scholarly journals Frequency components of radargrams in analyses of shallow soil cavities

2018 ◽  
Vol 7 (2.13) ◽  
pp. 127
Author(s):  
Daniliev S.M ◽  
Danilieva N.A
Keyword(s):  
Electromagnetic Wave ◽  
Ground Penetrating Radar ◽  
Large Scale ◽  
Experimental Studies ◽  
Technical Condition ◽  
Filling Material ◽  
Field Frequency ◽  
Inverse Fourier Transformation ◽  
Industrial Buildings ◽  
Ground Penetrating

The urgency of the issue being studied is determined by widespread large-scale implementation of ground penetrating radar (GPR) method within the study practice of technical state of various engineering-geological sites over a long operational period. Such buildings and structures as dams, architectural landmarks, residential and industrial buildings, temples and churches, roadways and takeoff runways may be referred to main engineering and geological sites which have been studied via ground penetrating radar method. Cracks of different length, orientation and opening, as well as cavities of various localization, being distinguished by filling material, are the main types of irregularities in the above-mentioned sites, which were being formed in the process of prolonged or improper operation. However, due to vastness of the irregularities being studied and the impossibility to include all the types of possible defects into this article, we have settled on the cavities which are the most commonly encountered in the course of practice only. This article considers the approach to analysis of the electromagnetic wave field frequency characteristics being applied during conducting ground penetrating radar studies of irregularities in the structure of engineering-geological sites on the basis of the results of electromagnetic wave fields mathematical simulation, and of the results obtained in experimental studies at real engineering-geological sites as well. There has been proposed a method based of inverse Fourier transformation for studying spectrum shift in georadargrams. The georadargram is a set of registered signals, which is obtained during even movement of the georadar along the survey line. Due to that, this article is aimed at attraction of analysis of wave electromagnetic field attributes in addition to standard methods of ground penetrating radar (GPR) data processing and interpretation, which allows to extend significantly prospect capabilities of GPR method by obtaining extra data on heterogeneous zones parameters at engineering and geological sites, and, thus, proceed from qualitative notions on technical condition of studied object to quantitative ones.  

scholarly journals Detection of Tree Roots in an Urban Area with the Use of Ground Penetrating Radar

2016 ◽  
Vol 17 (4) ◽  
pp. 362-370 ◽  
Author(s):  
Alexander Krainyukov ◽  
Igor Lyaksa
Keyword(s):  
Urban Area ◽  
Ground Penetrating Radar ◽  
Growth Direction ◽  
Technical Condition ◽  
Tree Roots ◽  
Secondary Processing ◽  
Non Invasive ◽  
Ground Penetrating ◽  
The Given

Abstract The paper is devoted to using ground penetrating radar (GPR) for the detection of tree roots in an urban area, since GPR allow detect the hidden objects in non invasive way. It is necessary exactly to know the growth direction, thickness and depth of the roots of the tree to confidently assert about the tree root influence on the technical condition of engineering objects and structures: of the buildings, of pavements, of roadway, of engineering communications and etc. The aim of the given research was experimentally to evaluation the possibilities of detection of tree roots in an urban area with the use of GPR on frequency 400 MHz and of algorithms of secondary processing of GPR signals. Results of interpretation of radar profile and evacuation of soil around tree show the possibility of detection of the tree roots and the determination of their parameters using one or two radar concentric profiles.

Non-Destructive Evaluation of Reinforcing Rebar Radius by Digital Image GPR Technique

2014 ◽  
Vol 501-504 ◽  
pp. 847-851
Author(s):  
Che Way Chang ◽  
Chen Hua Lin ◽  
Shyi Lin Lee ◽  
Ping Huang Chen ◽  
Ching Cheng Jen ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Behavior Analysis ◽  
Physical Model ◽  
Digital Image ◽  
Ground Penetrating Radar ◽  
High Efficiency ◽  
Non Destructive Evaluation ◽  
Energy Zone ◽  
Ground Penetrating ◽  
Non Destructive

Ground Penetrating Radar (GPR) is a high efficiency technology to detect the cylindrical medium in the concretes material. The electromagnetic wave is incidental to double-rebar, and measures the reflection signal behaviors from energy zone. The results from the reflection signal of electromagnetic wave of the reinforcement concretes allow evaluating the radius of double-bar (1.6cm, 1cm). A physical model can effectively measure the radius of double-bar by the result of electromagnetic wave reflex behavior analysis. The results indicate that, this techology is capable of estimating the reinforcing double-bar radius to within 6%.

Model Track Studies by Ground Penetrating Radar (GPR) on Ballast With Different Fouling and Geotechnical Properties

2015 ◽  
Author(s):  
Hamed Faghihi Kashani ◽  
Carlton L. Ho ◽  
Charles P. Oden ◽  
Stanley S. Smith
Keyword(s):  
Ground Penetrating Radar ◽  
Large Scale ◽  
Empirical Studies ◽  
Geotechnical Properties ◽  
Maintenance Cost ◽  
Non Invasive ◽  
Section Area ◽  
University Of Massachusetts ◽  
Ground Penetrating ◽  
The University

In recent years there has been an increase in the knowledge of, and need for, non-invasive monitoring of ballast in order to identify the problematic sections of track and decrease the maintenance cost. Various technologies such as Ground Penetrating Radar (GPR) are becoming accepted for investigating the condition of ballast. However since these techniques were not originally developed for engineering applications, their applicability in ballast evaluations can be sometimes uncertain. Continued empirical studies and condition specific calibrations are needed to demonstrate repeatable and quantifiable results. In this study large-scale track models with trapezoidal section area were constructed at the University of Massachusetts to investigate the effects of breakdown fouling, and the effects of changing geotechnical properties on GPR traces. This paper presents the design and construction of large scale track models, and methods used for GPR data collection. GPR data are presented in this paper that demonstrate sensitivity to the track model properties and variables. In particular, the experiments are being used to evaluate changes in GPR data with changing geotechnical properties of the ballast such as density, water content, grain size distribution (GSD), and fouling percentage.

scholarly journals Imaging the structure of cave ice by ground-penetrating radar

2011 ◽  
Vol 5 (2) ◽  
pp. 329-340 ◽  
Author(s):  
H. Hausmann ◽  
M. Behm
Keyword(s):  
Electromagnetic Wave ◽  
Internal Structure ◽  
Liquid Water ◽  
Ground Penetrating Radar ◽  
Wave Speed ◽  
Liquid Water Content ◽  
Thin Layers ◽  
Ice Formation ◽  
Alpine Regions ◽  
Ground Penetrating

Abstract. Several caves in high elevated alpine regions host up to several meters thick ice. The age of the ice may exceed some hundreds or thousands of years. However, structure, formation and development of the ice are not fully understood and are subject to relatively recent investigation. The application of ground-penetrating radar (GPR) enables to determine thickness, volume, basal and internal structure of the ice and provides as such important constraints for related studies. We present results from four caves located in the Northern Calcareous Alps of Austria. We show that the ice is far from being uniform. The base has variable reflection signatures, which is related to the type and size of underlying debris. The internal structure of the cave ice is characterized by banded reflections. These reflection signatures are interpreted as thin layers of sediments and might help to understand the ice formation by representing isochrones. Overall, the relatively low electromagnetic wave speed suggests that the ice is temperate, and that a liquid water content of about 2% is distributed homogenously in the ice.

Evaluation of Grouting Effect Detection in Goaf

2013 ◽  
Vol 438-439 ◽  
pp. 1080-1083 ◽  
Author(s):  
Hui Ren Bai ◽  
Jing Jing Li
Keyword(s):  
Electromagnetic Wave ◽  
Ground Penetrating Radar ◽  
Filling Method ◽  
Grouting Reinforcement ◽  
Ground Penetrating ◽  
Integrated Detection

The paper mainly introduces the problem of grouting reinforcement of buildings over the old goaf, and presents to the positioning of grouting reinforcement technology in the goaf. Combined with engineering example, the paper discusses the grouting filling method to strengthening governance goaf. Three methods including drill detection, ground penetrating radar (GPR) detection and electromagnetic wave CT method are used for integrated detection.

Ground-penetrating radar and coring used to study the large-scale structure of point-bar deposits in three dimensions

Sedimentology ◽  
1995 ◽  
Vol 42 (6) ◽  
pp. 839-852 ◽  
Author(s):  
JOHN S. BRIDGE ◽  
JAN ALEXANDER ◽  
RICHARD E. LL. COLLIER ◽  
ROB. L. GAWTHORPE ◽  
JACK JARVIS
Keyword(s):  
Ground Penetrating Radar ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Three Dimensions ◽  
Point Bar ◽  
Ground Penetrating

scholarly journals GPR APPLIED TO RIGID PAVEMENT FROM SANTOS DUMONT AIRPORT, RJ

2014 ◽  
Vol 32 (2) ◽  
pp. 225
Author(s):  
Welitom Rodrigues Borges ◽  
Luís Anselmo Da Silva ◽  
Luciano Soares Da Cunha ◽  
Raimundo Mariano Gomes Castelo Branco ◽  
Márcio Muniz de Farias
Keyword(s):  
Electromagnetic Wave ◽  
Ground Penetrating Radar ◽  
Rio De Janeiro ◽  
Concrete Slab ◽  
Geophysical Investigation ◽  
Rigid Pavement ◽  
Ground Penetration Radar ◽  
Speed Of Propagation ◽  
Ground Penetrating ◽  
Pavement Thickness

ABSTRACT. This paper presents the results of a research performed by using Ground Penetration Radar (GPR) to evaluate the structure of the rigid pavement ofSantos Dumont Airport in Rio de Janeiro, Brazil. The GPR data profiles were acquired with 250 and 700 MHz shielded antennas. The geophysical investigation wasperformed along of 6 profiles, totaling 1432 meters of GPR sections. For calibration of the speed of propagation of electromagnetic wave were drilled three boreholesuntil the depth of 1.8 m. The results of GPR allowed the precise delineation of reflectors related to geotechnical interfaces (pavement thickness – concrete slab andmacadam) and geological (sand/embankment soil), showing the efficiency of this method in this case study.Keywords: GPR, concrete, rigid pavement, Santos Dumont Airport. RESUMO. Este trabalho apresenta o resultado de uma pesquisa desenvolvida usando Ground Penetrating Radar (GPR) para avaliar a estrutura do pavimento rígido do pátio de manobras de aeronaves do Aeroporto Santos Dumont, no Rio de Janeiro, Brasil. Para isso foram usadas antenas blindadas com frequências de250MHz e de 700 MHz. Os dados de GPR foram adquiridos no modo common offset , ao longo de 6 perfis que totalizam 1432 metros de investigação. Para a calibração da velocidade de propagação da onda eletromagnética foram executados três furos de sondagem até a profundidade de 1,8 m. Os resultados de GPR possibilitaram odelineamento preciso de refletores relacionados a interfaces geotécnicas (espessura do pavimento – revestimento de concreto e do macadame) e geológicas (areia/aterrocom entulho), mostrando a eficiência da aplicação deste método neste estudo de caso.Palavras-chave: GPR, concreto, pavimento rígido, Aeroporto Santos Dumont.

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