr 7

54--57

PL

Zawilgocenie nawierzchni drogowej wpływa negatywnie na jej właściwości mechaniczne. Dostępne są różne metody oceny nawierzchni drogowych pod kątem zawilgocenia. Najprostsze w interpretacji metody grawimetryczne wymagają inwazyjnej ingerencji w stan nawierzchni i pomiarów wagowych w warunkach laboratoryjnych pobranych próbek. Istnieją także metody nieniszczące, m.in. metoda georadarowa. W artykule przedstawiono ocenę zawilgocenia za pomocą metody georadarowej na odcinku drogi długości 200 m, prowadzącej przez tunel wybudowany w technologii „białej wanny” z nawierzchnią w postaci warstwy asfaltowej grubości 12 cm, ułożonej na warstwie kruszywa grubości 20 cm. Po ok. pięciu latach użytkowania drogi zaobserwowano na niej wysięki w postaci mokrych plam. Zauważono także deformację w formie wyniesienia (wybrzuszenia) warstw asfaltowych. Georadar umożliwił zlokalizowanie miejsc zawilgoconych w obu warstwach nawierzchni drogowej i podanie przyczyny powstawania deformacji i wysięków wody na nawierzchni drogi.

EN

The presence of water in the road structure has a negative impact on its mechanical properties. Various methods are available for assessing roads in terms of their humidity. The simplest in interpretation - gravimetric methods - require invasive intervention in the road condition and measurements of weights of the samples in laboratory conditions. There are also non destructive methods, among them the Ground Penetrating Radar (GPR). The article presents the assessment of moisture using the GPR on a 200-meter section of the road leading through a tunnel built in the „white box” technology with road surface built of 12-centimeter of asphalt layer on 20-centimeter of aggregate. After about 5 years of use, there were wet spots on the road and deformation of asphalt layers in the formof elevation. GPR made it possible to locate wet areas in both layers and point the probable reasons of the deformation and wet spots on the road surface.

18

Wykorzystanie georadaru w ocenie podłoża gruntowego

Zabielska-Adamska K., Konopko M.

Materiały Budowlane

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2018

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nr 3

24--25

PL

Metoda GPR jest bezinwazyjną techniką dostarczającą informacji o obecności, sposobie i głębokości zalegania obiektów podziemnych oraz o budowie geologicznej badanego terenu. W badaniu wykorzystywane są różnice pomiędzy stałymi dielektrycznymi, odmiennymi dla każdego z analizowanych ośrodków, a wśród czynników niezbędnych do zarejestrowania użytecznego sygnału (informacji) jest wyraźny kontrast pomiędzy stałą dielektryczną poszukiwanego obiektu a jego otoczenia. W artykule pokazano, że technika georadarowa pozwala ustalić nie tylko głębokość zalegania zwierciadła wód gruntowych, ale też zobrazować granice poszukiwanych utworów. Może więc stanowić uzupełnienie tradycyjnych metod in situ, ułepszając tym samym ocenę podłoża gruntowego. Sprawdza się także w lokalizowaniu wszelkiego rodzaju rur, kabli i innych anomalii występujących w podłożu gruntowym.

EN

GPR method is a non-invasive technique for ground exploration which detects subsurface objects and assesses their presence, as well as provides information about the geological structure of investigation site. GPR method takes advantage of the differences between the dielectric constants, specific for the material under analysis. One of the factors that are essential to record reliable data is a clear contrast between the dielectric constant of investigated object and of its surroundings. The paper shows that GPR technique is able to detect not only level of the groundwater table, but also the boundaries of soil layers. Therefore, it may successfully complement traditional in situ methods which considerably improves ground assessment. Moreover, it serves well to identify various kinds of pipes, wires and other anomalies that may be found underground.

19

Analogue GPR study of the Permian fanglomerates from Zygmuntówka Quarry near Chęciny, Holy Cross Mountains, southern Poland, for construction of a training image for multiple point simulations

Żuk T., Małolepszy Z., Szynkaruk E.

Geological Quarterly

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2018

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Vol. 62, No. 4

755--766

EN

The distribution of Permian alluvial fan lithofacies in a quarry at Zygmuntówka near Chęciny, Holy Cross Mts., in southern Poland was investigated using ground penetrating radar (GPR) in order to create a training image for multiple point statistics (MPS) reconstructions of alluvial fan sedimentary facies. Five pseudo-3D GPR datasets were collected, processed and uploaded for interpretation into SKUA-GOCAD 3D geological modelling software. Three radar facies were distinguished based on the 3D geometrical pattern of radar reflections and linked to lithofacies described from the quarry by Zbroja et al. (1998). A statistical summary showed that ~50% of the lithofacies resulted from gravity flows (mostly non-cohesive), while the remaining proportion was deposited by unconfined and confined flash floods. Fluvial sedimentary facies left by waning of catastrophic floods or reworking during fair weather, alihough not prevalent, could not be distinguished from confined flood deposits based only on GPR data. The GPR datasets together with information from field observations were used to carry out MPS simulations and estimate the most probable 3D model of lithofacies at the quarry scale. This model will in turn serve as a training image for MPS reconstructions of alluvial-fan facies of Rotliegend conglomerates in the multi-scale geological model of the Gorzów Block (western Poland).

20

Combined GPR data analysis technique for diagnostics of structures with thin near-surface layers

Batrakov D. O., Batrakova A. G., Antyufeyeva M. S.

Diagnostyka

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2018

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Vol. 19, No. 3

11--20

EN

A method of processing GPR signals based on previously developed algorithms is proposed. The purpose of the study is to increase the accuracy of thickness measurements of near-surface thin layers of multilayer structures. The main idea of the method is to layer-by-layer restoration of physical and geometric characteristics of plane-layered media, for example, car coverings. As a result, with the help of numerical modelling, the operability and practical effectiveness of the proposed method was established. In addition, schemes for the practical implementation of this approach have been proposed for the processing of sounding data of pavement structures using a pulsed ground-penetrating radar "TRF-1". The use of additional procedures, for example, GPR calibration based on data obtained by core sampling, also improves the reliability and accuracy of assessing the current state of road pavements.