Railway Cross Research Articles

Blasting vibration effect and safety evaluation method of railway cross tunnels

The evolution characteristics of the peak particle velocity and frequency of an existing railway cross tunnel are systematically studied. The analysis results show that there is a difference in the blasting vibration response before and after the new tunnel face is built. In this paper, a set of blasting vibration response evaluation methods that can quantitatively consider the influence of frequency by means of dimensional analysis is introduced. In addition, relevant knowledge on topics such as wavelet packet analysis, signal processing, structural dynamics, and explosion mechanics is applied to research the influence of the frequency. The research results show that the influence of the frequency on the blasting vibration response can be quantitatively analyzed by quantifying the dynamic amplification factor. To resolve the insufficiency of field monitoring, the distribution of the blasting vibration response along the entire section of the existing tunnel is studied through numerical simulation. Based on the theory of distortion energy in material mechanics, a new idea for evaluating the blasting vibration response of a cross tunnel is proposed.

Detecting geospatial location descriptions in natural language text

ABSTRACT References to geographic locations are common in text data sources including social media and web pages. They take different forms from simple place names to relative expressions that describe location through a spatial relationship to a reference object (e.g. the house beside the Waikato River). Often complex, multi-word phrases are employed (e.g. the road and railway cross at right angles; the road in line with the canal) where spatial relationships are communicated with various parts of speech including prepositions, verbs, adverbs and adjectives. We address the problem of automatically detecting relative geospatial location descriptions, which we define as those that include spatial relation terms referencing geographic objects, and distinguishing them from non-geographical descriptions of location (e.g. the book on the table). We experiment with several methods for automated classification of text expressions, using features for machine learning that include bag of words that detect distinctive words, word embeddings that encode meanings of words and manually identified language patterns that characterise geospatial expressions. Using three data sets created for this study, we find that ensemble and meta-classifier approaches, that variously combine predictions from several other classifiers with data features, provide the best F-measure of 0.90 for detecting geospatial expressions.

Elephant Intrusion Detection and Repulsion System using Matlab

Elephant intrusion across the railway track leads to Human-Elephant conflict, collisionof trains, elephant death and injuries. Railway tracks pass through wild life habitats in several Indian states. In India, due to railway cross lines,the accidents that resulted in the death of249 elephants during 1987-2018.The surveillance and monitoring the elephants in the railway line in the forest is very difficult. The speed of the train in India among forest areas is around 50-55km/h during day and 35km/h at night, the engine driver can’t stop the train once the elephant is seen. So, we develop a system to detect the elephant intrusion at a certain distance by using sensors and image processing using MATLAB, creates an alert to engine driver and forest officer of the region and repel the elephant from the railway line. Hence we are creating a prototype model for real time interaction of elephant intrusion across railway tracks.

New Bridge over the Danube: Vidin–Calafat

The new bridge over the Danube is part of the Pan-European Corridor IV that joins Turkey with Germany. The main feature of this new bridge is that both railway traffic and highway traffic cross the Danube River between Vidin (Bulgaria) and Calafat (Rumania), through this single bridge.It is a precast segmental structure and the main bridge can be divided into two parts: a continuous extradosed structure with spans of 180 m length in the navigable channel and, a continuous bridge with 80 m long span in the non-navigable channel.The main bridge is 31,35 m wide. The cross section of the bridge comprises a single box-girder of 4,50 m depth.Segmental balanced cantilever construction method was chosen for this project. The precast segments were assembled using a launching girder in the non-navigable channel and using a trolley crane in the navigable channel.The key construction methodology elements used in the main bridge are as follows:• Bored piles with a diameter of 2 m were drilled from the Danube River using maritime methods. The maximum pile length is 80 m.• Heavy lifting operations with 240 t capacity for the erection of the extradosed bridge segments.• Vessel impact protection construction comprising 152 heavy lifting operations with precast elements of up to 140 t weight, 10 m length, and 1 m thickness.• Innovative saddles for the extradosed, standard internal prestressing cables in the pylon and couplers for the extradosed stay cables.

Study on Risk Management of Tunnels on Dongguan-Huizhou Intercity Railway

The tunnels on Dongguan-Huizhou intercity railway cross above/underneath existing railways and highways at many positions.These tunnels have shallow covers and weak rock mass in many portions.Furthermore,frequent blasting operations are needed in the tunneling and there are lots of buildings along the railway alignment.In the paper,the risk assessment methods,risk assessment objects and risk control technologies used in the design and construction stages of the tunnels on Dongguan-Huizhou intercity railway are studied by means of analyzing and summarizing the practice of risk management of these tunnels.In the end,the safety risks of these tunnels have been brought under effective control.The paper can provide reference for similar projects in the future.

Ground-dwelling birds near the Qinghai-Tibet highway and railway

The Qinghai-Tibet highway and railway cross desolate habitat at elevations of over 4600 m. We assess specie richness and abundance of ground-dwelling birds using strip transects located at a variety of altitudes perpendicular to this transportation corridor. Bird richness, bird abundance, and abundance of rufous-necked snowfinch, were higher adjacent to the roadway than further way.

Vibrations of a vehicle excited by real road profiles

Based on experimental data obtained from the Lublin III delivery car, we have performed a vibration analysis of the vehicle suspension system. Vertical accelerations on the left and right sides of the suspension system were measured. Experiments were carried out on three types of road surfaces: (a) asphalt, (b) sett, and (c) railway cross. The acceleration signals were examined using Fourier transform, multiscale entropy analysis and continuous wavelet transform. These methods reveal the characteristics of the vibration patterns produced by the various road surface profiles. Our results can be used to assess the efficacy of a vehicle suspension system under different road conditions.

Analysis on the Rupture Failure of Railway Cross Rails

In this paper the failure of two railway cross rails that ruptured during a simulation test under alternating load was investigated. The railway cross rails were made of alloy steel. Visual inspection found that the macrofracture surfaces of the ruptured rails were very flat without macroscopic plastic deformation, and there were conchoidal structures on the fractures that were covered with corrosion products. These are the typical macrofracture characteristics of corrosion fatigue cracking. Tensile and impact tests showed that the mechanical properties of the steel plates met the proper specifications. Optical microscopy found the microstructure of the steel also qualified. Macrofracture analysis revealed that the two ruptures originated at the transitional line from flat plane to camber area on the outer surface of the steel plates. Microfracture observations showed that there were some machining notches near the rupture origins. It was concluded that there was localized stress concentration near the transitional line that was caused by machining notches or the transition structure from the flat plane to camber or by both. The localized stress concentration induced the initiation of a fatigue crack under alternating load, which propagated by corrosion fatigue under alternating load in a humid atmosphere.

Geografska problematika obmejnega naselja Dvori pri Movražu

Naselje Dvori leži v neposredni bližini slovensko-hrvaške meje, nad mejnim prehodom Sočerga in hrvaškim naseljem Mlini. Bližnje oskrbno naselje je 12 km oddaljeno Gračišče, kjer so osnovna šola, ambulanta, krajevni urad, pošta, bencinski servis, dve trgovini in gostilna. Cestna povezava poteka od Gračišča skozi naselji Smokvica in Movraž, nekdanja povezava z Mlini je zaradi državne meje prekinjena, do železniške postaje Rakitovec (železniški mejni prehod na progi proti Puli) pa vodi strma makedamska cesta. Od Kopra so Dvori oddaljeni več kot 20 km, zato so bili v preteklosti bolj povezani z bližjim Buzetom. Razmere so se v marsičem spremenile, kar pa ni le posledica nastanka meje, ampak predvsem socialnih sprememb. Nekdaj je bilo kmetijstvo, kljub manj ugodnim pogojem, glavni vir dohodka prebivalcev, danes pa obsežne pašne površine in senožeti prerašča gospodarsko nepomemben gozd. Za naselje je poleg stalnega upadanja števila prebivalcev značilna tudi prevlada ostarelih gospodinjstev, ki so brez naslednikov. Nastanek državne meje in s tem obmejna lega za življenje prebivalcev nista imela večjih negativnih posledic. Prekomejno lastništvo se tu pojavlja v zelo majhnem obsegu in zadeva le hrvaške prebivalce, zaposlovanje na hrvaški strani meje je bilo izjema že pred letom 1991, sorodstvene vezi pa so se kljub nastanku meje ohranile.

An evaluation of six configurations of the railway cross buck sign

Two experimental versions of the X-shaped railway crossbuck sign (white with red border, and yellow with black border) and the Canadian standard were compared in a series of four experiments. The angular separation between the blades of the sign was varied (45° and 90°) and all signs were tested against both a grass-green and a sky-blue background. Standard Canadian regulatory and warning signs were used as distractor stimuli in all experiments. Laboratory measures of classification time, glance legibility, and legibility distance indicated the experimental versions to be generally superior to the existing standard. Legibility distance was greater for signs with blades separated by 90° than for those with 45° angles. A final experiment revealed initial comprehension or the red and white crossbuck to be better than that for the yellow and black version.