scholarly journals Study of a Space-Time Monitoring of High-Speed Railway Underline Structure Using Distributed Optical Vibration Sensing Technology

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Baye Mbaye Diouf ◽  
Ailan Che ◽  
Shaokong Feng
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Interaction Model ◽  
Elastic Field ◽  
Vibration Monitoring ◽  
Railway Track ◽  
High Speed Railway ◽  
Vibration Sensing ◽  
Track Slab ◽  
Optical Vibration

The phenomenon of vibration is quite frequent in various engineering works. Vibration analysis and monitoring occupy a significant place in scientific measurements and engineering applications. The quality of the underline structure actively influences the response of high-speed railway track plate and trackside. Due to years of service and under the action of train loads, bond failure between supporting track plate and cement asphalt mortar layer will imminently occur. And this will significantly influence the vertical dynamic response of a track slab and severely affect the safe operation of the entire railway system which can subsequently lead to a risk of derailment. Firstly, the purpose of the present study is to develop a practical 2D dynamic interaction model of vehicle-track subgrade based on a two-step simulation capable of analyzing the dynamic response of a track slab under different fault distribution in the CA mortar layer by using the commercial software Abaqus. Secondly, the distributed optical vibration sensing (DOVS) technology is discussed and applied on a section of high-speed railway near the Hongqiao station which has been in operation after a long period of degradation for real-time vibration monitoring. Overall, the numerical simulation results show that, in the elastic field, the track plate defects have a significant amplification effect on the vibration, and the magnification can be more than 2 to 3 times. The vibration monitoring results reveal two elements of the fault effects on the track slab dynamic response: the amplification of the dynamic response when the train is arriving and leaving the monitoring section and also causing extreme resonance when the train is passing increasing the vibration signal largely.

scholarly journals Random-Forest Machine Learning Approach for High-Speed Railway Track Slab Deformation Identification Using Track-Side Vibration Monitoring

2021 ◽  
Vol 11 (11) ◽  
pp. 4756
Author(s):  
Gaoran Guo ◽  
Xuhao Cui ◽  
Bowen Du
Keyword(s):  
Random Forest ◽  
High Speed ◽  
Recognition Rate ◽  
Operation Time ◽  
Deformation Monitoring ◽  
Vibration Monitoring ◽  
Railway Track ◽  
Ballastless Track ◽  
Train Operation ◽  
Track Slab

High-speed railways (HSRs) are established all over the world owing to their advantages of high speed, ride comfort, and low vibration and noise. A ballastless track slab is a crucial part of the HSR, and its working condition directly affects the safe operation of the train. With increasing train operation time, track slabs suffer from various defects such as track slab warping and arching as well as interlayer disengagement defect. These defects will eventually lead to the deformation of track slabs and thus jeopardize safe train operation. Therefore, it is important to monitor the condition of ballastless track slabs and identify their defects. This paper proposes a method for monitoring track slab deformation using fiber optic sensing technology and an intelligent method for identifying track slab deformation using the random-forest model. The results show that track-side monitoring can effectively capture the vibration signals caused by train vibration, track slab deformation, noise, and environmental vibration. The proposed intelligent algorithm can identify track slab deformation effectively, and the recognition rate can reach 96.09%. This paper provides new methods for track slab deformation monitoring and intelligent identification.

scholarly journals An Innovative Detection Method of High-Speed Railway Track Slab Supporting Block Plane Based on Point Cloud Data from 3D Scanning Technology

2019 ◽  
Vol 9 (16) ◽  
pp. 3345 ◽  
Author(s):  
Chen ◽  
Qin ◽  
Xia ◽  
Bao ◽  
Huang ◽  
...  
Keyword(s):  
Point Cloud ◽  
High Speed ◽  
Detection Method ◽  
Railway Track ◽  
Point Cloud Data ◽  
3D Scanner ◽  
High Speed Railway ◽  
Cloud Data ◽  
Plane Point ◽  
Track Slab

The dimension detection of high-speed railway track slabs is one of the most important tasks before the track slabs delivery. Based on the characteristics of a 3D scanner which can acquire a large amount of measurement data continuously and rapidly in a short time, this paper uses the integration of 3D scanner and the intelligent robot to detect the CRTSIII (China Railway Track System) track slab supporting block plane, then the dense and accurate supporting block plane point cloud data is obtained, and the point cloud data is registered with the established model. An improved Random Sample Consensus (RANSAC) plane fitting algorithm is also proposed to extract the data of supporting block plane point cloud in this paper. The detection method is verified and the quality analysis of the detection results is assessed by a lot of real point cloud data obtained on site. The results show that the method can meet the quality control of CRTSIII finished track slab and the detection standard. Compared with the traditional detection methods, the detection method proposed in this paper can complete the detection of a track slab in 7 min, which greatly improves the detection efficiency, and has better reliability. The method has wide application prospects in the field of railway component detection.

scholarly journals Experimental and Numerical Investigation on Repairing Effect of Polymer Grouting for Settlement of High-Speed Railway Unballasted Track

2019 ◽  
Vol 9 (21) ◽  
pp. 4496 ◽  
Author(s):  
Hongyuan Fang ◽  
Yingjie Su ◽  
Xueming Du ◽  
Fuming Wang ◽  
Bin Li
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Polymer Materials ◽  
Railway Track ◽  
Fe Model ◽  
Cement Slurry ◽  
High Speed Railway ◽  
Application Range ◽  
Ballastless Track ◽  
Track Slab

Uneven settlement of high-speed railway subgrade leads to the irregularity of high-speed railway line, which seriously affects high-speed train operation. The skylight point of high-speed railway operation is short and the maintenance time is limited. Therefore, how to quickly lift and repair the ballastless track slab in the subsidence section is an urgent problem to be solved in the maintenance of high-speed railways. The two-component non-aqueous reactive polymer material has the advantages of strong expansive force, fast reaction speed, and wide application range, which is extremely suitable for the repair of high-speed railway track slab subsidence and lifting. In this study, the expansion force characteristics of different density polymer materials and the stress-deformation curves at corresponding density are tested in laboratory to propose the mechanical parameters of polymer. Then, a three-dimensional finite element (FE) model of high-speed railway train ballastless-track subgrade is established based on ABAQUS. The mechanical characteristics of CRTS III ballastless track under different repair materials, different elevation, and different density of polymer grouting materials are analyzed. The results show that, under the dynamic load of the train, the stress value of polymer repairing material is less than that of cement slurry, presenting a compressive stress state, which is similar to that of the complete subgrade surface. In addition, within a certain thickness range, increasing the thickness of polymer is beneficial to reducing the difference of stress variation between polymer filling layer and complete pavement. Once beyond this range, the thickness of polymer has little effect on the force variation.

scholarly journals Mechanical Performance of a Ballastless Track System for the Railway Bridges of High-Speed Lines: Experimental and Numerical Study under Thermal Loading

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2876
Author(s):  
Yingying Zhang ◽  
Lingyu Zhou ◽  
Akim D. Mahunon ◽  
Guangchao Zhang ◽  
Xiusheng Peng ◽  
...  
Keyword(s):  
High Speed ◽  
Thermal Loading ◽  
Mechanical Performance ◽  
Track Structure ◽  
Box Girder ◽  
High Speed Railway ◽  
Ballastless Track ◽  
Track System ◽  
Girder Bridge ◽  
Track Slab

The mechanical performance of China Railway Track System type II (CRTS II) ballastless track suitable for High-Speed Railway (HSR) bridges is investigated in this project by testing a one-quarter-scaled three-span specimen under thermal loading. Stress analysis was performed both experimentally and numerically, via finite-element modeling in the latter case. The results showed that strains in the track slab, in the cement-emulsified asphalt (CA) mortar and in the track bed, increased nonlinearly with the temperature increase. In the longitudinal direction, the zero-displacement section between the track slab and the track bed was close to the 1/8L section of the beam, while the zero-displacement section between the track slab and the box girder bridge was close to the 3/8L section. The maximum values of the relative vertical displacement between the track bed and the bridge structure occurred in the section at three-quarters of the span. Numerical analysis showed that the lower the temperature, the larger the tensile stresses occurring in the different layers of the track structure, whereas the higher the temperature, the higher the relative displacement between the track system and the box girder bridge. Consequently, quantifying the stresses in the various components of the track structure resulting from sudden temperature drops and evaluating the relative displacements between the rails and the track bed resulting from high-temperature are helpful in the design of ballastless track structures for high-speed railway lines.

scholarly journals The Design and Implementation of an Inertial GNSS Odometer Integrated Navigation System Based on a Federated Kalman Filter for High-Speed Railway Track Inspection

2021 ◽  
Vol 11 (11) ◽  
pp. 5244
Author(s):  
Xinchun Zhang ◽  
Ximin Cui ◽  
Bo Huang
Keyword(s):  
Kalman Filter ◽  
Navigation System ◽  
High Speed ◽  
Measurement Accuracy ◽  
Railway Track ◽  
Filter Method ◽  
Integrated Navigation ◽  
High Speed Railway ◽  
Track Geometry ◽  
Integrated Navigation System

The detection of track geometry parameters is essential for the safety of high-speed railway operation. To improve the accuracy and efficiency of the state detector of track geometry parameters, in this study we propose an inertial GNSS odometer integrated navigation system based on the federated Kalman, and a corresponding inertial track measurement system was also developed. This paper systematically introduces the construction process for the Kalman filter and data smoothing algorithm based on forward filtering and reverse smoothing. The engineering results show that the measurement accuracy of the track geometry parameters was better than 0.2 mm, and the detection speed was about 3 km/h. Thus, compared with the traditional Kalman filter method, the proposed design improved the measurement accuracy and met the requirements for the detection of geometric parameters of high-speed railway tracks.

Risk Assessment Method for High-Speed Railway Track Based on Dynamically Weighted Acceleration

2021 ◽  
Vol 27 (4) ◽  
pp. 04021030
Author(s):  
Xiaohui Wang ◽  
Jianwei Yang ◽  
Jinhai Wang ◽  
Yanxue Wang ◽  
Fu Liu
Keyword(s):  
Risk Assessment ◽  
High Speed ◽  
Assessment Method ◽  
Railway Track ◽  
High Speed Railway ◽  
Risk Assessment Method

scholarly journals Application of Mastic Asphalt Waterproofing Layer in High-Speed Railway Track in Cold Regions

2018 ◽  
Vol 8 (5) ◽  
pp. 667 ◽  
Author(s):  
Song Liu ◽  
Jun Yang ◽  
Xianhua Chen ◽  
Guotao Yang ◽  
Degou Cai
Keyword(s):  
High Speed ◽  
Railway Track ◽  
High Speed Railway ◽  
Cold Regions ◽  
Mastic Asphalt
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