scholarly journals Application of georadars for detecting subsurface defects in layers of non-rigid road pavements

2020 ◽  
Keyword(s):  
Low Cost ◽  
Calibration Method ◽  
Point Of View ◽  
Thin Layers ◽  
Building Structures ◽  
Destructive Testing ◽  
Road Pavement ◽  
Current State ◽  
Ground Penetrating ◽  
Non Destructive

The relevance of the problem under consideration is a consequence of the high cost of classical methods of pavement inspection. At the same time, the use of modern pulse georadars allows to ensure a relatively low cost of monitoring the current state of highways, since it allows to obtain georadar data when a laboratory vehicle is moving at the speed of a traffic flow. This minimizes the role of costly and time-consuming operations such as coring or cutting. The purpose of this work is to improve the methods for obtaining primary GPR data, which were previously proposed by the authors to improve the accuracy and reliability of the results of processing pulsed GPR signals. Materials and methods. When processing model and experimental data, first of all, modern theoretical methods of processing pulse signals from ground penetrating radars, as well as methods of computer modeling, were used. Results. Based on the analysis of the factors that determine the key features of GPR signals, a signal calibration method has been proposed, which makes it possible to increase the reliability of detecting such defects in layers of non-rigid road pavement made of monolithic materials, such as loss of interlayer adhesion, or identification of thin layers from an electrophysical point of view in multilayer media. Conclusions. Combining the signal calibration method together with the previously proposed approach to detecting the loss of interlayer adhesion and the performed numerical simulation made it possible to increase the reliability of the procedure for non-destructive testing of road pavements and other building structures. During the work, laboratory experiments were performed on model structures. The analysis of the obtained data was performed using the developed software GeoVizy.

scholarly journals Nonlinear spectral correction of the pulse GPR signals

2018 ◽  
Keyword(s):  
Thickness Measurement ◽  
Point Of View ◽  
Building Structures ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Electromagnetic Pulses ◽  
Industrial Structures ◽  
The One ◽  
Ground Penetrating ◽  
Non Destructive

Background: The problems of non-destructive testing of industrial structures and transport structures are relevant from the point of view of increasing the efficiency of their control systems and saving financial resources and materials. The relevance of scientific research in the field of remote sensing and methods for solving inverse problems is also associated with the prospects for the formulation and solution of biomedicine problems associated with computer technology. Objectives of the work is to study the possibilities of virtual adjustment of the properties of probing and reflected signals to increase the reliability of processing results and increase the accuracy of restoration of the properties of objects when solving thickness measurement problems. Materials and methods: The basis of the proposed approach is the correction of the amplitudes of pulse signals in order to increase the accuracy of the values ​​obtained as a result of processing by introducing a normalizing factor into the processing algorithm, the value of which would be a function obtained as a result of GPR calibration procedures. Another way to increase the reliability of the data processing procedure may be by computer correction of the waveform to approximate its shape to the shape of an idealized model pulse. Results: As a result of theoretical analysis, methods and algorithms for implementing the procedure for improving the processing of sets of primary sensing data obtained using pulsed georadars were proposed. Conclusion: The analysis of the methods for processing and adjusting the characteristics of pulsed ground-penetrating radar signals made it possible on the one hand to better understand the physical basis for the interaction of electromagnetic pulses with plane-layered media. On the other hand, practical methods of improving the quality control of various engineering and transport structures, as well as building structures, are proposed.

Non-Destructive Testing of Building Objects Positioned in the Area of Coal Exploitation

2012 ◽  
Vol 518 ◽  
pp. 228-237
Author(s):  
Andrzej Staniek
Keyword(s):  
Modal Analysis ◽  
Laser Scanning ◽  
Element Model ◽  
The State ◽  
Point Of View ◽  
Impact Excitation ◽  
Laser Vibrometer ◽  
Building Structures ◽  
Destructive Testing ◽  
Non Destructive

In this paper the results of modal analysis of a four storey building are presented. To excite the investigated structure, impact excitation was applied in two different points located on pillars supporting the building. In order to extract dynamic parameters of the structure, experimental modal analysis was applied. The parameters of vibration resulting from this excitation were measured by a scanning laser vibrometer; additionally piezoelectric accelerometers were utilized. To compare the results and monitor the state of the building a finite element model (FE) was built. It seems that a reliable identification of the state of building structures using a laser scanning vibrometer is feasible and relevant from a practical point of view. To monitor local changes additional piezoelectric accelerometers should be used. Moreover, it is applicable for damage detection to refine theoretical and experimental modal models for each natural frequency and to calculate the stress distribution for each refined model. Consequently, the sum of these particular stresses conveys information for building engineers and enables comparison with their in situ observations. The analysed building is situated on the terrain of underground coal mine exploitation so the aim of the research is not only to observe the state of the building but also to analyse possible changes during the process of excavation and after it was completed.

scholarly journals Editorial for the Special Issue “Advanced Techniques for Ground Penetrating Radar Imaging”

2021 ◽  
Vol 13 (18) ◽  
pp. 3696
Author(s):  
Yuri Álvarez López ◽  
María García-Fernández
Keyword(s):  
Ground Penetrating Radar ◽  
Radar Imaging ◽  
Non Destructive Testing ◽  
Special Issue ◽  
Destructive Testing ◽  
Subsurface Sensing ◽  
Key Technologies ◽  
Ground Penetrating ◽  
Non Destructive

Ground Penetrating Radar (GPR) has become one of the key technologies in subsurface sensing and, in general, in Non-Destructive Testing (NDT), since it is able to detect both metallic and nonmetallic targets [...]

scholarly journals ROAD PAVEMENT DENSITY ANALYSIS USING A NEW NON-DESTRUCTIVE GROUND PENETRATING RADAR SYSTEM

2010 ◽  
Vol 21 ◽  
pp. 399-417
Author(s):  
Mardeni Bin Roslee ◽  
Raja Syamsul Azmir Raja Abdullah ◽  
Helmi Zulhaidi bin Mohd Shafr
Keyword(s):  
Ground Penetrating Radar ◽  
Radar System ◽  
Road Pavement ◽  
Density Analysis ◽  
Ground Penetrating ◽  
Non Destructive

scholarly journals Advanced GPR Signal Processing Techniques for Root Detection in Urban Environments

2020 ◽  
Author(s):  
Livia Lantini ◽  
Fabio Tosti ◽  
Iraklis Giannakis ◽  
Kevin Jagadissen Munisami ◽  
Dale Mortimer ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Root Systems ◽  
Urban Environments ◽  
Street Trees ◽  
Destructive Testing ◽  
Root Detection ◽  
Charitable Trust ◽  
Ground Penetrating ◽  
Processing Techniques ◽  
Non Destructive

<p>Street trees are widely recognised to be an essential asset for the urban environment, as they bring several environmental, social and economic benefits [1]. However, the conflicting coexistence of tree root systems with the built environment, and especially with road infrastructures, is often cause of extensive damage, such as the uplifting and cracking of sidewalks and curbs, which could seriously compromise the safety of pedestrians, cyclists and drivers.</p><p>In this context, Ground Penetrating Radar (GPR) has long been proven to be an effective non-destructive testing (NDT) method for the evaluation and monitoring of road pavements. The effectiveness of this tool lies not only in its ease of use and cost-effectiveness, but also in the proven reliability of the results provided. Besides, recent studies have explored the capability of GPR in detecting and mapping tree roots [2]. Algorithms for the reconstruction of the tree root systems have been developed, and the spatial variations of root mass density have been also investigated [3].</p><p>The aim of this study is, therefore, to investigate the GPR potential in mapping the architecture of root systems in street trees. In particular, this research aims to improve upon the existing methods for detection of roots, focusing on the identification of the road pavement layers. In this way, different advanced signal processing techniques can be applied at specific sections, in order to remove reflections from the pavement layers without affecting root detection. This allows, therefore, to reduce false alarms when investigating trees with root systems developing underneath road pavements.</p><p>In this regard, data from trees of different species have been acquired and processed, using different antenna systems and survey methodologies, in an effort to investigate the impact of these parameters on the GPR overall performance.</p><p> </p><p><strong>Acknowledgements</strong></p><p>The authors would like to express their sincere thanks and gratitude to the following trusts, charities, organisations and individuals for their generosity in supporting this project: Lord Faringdon Charitable Trust, The Schroder Foundation, Cazenove Charitable Trust, Ernest Cook Trust, Sir Henry Keswick, Ian Bond, P. F. Charitable Trust, Prospect Investment Management Limited, The Adrian Swire Charitable Trust, The John Swire 1989 Charitable Trust, The Sackler Trust, The Tanlaw Foundation, and The Wyfold Charitable Trust. This paper is dedicated to the memory of our colleague and friend Jonathan West, one of the original supporters of this research project.</p><p> </p><p><strong>References</strong></p><p>[1] J. Mullaney, T. Lucke, S. J. Trueman, 2015. “A review of benefits and challenges in growing street trees in paved urban environments,” Landscape and Urban Planning, 134, 157-166.</p><p>[2] A. M. Alani, L. Lantini, 2019. “Recent advances in tree root mapping and assessment using non-destructive testing methods: a focus on ground penetrating radar,” Surveys in Geophysics, 1-42.</p><p>[3] L. Lantini, F. Tosti, Giannakis, I., Egyir, D., A. Benedetto, A. M. Alani, 2019. “A Novel Processing Framework for Tree Root Mapping and Density Estimation using Ground Penetrating Radar,” In 10th International Workshop on Advanced Ground Penetrating Radar, EAGE.</p>

scholarly journals Lab Non Destructive Test to Analyze the Effect of Corrosion on Ground Penetrating Radar Scans

2019 ◽  
Vol 11 (23) ◽  
pp. 2814 ◽  
Author(s):  
Sossa ◽  
Pérez-Gracia ◽  
González-Drigo ◽  
Rasol
Keyword(s):  
Ground Penetrating Radar ◽  
Wave Amplitude ◽  
Metallic Surface ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Accurate Analysis ◽  
Reflected Wave ◽  
Dense Grid ◽  
Ground Penetrating ◽  
Non Destructive

Corrosion is a significant damage in many reinforced concrete structures, mainly in coastal areas. The oxidation of embedded iron or steel elements degrades rebar, producing a porous layer not adhered to the metallic surface. This process could completely destroy rebar. In addition, the concrete around the metallic targets is also damaged, and a dense grid of fissures appears around the oxidized elements. The evaluation of corrosion is difficult in early stages, because damage is usually hidden. Non-destructive testing measurements, based on non-destructive testing (NDT) electric and magnetic surveys, could detect damage as consequence of corrosion. The work presented in this paper is based in several laboratory tests, which are centered in defining the effect of different corrosion stage on ground penetrating radar (GPR) signals. The analysis focuses on the evaluation of the reflected wave amplitude and its behavior. The results indicated that an accurate analysis of amplitude decay and intensity could most likely reveal an approach to the state of degradation of the embedded metallic targets because GPR images exhibit characteristics that depend on the effects of the oxidized rebar and the damaged concrete. These characteristics could be detected and measured in some cases. One important feature is referred to as the reflected wave amplitude. In the case of corroded targets, this amplitude is lower than in the case of reflection on non-oxidized surfaces. Additionally, in some cases, a blurred image appears related to high corrosion. The results of the tests highlight the higher amplitude decay of the cases of specimens with corroded elements.

Modelling the Magnetic Characteristics and Temperature Influence on Construction Steels

2013 ◽  
Vol 199 ◽  
pp. 466-471 ◽  
Author(s):  
Dorota Jackiewicz ◽  
Roman Szewczyk ◽  
Jacek Salach
Keyword(s):  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Point Of View ◽  
Magnetic Characteristics ◽  
Extended Model ◽  
Destructive Testing ◽  
Influence Of Temperature On ◽  
Stress Estimation ◽  
As Stress ◽  
Non Destructive

This paper concerns the possibility of use of the Jiles-Atherton-Sablik extended model to describe the magnetic characteristics for construction steel ST3. Result of the modelling utilizing extended Jiles-Atherton-Sablik model are in good agreement with results of experimental measurements for magnetic hysteresis loops B(H). However experimental results indicated, that the influence of temperature on B(H) characteristics is relatively small and can be neglected from the point of view of modelling for technical applications, such as stress estimation for non-destructive testing.

METHODS OF ACOUSTIC EMISSION ESTIMATION OF NANO-CHARACTERISTICS OF THE STRENGTH OF STRUCTURAL AND ENGINEERING MATERIALS OF THE OBJECTS

2019 ◽  
pp. 44-57 ◽  
Author(s):  
V. V. Nosov ◽  
E. V. Grigoriev
Keyword(s):  
Acoustic Emission ◽  
Multilevel Model ◽  
Point Of View ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Kaiser Effect ◽  
Operational Level ◽  
Real Objects ◽  
Emission Estimation ◽  
Non Destructive

The acoustic emission method is the most promising metrological basis for non-destructive testing of strength. The necessity of solving problems of acoustic emission prediction of fracture and the ambiguity of the connection of the results of acoustic emission tests makes the problem of modeling strength heterogeneity relevant; it suggests a transition to a more complex level of research. The complexity of predicting the behavior of heterogeneous materials necessitates modeling and determining the parameters of the fracture process at the nano-defining operational level and the need to interpret the Kaiser effect revealing the strength heterogeneity as a phenomenon of a decrease in the activity of elastic radiation upon application of repetitive loads on the object under control. Heterogeneity modeling requires determining of its type, criterion and approach to estimation. The type of heterogeneity depends on the solved problem and has to be associated with the property that determines the function of real objects. Also, the criterion should be informative and the method of its evaluation should be non-destructive. Examples of modeling the temporal dependences of the AE parameters under conditions of strength heterogeneity are given, the analysis is carried out and the Kaiser effect is estimated from the point of view of a multilevel model of the dependences of the temporal parameters of acoustic emission.

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