scholarly journals Numerical Simulation Research on Response Characteristics of Grouting Defects of Ground Penetrating Radar for Detection of Grouting Quality behind Tunnel Wall

2021 ◽  
Vol 5 (4) ◽  
pp. 1-20
Author(s):  
D.Michelle Naomie Mavoungou ◽  
Pingsong Zhang ◽  
Siwei Zhang ◽  
Qiong Wang
Keyword(s):  
Ground Penetrating Radar ◽  
Radar Image ◽  
Tunnel Wall ◽  
Rectangular Crack ◽  
Reflected Wave ◽  
Quality Detection ◽  
Geological Conditions ◽  
Reflection Image ◽  
Ground Penetrating ◽  
Primary Support

The effect of grouting behind tunnel wall directly affects the surrounding ground settlement and the stability of tunnel structure, so the grouting quality detection is very necessary. As an efficient and convenient shallow geophysical exploration method, ground-penetrating radar can meet the high-resolution and non-destructive requirements of grouting quality detection behind the tunnel wall, so it is widely used in engineering in recent years. Most of the existing studies have obvious regional pertinence and special geological conditions, and there are few universal studies on the characteristics of the ground penetrating radar reflection image of the grouting defect behind the tunnel wall. In view of this, this paper uses the finite difference time domain method to simulate several grouting defects behind the wall, such as voids, water-bearing anomaly, cracks, and other grouting defects. The simulation results show that the reflection image of the direct wave is characterized by a white band with strong amplitude; the interface between primary support and second lining, primary support, and surrounding rock is also banded; the circular cavity and water anomaly characteristics are all hyperbolic, the difference is that the phase of the lower part of the radar image of the cavity anomaly is 0, and there are only hyperbolic tails on both sides, and the water-bearing anomaly also has obvious hyperbolic characteristics at each interface; the reflected wave characteristics of the rectangular crack are striped and watery and the reflected wave characteristic of rectangular cracks is striped, and the abnormal range of water-bearing cracks on the radar image is larger than that of air. The research results can provide an effective theoretical reference for the engineering application of ground penetrating radar detection of grouting defects behind the tunnel wall.

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.

The Application of Ground Penetrating Radar in Railway Tunnel Concrete Quality Detection

2011 ◽  
Vol 228-229 ◽  
pp. 1185-1189
Author(s):  
Su Qi ◽  
Xing Xing Chen
Keyword(s):  
Ground Penetrating Radar ◽  
Traditional Method ◽  
Detection Methods ◽  
Railway Tunnel ◽  
Testing Method ◽  
Quality Detection ◽  
Quality Testing ◽  
Concrete Quality ◽  
Ground Penetrating ◽  
Drilling Core

The priority of traditional tunnel concrete quality testing method is drilling core .The traditional method damage tunnel structure and detection speed is slowly.we use this method cann’t effectively meet the demand of rapid growth of tunnel concrete qulity testing. So the more fast and effective detection methods are needed.A new fast and effective kind of concrete quality detection methods is ground penetrating radar can meet the extensive tunnel concrete nondestructive testing. This paper introduces the basic principle of ground penetrating radar.I illustrate the application of railway tunnel testing by the testing in Ju Gan runnel of Lan Yue railway.TI is significance for railway tunnel concrete in future.

Application of Comprehensive Geological Exploration for Engineering Site Option

2011 ◽  
Vol 374-377 ◽  
pp. 2256-2260
Author(s):  
Sun Yong
Keyword(s):  
Ground Penetrating Radar ◽  
Geophysical Methods ◽  
High Density ◽  
Seismic Exploration ◽  
Accurate Analysis ◽  
Positive Role ◽  
Electrical Method ◽  
Study Results ◽  
Geological Conditions ◽  
Ground Penetrating

In the process of engineering prospective design and constructing, it is necessary to avoid the adverse impact of geological phenomena, such as fault, karst and landslide. Therefore, it’s important to choose a favorable project address by scientific and effective detection with engineering geological conditions. The main exploration method for geological conditions is the geophysical exploration, including: high density electrical method, ground penetrating Radar, seismic exploration method and so on. The discrimination result with a single geological method changes much, and it is difficult to make an accurate analysis of the geological conditions. So we should composite a variety of exploration methods. In this paper, it expounds the fundamental, the working method, data explanations of the high density electrical method and ground penetrating Radar firstly. And then it takes exploration of candidate sites of an aluminum waste disposal plant for example, the geological conditions of candidate sites are analyzed under the two geophysical methods. The study results of engineering site option have a positive role in guiding the work.

Application of the Ground Penetrating Radar in the Quality Detection of Tunnel Lining

2011 ◽  
Vol 243-249 ◽  
pp. 5381-5385 ◽  
Author(s):  
Ji Shun Pan ◽  
Lei Yang ◽  
Yuan Bao Leng ◽  
Zhi Quan Lv
Keyword(s):  
Data Processing ◽  
Ground Penetrating Radar ◽  
Tunnel Lining ◽  
Quality Detection ◽  
Steel Bar ◽  
Data Processing Method ◽  
Work Mechanism ◽  
Important Means ◽  
Working Principle ◽  
Ground Penetrating

Based on the ground penetrating radar's work mechanism, this article briefly introduces the working principle and the data processing method of ground penetrating radar detecting the tunnel lining. In view of the lining quality detection's characteristics, it summarizes a series of atlas reflection characteristic of the examination target such as the lining thickness, the backfill quality, the steel bar reinforcement situation, the adjacent formation structural feature and so on, and analyses and comments on them with project examples. The research believes that under appropriate working condition, as an important means to guarantee the construction security and maintain the tunnel health, ground penetrating radar technology can examine the lining quality fast and effectively, and meet the needs of the tunnel lining quality detection with suitable equipment, working method and data processing plan.

Application of Ground Penetrating Radar in Tunnel Concrete Lining Quality Detection

2014 ◽  
Vol 1065-1069 ◽  
pp. 358-363
Author(s):  
Meng Meng Zhang ◽  
Xie Dong Zhang
Keyword(s):  
Ground Penetrating Radar ◽  
Concrete Lining ◽  
Construction Process ◽  
Visual Measurement ◽  
Quality Detection ◽  
Media Distribution ◽  
Practical Engineering ◽  
Engineering Significance ◽  
Ground Penetrating ◽  
Frequency Impulse

Ground Penetrating Radar is a method using high frequency impulse electromagnetic wave to detect underground media distribution. It has been gradually widely used as it has the advantage of high accuracy, fast and nondestructive respecting to the conventional method such as visual measurement and confirmation with drilling hole. In the tunnel construction process, it is easy occurred that the quality problem of insufficient lining thickness, the distance of steel arch centering too large and the concrete disengaging. The work achieved in this paper based on the project of LongSheng tunnel and its conclusion and suggestion has important practical engineering significance.

scholarly journals Preliminary results of the ground penetrating radar (GPR) prospection in the area of the prehistoric flint mine Borownia, southeastern Poland

2014 ◽  
Vol 31 (2) ◽  
pp. 123-132
Author(s):  
Radosław Mieszkowski ◽  
Fabian Welc ◽  
Janusz Budziszewski ◽  
Witold Migal ◽  
Anna Bąkowska
Keyword(s):  
Ground Penetrating Radar ◽  
Central Zone ◽  
Archaeological Site ◽  
Depth Range ◽  
Good Resolution ◽  
Underground Structures ◽  
Preliminary Results ◽  
Geological Conditions ◽  
Prehistoric Mining ◽  
Ground Penetrating

Abstract Preliminary results of GPR field prospection carried out in the area of the prehistoric mining field Borownia (Ćmielów, Ostrowiec Świętokrzyski District) are presented. This mining field forms a belt (30-50 m wide and 700 m long), starting from the valley edge of the Kamienna River southeastwards. Southeastern and western parts of the site have preserved the original post-exploitation relief. Geology of the Borownia mining field was examined and acquired radiograms revealed three distinct zones of anomaly concentrations. The central zone (B) is clearly a fragment of the prehistoric mining field, confirmed not only by the GPR sounding but also by archeological surveys. The other two zones have not yet been investigated in detail yet but their surface and archaeological examination may determine only whether their underground structures are natural or have been created by humans. Data obtained during the GPR prospection at the Borownia archaeological site confirmed usefulness of 100, 250 and 500 MHz antennas. The relatively large depth range and good resolution are due to favorable geological conditions.

scholarly journals Application of Ground Penetrating Radar in Detecting Deeply Embedded Reinforcing Bars in Pile Foundation

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Daochuan Zhou ◽  
Haitang Zhu
Keyword(s):  
Ground Penetrating Radar ◽  
Pile Foundation ◽  
Field Testing ◽  
Radar Image ◽  
Reinforcing Bars ◽  
Raw Data ◽  
Centre Frequency ◽  
Wave Interference ◽  
Concrete Pile ◽  
Ground Penetrating

Ground penetrating radar (GPR) has been widely used for nondestructive testings in civil engineering. However, the GPR has not been adequately applied in detecting deeply embedded reinforcing bars, which is usually difficult to be revealed in radar image due to the wave interference and attenuation in large depth penetration. This study presents a new approach for the GPR detection of deeply embedded reinforcing bars in the reinforced concrete pile foundation. The aim of the GPR survey is to determine the existence and the depth of internal reinforcing bars in the pile foundation for solving engineering dispute. Low centre frequency antenna was used in GPR field testing to obtain the reflected raw data. Optimized procedures of digital filtering techniques were applied to process the GPR raw data. The deeply embedded reinforcing bars are revealed in the radar image after the field testing and postprocessing procedures. The depth of the reinforcing bars was estimated based on the hyperbola match method. The GPR test results were validated by the excavation of the pile foundation. The low centre frequency antenna has been found to be essential to obtain the reflected wave signals of deeply embedded reinforcing bars. The optimized processing procedures is useful to identify and display the reinforcing bars in radar image. The combination of low centre frequency antenna and the postprocessing procedures make the detection of deeply embedded reinforcing bars feasible. The proposed GPR testing method has been found to be effective to estimate the depth of deeply embedded reinforcing bars, which provides the key information for solving engineering dispute.

Crosshole reflection imaging with ground-penetrating radar data: Applications in near-surface sedimentary settings

Geophysics ◽  
2020 ◽  
Vol 85 (4) ◽  
pp. H61-H69
Author(s):  
Niklas Allroggen ◽  
Stéphane Garambois ◽  
Guy Sénéchal ◽  
Dominique Rousset ◽  
Jens Tronicke
Keyword(s):  
Ground Penetrating Radar ◽  
Field Data ◽  
Electromagnetic Property ◽  
Velocity Model ◽  
Radar Data ◽  
Near Surface ◽  
Velocity Models ◽  
Reflection Image ◽  
Detailed Interpretation ◽  
Ground Penetrating

Crosshole ground-penetrating radar (GPR) is applied in areas that require a very detailed subsurface characterization. Analysis of such data typically relies on tomographic inversion approaches providing an image of subsurface parameters. We have developed an approach for processing the reflected energy in crosshole GPR data and applied it on GPR data acquired in different sedimentary settings. Our approach includes muting of the first arrivals, separating the up- and the downgoing wavefield components, and backpropagating the reflected energy by a generalized Kirchhoff migration scheme. We obtain a reflection image that contains information on the location of electromagnetic property contrasts, thus outlining subsurface architecture in the interborehole plane. In combination with velocity models derived from different tomographic approaches, these images allow for a more detailed interpretation of subsurface structures without the need to acquire additional field data. In particular, a combined interpretation of the reflection image and the tomographic velocity model improves the ability to locate layer boundaries and to distinguish different subsurface units. To support our interpretations of our field data examples, we compare our crosshole reflection results with independent information, including borehole logs and surface GPR data.

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