Analysis on the track quality evolution law of polyurethane-reinforced ballasted track in high-speed railway

2020 ◽  
pp. 095440972097557
Author(s):  
Jie-Ling Xiao ◽  
Pu Jing ◽  
Si-Xin Yu ◽  
Ping Wang
Keyword(s):  
Standard Deviation ◽  
Test Section ◽  
High Speed ◽  
Ride Comfort ◽  
Normal Operation ◽  
High Speed Railway ◽  
Evolution Law ◽  
Ballasted Track ◽  
One Year ◽  
Track Quality

Polyurethane-reinforced ballasted track (PRBT) can improve the integrity of ballasted track structures and satisfy the high-stability requirements of high-speed railways. In this study, the quality evolution law of PRBT structures after being launched into train service was analyzed, and a reference for structural optimization and maintenance operation was provided. The track geometric state of the PRBT test section of a high-speed railway was measured and monitored for nearly one year after it was launched into operation, and the ballastless track of the adjacent section was selected as a reference. The geometric states of the tracks were evaluated and compared using various parameters, including sliding standard deviation, average standard deviation, and track irregularity spectrum density. Results show that the track quality indexes of the test section, which were in operation for nearly one year, were slightly over the limit. Moreover, the fastener can be finely adjusted for the high-value index sections to further improve the ride comfort. The application effect of PRBT in the subgrade fracture zone was good, which could satisfy the requirements of high-quality transportation as well as the normal operation and maintenance of high-speed railway.

scholarly journals Improvement and In-Situ Application of an Evaluation Method of Ballasted-Track Condition Using Digital 2-D Image Analysis

2020 ◽  
Vol 10 (21) ◽  
pp. 7946
Author(s):  
Bongsik Park ◽  
Yeong-Tae Choi ◽  
Hyunmin Kim
Keyword(s):  
Image Analysis ◽  
High Speed ◽  
Evaluation Method ◽  
Recognition Rate ◽  
High Speed Railway ◽  
Analysis Methods ◽  
Track Condition ◽  
Ballasted Track ◽  
Track Irregularity

The advancement in digital image analysis methods has led to the development of various techniques, i.e., quantification of ballast gravel abrasion. In this study, the recognition rate of gravel aggregates has been significantly increased by improving the image analysis methods. The correlation between the track quality index (TQI), which is the standard deviation of vertical track irregularity and represents the condition of a high-speed railway, and the number of maintenance works was analyzed by performing an image analysis on the samples collected from various locations of a high-speed railway. The results revealed that roundness has the highest correlation with the TQI, whereas sphericity has the highest correlation with the number of maintenance works. The ballast replacement would be performed to improve maintenance efficiency if the abrasion of the ballast aggregates becomes approximately 10%.

scholarly journals Dynamic variation characteristics of layered monitored land subsidence near a fast railway line

2020 ◽  
Vol 382 ◽  
pp. 339-344
Author(s):  
Kaiwen Shi ◽  
Yong Luo
Keyword(s):  
Land Subsidence ◽  
High Speed ◽  
Normal Operation ◽  
High Speed Railway ◽  
Railway Line ◽  
Plain Area ◽  
Subsidence Area ◽  
Deformation Law ◽  
Variation Characteristics ◽  
Railway Passenger

Abstract. The fast railway line B is a high-speed railway passenger passageway in Beijing, with a total length of 40.75 km. In the plain area, the railway passes through the land subsidence area of Beijing from south to north, which poses a certain threat to the normal operation of a high-speed railway. Using layered monitoring data for the period 2009–2014 from station A, this paper analyses dynamic changes in the annual subsidence rate and the rate and percentage of soil deformation at different depths, as well as the compression deformation law of soil with different lithology and depth with the change of the water level. The results show that (1) since 2012, the proportion of shallow-layer (≤82 m) compression and settlement contribution has gradually decreased, while the proportion of deep-layer (> 82 m) compression has significantly increased; (2) during the deformation process of layered soil, the amount of compression is closely related to the change of groundwater level; and (3) the shallow, middle and deep strata show obvious viscoelastic–plastic deformation characteristics on the whole.

scholarly journals Assessments of land subsidence along Rizhao-Lankao High-speed Railway at Heze, China between 2015 and 2019 with Sentinel-1 data

2020 ◽  
Author(s):  
Chuanguang Zhu ◽  
Wenhao Wu ◽  
Mahdi Motagh ◽  
Liya Zhang ◽  
Zongli Jiang ◽  
...  
Keyword(s):  
Land Subsidence ◽  
High Speed ◽  
Underground Mining ◽  
Ground Deformation ◽  
Ground Subsidence ◽  
Normal Operation ◽  
Monthly Precipitation ◽  
High Speed Railway ◽  
Subsidence Area ◽  
Under Construction

Abstract. The Heze section of Rizhao-Lankao High-speed Railway (RLHR-HZ) has been under construction since 2018 and will be operative by the end of 2021. However, there is a concern that land subsidence in Heze region may affect the normal operation of RLHR-HZ. In this study, we investigate the contemporary ground deformation in the region between 2015 and 2019 by using more than 350 C-band interferograms constructed from two tracks of Sentine-1 data over the region. The Small Baselines Subset (SBAS) technique is adopted to compile the time series displacement. We find that the RLHR-HZ runs through two main subsidence areas: One is located east of Heze region with rates ranging from −4 cm/yr to −1 cm/yr, and another one is located in the coal field with rates ranging from −8 cm/yr to −2 cm/yr. A total length of 35 km of RLSR-HZ are affected by the two subsidence basins. Considering the previous investigation and the monthly precipitation, we infer that the subsidence bowl east of Heze region is due to massive extraction of deep groundwater. Close inspections of the relative locations between the second subsidence area and the underground mining reveals that the subsidence there is probably caused by the groundwater outflow and fault instability due to mining, rather than being directly caused by mining. The InSAR-derived ground subsidence implies that it's necessary to continue monitoring the ground deformation along RLSR-HZ.

scholarly journals Analysis of Mobile Phone Data to Compare Mobility Flows and Hotspots Before and After the Opening of High-Speed Railway: Case Study of Honam KTX in Korea

2020 ◽  
Vol 10 (14) ◽  
pp. 5009
Author(s):  
Jin Ki Eom ◽  
Kwang-Sub Lee ◽  
Ji Young Song ◽  
Jun Lee
Keyword(s):  
Mobile Phone ◽  
High Speed ◽  
Mobile Phone Data ◽  
High Speed Railway ◽  
Railway Stations ◽  
Intercity Travel ◽  
Before And After ◽  
Transit Agencies ◽  
One Year ◽  
The Impact

Mobile phone data provides information, such as the home (origin) and current locations of people. The data can be used to analyze the impact of new high-speed railway (HSR) openings. This study examined the population observed in stations and cities of the Honam HSR line in Korea, based on mobile phone data recorded one year before and after its opening. We analyzed the volume of the population observed at each railway station, density of the distance between home and station, and activity hotspots in a city. The results show that the number of people and travel distance increased after the opening of the HSR. The distance to access railway stations increased, as the HSR saves travel time. Moreover, the activity hotspots in a city increased after the opening of the HSR, as more people gathered near the station area. The findings show that the mobility measures enhanced after the opening of the HSR for regional travel and local activities. These measures can help transit agencies and planners in providing better intercity travel.

Influence of Conversion Deviation on Dynamic Performance of High-Speed Railway Turnout

2011 ◽  
Vol 474-476 ◽  
pp. 1599-1604 ◽  
Author(s):  
Rong Chen ◽  
Wang Ping ◽  
Xian Kui Wei
Keyword(s):  
High Speed ◽  
Detection System ◽  
Structural Characteristics ◽  
Dynamic Responses ◽  
Normal Operation ◽  
Foreign Matter ◽  
Wheel Load ◽  
High Speed Railway ◽  
Lateral Displacements ◽  
Railway Turnout

Railway turnout, an integrated mechatronics equipment of track technology, is one of key equipments that control the running speed of high-speed railway. During the conversion of turnout, the friction, inclusion of foreign matter and deficient displacement of conversion caused by its own structural characteristics may lead to severe wheel/rail impact. In order to study the influence of conversion deviation on safety and comfort of a train during passing the turnout, train/turnout dynamic model was applied. Taking No.18 turnout on a Passenger Dedicated Line (PDL) with 350km/h as a case study, when the train passed it, the influences of its deficient displacement and inclusion of foreign matter on the following dynamic responses were studied, i.e. wheel load distribution, wheel flange force, dynamic stress of rail, wheel unloading rate, derailment coefficient, as well as the lateral displacements of switch rail and nose rail, etc. Result shows that: (1) the deficient displacement and the inclusion of foreign matter will severely influence the normal operation of the turnout, so the safety and comfort during the train passing through turnout may be affected; (2) During the conversion of turnout, its deficient displacement should be controlled properly, and the foreign matter should be removed during routine maintenance, moreover, a reliable detection system should be set.

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