scholarly journals Development of Condition Assessment Index of Ballast Track Using Ground-Penetrating Radar (GPR)

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6875
Author(s):  
Fiseha Nega Birhane ◽  
Yeong Tae Choi ◽  
Sung Jin Lee
Keyword(s):  
Ground Penetrating Radar ◽  
Critical Factor ◽  
Analysis Method ◽  
Worst Case ◽  
Assessment Index ◽  
Fouled Ballast ◽  
Ballast Track ◽  
Maintenance Requirements ◽  
Ground Penetrating ◽  
Track Irregularities

The condition of the ballast is a critical factor affecting the riding quality and the performance of a track. Fouled ballast can accelerate track irregularities, which results in frequent ballast maintenance requirements. Severe fouling of the ballast can lead to track instability, an uncomfortable ride and, in the worst case, a derailment. In this regard, maintenance engineers perform routine track inspections to assess current and future ballast conditions. GPR has been used to assess the thickness and fouling levels of ballast. However, there are no potent procedures or specifications with which to determine the level of fouling. This research aims to develop a GPR analysis method capable of evaluating ballast fouling levels. Four ballast boxes were constructed with various levels of fouling. GPR testing was conducted using a GSSI (Geophysical Survey Systems, Inc.) device (400, 900, 1600 MHz), and a KRRI (Korea Railroad Research Institute) GPR device (500 MHz), which was developed for ballast tracks. The dielectric permittivity, scattering of the depth (thickness) values, signal strength at the ballast boundary, and area of the frequency spectrum were compared against the fouling level. The results show that as the fouling level increases, the former two variables increase while the latter two decrease. On the basis of these observations, a new integrated parameter, called a ballast condition scoring index (BCSI), is suggested. The BCSI was verified using field data. The results show that the BCSI has a strong correlation with the fouling level of the ballast and can be used as a fouling-level-indicating parameter.

Analysis Method for Studying Groundwater under a Church

2016 ◽  
Vol 861 ◽  
pp. 263-270
Author(s):  
M. Eugenia Torner ◽  
Ángeles Mas ◽  
Carlos Lerma ◽  
Enrique Gil ◽  
Jose Vercher ◽  
...  
Keyword(s):  
Seventeenth Century ◽  
Ground Penetrating Radar ◽  
Research Work ◽  
Three Dimensional ◽  
Analysis Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Ground Penetrating ◽  
The Church ◽  
Main Entrance

The Church of Asunción of Llíria (Valencia, Spain) is one of the best examples of the Valencian Baroque of the seventeenth century. This research is based on the study of the building from an urban, historical, and especially, a constructive view. The location of this particular church is unique because it is embedded in a mountain. First, some excavations were made into the mountain before the construction of the church started. Thus, there is a slope between the main entrance of the church and the rear. This research work provides the analysis of the ground humidity throughout the Ground Penetrating Radar (GPR) technique. We have analysed the subsoil of the whole church by various cuts or paths. Longitudinal and transversal measurements allowed us to produce a three-dimensional model of the land on which the church stands. We have also analysed the homogeneity or heterogeneity of the subsoil in each area and the presence of certain ground water routes. The rising moisture has been analysed on the walls and pillars of the church. To this end, a moisture analyser has been employed to monitor the moisture content over a period of six months. With this information, it was possible to identify points that are systematically more humid.

An Evaluation of Fouled Ballast in a Laboratory Model Track Using Ground Penetrating Radar

2010 ◽  
Vol 33 (5) ◽  
pp. 103045 ◽  
Author(s):  
L. D. Suits ◽  
T. C. Sheahan ◽  
Li-Jun Su ◽  
Cholachat Rujikiatkamjorn ◽  
Buddhima Indraratna
Keyword(s):  
Ground Penetrating Radar ◽  
Laboratory Model ◽  
Fouled Ballast ◽  
Ground Penetrating

Model track studies on fouled ballast using ground penetrating radar and multichannel analysis of surface wave

2011 ◽  
Vol 74 (4) ◽  
pp. 175-184 ◽  
Author(s):  
P. Anbazhagan ◽  
Su Lijun ◽  
Indraratna Buddhima ◽  
Rujikiatkamjorn Cholachat
Keyword(s):  
Surface Wave ◽  
Ground Penetrating Radar ◽  
Fouled Ballast ◽  
Multichannel Analysis ◽  
Ground Penetrating

scholarly journals Application of Ground-Penetrating Radar Broadband Antenna in Underground Detection

2020 ◽  
Vol 198 ◽  
pp. 04005
Author(s):  
Zhang Chengke ◽  
Yu Junping ◽  
Wu Jiangpeng ◽  
Li Zhiqiang ◽  
Zhu Liqing
Keyword(s):  
Antenna Array ◽  
Ground Penetrating Radar ◽  
Electromagnetic Properties ◽  
Detection Accuracy ◽  
Analysis Method ◽  
Broadband Antenna ◽  
Working Frequency ◽  
Design Characteristics ◽  
Electromagnetic Signals ◽  
Ground Penetrating

When GPR is detecting unknown objects underground, different antenna working frequency, different antenna size and different antenna internal structure will affect the final data quality and ultimately affect the detection accuracy of GPR. Therefore, when actualizing and evaluating the uwb signal of GPR electromagnetic wave, the electromagnetic properties of underground medium should be fully considered, and the influence of relevant parameters of GPR antenna on the transmitted and received electromagnetic signals should be analyzed by using numerical analysis method. This paper mainly describes the design characteristics of GPR antenna and antenna array, as well as the types, characteristics and application convenience of antenna array under different positioning purposes of GPR.

REFLECTION COEFFICIENT OF AN ELECTROMAGNETIC WAVE IN CONDUCTIVE MEDIA

2018 ◽  
pp. 100-106
Author(s):  
M. S. Sudakova ◽  
M. L. Vladov ◽  
M. R. Sadurtdinov
Keyword(s):  
Reflection Coefficient ◽  
Ground Penetrating Radar ◽  
Electromagnetic Waves ◽  
Water Contamination ◽  
Survey Design ◽  
Direct And Inverse Problems ◽  
The Difference ◽  
Ground Penetrating ◽  
Ideal Dielectric

Within the ground penetrating radar bandwidth the medium is considered to be an ideal dielectric, which is not always true. Electromagnetic waves reflection coefficient conductivity dependence showed a significant role of the difference in conductivity in reflection strength. It was confirmed by physical modeling. Conductivity of geological media should be taken into account when solving direct and inverse problems, survey design planning, etc. Ground penetrating radar can be used to solve the problem of mapping of halocline or determine water contamination.

Deteksi Bentuk Objek Bawah Tanah Menggunakan Pengolahan Citra B-Scan pada Ground Penetrating Radar (GPR)

2017 ◽  
Vol 3 (1) ◽  
pp. 73-83
Author(s):  
Rahmayati Alindra ◽  
Heroe Wijanto ◽  
Koredianto Usman
Keyword(s):  
Signal Processing ◽  
Ground Penetrating Radar ◽  
Post Processing ◽  
Data Survey ◽  
Ground Penetrating

Ground Penetrating Radar (GPR) adalah salah satu jenis radar yang digunakan untuk menyelidiki kondisi di bawah permukaan tanah tanpa harus menggali dan merusak tanah. Sistem GPR terdiri atas pengirim (transmitter), yaitu antena yang terhubung ke generator sinyal dan bagian penerima (receiver), yaitu antena yang terhubung ke LNA dan ADC yang kemudian terhubung ke unit pengolahan data hasil survey serta display sebagai tampilan output-nya dan post  processing untuk alat bantu mendapatkan informasi mengenai suatu objek. GPR bekerja dengan cara memancarkan gelombang elektromagnetik ke dalam tanah dan menerima sinyal yang dipantulkan oleh objek-objek di bawah permukaan tanah. Sinyal yang diterima kemudian diolah pada bagian signal processing dengan tujuan untuk menghasilkan gambaran kondisi di bawah permukaan tanah yang dapat dengan mudah dibaca dan diinterpretasikan oleh user. Signal processing sendiri terdiri dari beberapa tahap yaitu A-Scan yang meliputi perbaikan sinyal dan pendektesian objek satu dimensi, B-Scan untuk pemrosesan data dua dimensi  dan C-Scan untuk pemrosesan data tiga dimensi. Metode yang digunakan pada pemrosesan B-Scan salah satunya adalah dengan  teknik pemrosesan citra. Dengan pemrosesan citra, data survey B-scan diolah untuk didapatkan informasi mengenai objek. Pada penelitian ini, diterapkan teori gradien garis pada pemrosesan citra B-scan untuk menentukan bentuk dua dimensi dari objek bawah tanah yaitu persegi, segitiga atau lingkaran. 

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