SIST EN 13848-6:2014

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Železniške naprave - Zgornji ustroj proge - Kakovost tirne geometrije - 6. del: Karakterizacija kakovosti tirne geometrijeBahnanwendungen - Oberbau - Qualität der Gleisgeometrie - Teil 6: Charakterisierung der geometrischen GleislagequalitätApplications ferroviaires - Voie - Qualité géométrique de la voie - Partie 6: Caractérisation de la qualité géométrique de la voieRailway applications - Track - Track geometry quality - Part 6: Characterisation of track geometry quality93.100Gradnja železnicConstruction of railways45.080Rails and railway componentsICS:Ta slovenski standard je istoveten z:EN 13848-6:2014SIST EN 13848-6:2014en,fr,de01-maj-2014SIST EN 13848-6:2014SLOVENSKI
STANDARD



SIST EN 13848-6:2014



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 13848-6
March 2014 ICS 93.100 English Version
Railway applications - Track - Track geometry quality - Part 6: Characterisation of track geometry quality
Applications ferroviaires - Voie - Qualité géométrique de la voie - Partie 6: Caractérisation de la qualité géométrique de la voie
Bahnanwendungen - Oberbau - Qualität der Gleisgeometrie - Teil 6: Charakterisierung der geometrischen Gleislagequalität This European Standard was approved by CEN on 3 February 2014.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
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CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13848-6:2014 ESIST EN 13848-6:2014



EN 13848-6:2014 (E) 2 Contents Page Foreword . 4 1 Scope . 5 2 Normative references . 5 3 Terms, definitions, symbols and abbreviations . 5 3.1 Terms and definitions . 5 3.2 Symbols and abbreviations . 5 4 Basic principles . 6 4.1 Introduction . 6 4.2 Transparency . 6 4.3 Complexity . 7 4.4 Track-vehicle interaction . 7 5 Assessment of track geometry quality: state-of-the-art . 7 5.1 General . 7 5.2 Standard deviation (SD) . 7 5.3 Isolated defects . 8 5.4 Combination of various parameters . 8 5.4.1 Combined standard deviation (CoSD) . 8 5.4.2 Standard deviation of the combinations of parameters . 9 5.4.3 Point mass acceleration method (PMA) . 10 5.5 Methods based on vehicle response . 10 5.5.1 Use of theoretical model . 10 5.5.2 Use of direct measurement . 11 5.6 Power Spectral Density (PSD) . 11 6 Levels of aggregation and calculation methods . 12 7 Classes of track geometry quality . 12 7.1 General . 12 7.2 Description of track quality classes (TQC) . 13 7.3 Values of track quality classes. 14 7.4 Assignment of TQCs . 15 7.5 Possible application of TQCs . 15 Annex A (informative)
Point mass acceleration method (PMA) . 17 A.1 Introduction . 17 A.2 Description of the PMA model . 17 A.3 Calculation of the PMA-assessment figure . 17 A.4 Features of the PMA method . 18 Annex B (informative)
Vehicle Response Analysis methods (VRA) . 19 B.1 Introduction . 19 B.2 Determination of the assessment functions . 19 B.3 Application of the assessment functions . 21 B.4 Features of VRA methods . 23 Annex C (normative)
Method for calculating reference TQIs (TQIref) . 24 C.1 Introduction . 24 C.2 Description of the reference method . 24 SIST EN 13848-6:2014



EN 13848-6:2014 (E)
3 Annex D (informative)
Method of classification of alternative TQI using the TQCs . 26 D.1 Introduction. 26 D.2 Description of the conversion method . 26 Bibliography . 28
SIST EN 13848-6:2014



EN 13848-6:2014 (E) 4 Foreword This document (EN 13848-6:2014) has been prepared by Technical Committee CEN/TC 256 “Railway applications”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2014, and conflicting national standards shall be withdrawn at the latest by September 2014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. This European Standard is one of the series EN 13848 “Railway applications – Track – Track geometry quality” as listed below: — Part 1: Characterisation of track geometry — Part 2: Measuring systems – Track recording vehicles — Part 3: Measuring systems – Track construction and maintenance machines — Part 4: Measuring systems – Manual and lightweight devices — Part 5: Geometric quality levels – Plain line — Part 6: Characterisation of track geometry quality According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 13848-6:2014



EN 13848-6:2014 (E)
5 1 Scope This European Standard characterizes the quality of track geometry based on parameters defined in EN 13848-1 and specifies the different track geometry classes which should be considered. This European Standard covers the following topics: — description of track geometry quality; — classification of track quality according to track geometry parameters; — considerations on how this classification can be used; — this European Standard applies to high-speed and conventional lines of 1 435 mm and wider gauge; — this European Standard forms an integral part of EN 13848 series. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 13848-1, Railway applications - Track - Track geometry quality - Part 1: Characterisation of track geometry 3 Terms, definitions, symbols and abbreviations 3.1 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1.1 re-colouring algorithm which modifies the spectral content of a signal aimed to compensate or apply the characteristics of a specific measuring system Note 1 to entry: The re-colouring is used in EN 13848 series to convert a chord measurement signal into a D1 or D2 measurement signal. 3.1.2 track quality class (TQC) characterization of track geometry quality as a function of speed and expressed as a range of TQIs 3.1.3 track quality index (TQI) value that characterises track geometry quality of a track section based on parameters and measuring methods compliant with EN 13848 series 3.2 Symbols and abbreviations For the purposes of this document, the following symbols and abbreviations apply. SIST EN 13848-6:2014



EN 13848-6:2014 (E) 6 Table 1 — Symbols and abbreviations Symbol Designation Unit AL Alignment mm ATQI Alternative Track Quality Index
CL Cross level mm CoSD Combined standard deviation mm D1 Wavelength range 3 m <
≤ 25 m m D2 Wavelength range 25 m <
≤ 70 m m D3 Wavelength range 70 m <
≤ 150 m for longitudinal level Wavelength range 70 m <
≤ 200 m for alignment m
Wavelength m G Track gauge mm LL Longitudinal level mm MBS Multi Body System
NTQI National Track Quality Index
PMA Point Mass Acceleration (method)
PSD Power Spectral Density m2/(1/m) SD Standard deviation mm SDLL Standard deviation longitudinal level mm SDAL Standard deviation alignment mm TQI Track Quality Index
TQIref Reference Track Quality Index
TQC Track Quality Class
V Speed km/h VRA Vehicle Response Analysis (method)
NOTE In this European Standard, AL stands for “alignment” and is not to be confused with AL standing for “alert limit” as defined in EN 13848–5:2008+A1:2010. 4 Basic principles 4.1 Introduction It is necessary to standardize the way that track geometry quality is assessed in order to permit safe and cost-effective railway traffic by focusing on the functional requirements of both track and vehicle. Basic parameters for track geometry quality assessment As track geometry measurement, vehicles present their outputs in accordance with the parameters specified in EN 13848-1, any standardized assessment method shall be based on these parameters. 4.2 Transparency Any algorithm for track geometry quality assessment complying with this standard shall be fully documented, reproducible and available in the public domain. SIST EN 13848-6:2014



EN 13848-6:2014 (E)
7 4.3 Complexity Track geometry quality should be assessed by as few TQIs as possible and the algorithm should be understandable by the user. 4.4 Track-vehicle interaction Track quality assessment should reflect the principles of track-vehicle interaction. For example, the track geometry defects of the same amplitude but different wavelengths lead to different vehicle responses and the required wavelength range will be different depending on the track-vehicle interaction parameters to be assessed. 5 Assessment of track geometry quality: state-of-the-art 5.1 General Track geometry quality can be characterized by various TQIs according to the level of aggregation they are used for. The TQIs described in the following sub-clauses are used by at least one of the European Railway Networks. They represent the current state-of-the-art of description of track geometry quality. 5.2 Standard deviation (SD) The standard deviation is one of the most commonly used TQIs by European Railway Networks. It represents the dispersion of a signal over a given track section, in relation to the mean value of this signal over the considered section. 1)(12−−=∑=NxxSDNii where N is the number of values in the sample; xi is the current value of a signal; x is the mean value of a signal; SD is the standard deviation. NOTE 1 Standard deviation is linked to the energy of the signal in a given wavelength range [, ] according to the following relationship: ∫=212)(2λλννdSSDxx, where Sxx is the PSD described in 5.6 below. SD is commonly calculated for the following parameters: — Longitudinal level D1; — Alignment D1. It is also calculated for other parameters such as: — Twist; — Track gauge; — Cross level; SIST EN 13848-6:2014



EN 13848-6:2014 (E) 8 — Longitudinal level D2; — Alignment D2. For longitudinal level and alignment it is recommended to calculate SD separately for each rail. It may also be calculated differently (for example: mean of both rails, worst or best of either rail or outer rail in curves). Length of track section used for standard deviation has influence on the result. If comparable results are expected, only one length should be used. Commonly, for maintenance reasons standard deviation is calculated over a length of 200 m. It may be calculated either at fixed distances without overlap or with overlap, as a sliding standard deviation. Calculation of standard deviation is also done over longer distances such as 1 km, an entire line or an entire network. NOTE 2 Distinction between specific track sections, such as plain lines, stations and switches and crossings, can also be made. When calculating SD for twist, track gauge and cross level attention should be paid on the possible influence of the quasi-static part of the signals. 5.3 Isolated defects Isolated defects may present a derailment risk; however counting the number of isolated defects exceeding a specified threshold such as intervention limit and alert limit on a given fixed length of track can be representative of the track geometry quality. This method is used by several European Railway Networks. The number of isolated defects per unit of track length is commonly counted for the following parameters: — Longitudinal level D1; — Alignment D1; — Twist; — Track gauge; — Cross level. It can be also counted for the following parameters: — Longitudinal level D2; — Alignment D2. Commonly, the number of isolated defects is counted over 1 km or more. It may also be counted over 100 m or 200 m of track. If required, distinction between specific track sections can be made, such as plain lines, stations and switches and crossings. Alternatively a calculation can be made to specify what percentage of a line exceeds a certain threshold level. 5.4 Combination of various parameters 5.4.1 Combined standard deviation (CoSD) Assessment of the overall track geometry quality of a track section (200 m, 1 000 m.) can be done by a combination of weighted standard deviations of individual geometric parameters. An example of such a TQI is given below. SIST EN 13848-6:2014



EN 13848-6:2014 (E)
9 2222.LLLLCLCLGGALALSDwSDwSDwSDwCoSD+++= where SD
standard deviation of the individual geometry parameters; w
weighting factor of the individual geometry parameters; with the indices: AL
alignment, average of left and right rails; G
track gauge; CL
cross level; LL
longitudinal level, average of left and right rails. It is up to the Infrastructure Manager to determine the weighting factors, e.g. for tamping purposes the weighting factor wG should be zero. Another method might be to transform the standard deviations of geometry parameters or their combinations into a dimensionless number that can be used without distinction of line category, speed range and track geometry parameter. 5.4.2 Standard deviation of the combinations of parameters Standard deviation for a combination of track geometry parameters can be evaluated. This is based on the observation that the level of the combined signals may better reflect the vehicle behaviour than the individual signals. For example, a standard deviation, over a sliding 200 m length of track, can be evaluated for the sum of alignment and cross level in D1 as follows: — the alignments of left and right rails are combined into one signal, in curves by choosing the outer rail and on tangent track by either averaging or choosing one of the two rails; — cross level and alignment signals are combined together by using a sign convention so that an alignment defect to the right is added with the same sign to a cross level defect where right rail is lower than the left rail. Figure 1 shows an example of the combination of cross level ûz and alignment ywhere the signs are both positive; — the standard deviation of the combined signals is calculated over a sliding 200 m length of track. SIST EN 13848-6:2014



EN 13848-6:2014 (E) 10
Key 1 reference position y = (ALright + ALleft) / 2 combination of alignment ûz = zright - zleft cross level s sum of cross level and alignment Figure 1 — Combination of alignment and cross level 5.4.3 Point mass acceleration method (PMA) The PMA method is based on the following principles: — The PMA model considers an unsprung virtual vehicle. It is assumed to be a point mass, thus only the motion of the centre of gravity is investigated. This point mass is guided in a certain distance over the track centre line. — The point mass is moved at a constant speed corresponding to the maximum allowed speed over the measured track section. — Due to the geometrical imperfection of the track, which is described by the longitudinal level and alignment of both rails, the point mass incurs accelerations ay and az in the horizontal and vertical directions. — The vectorial summation of these accelerations is used to characterize the track geometry quality. Theoretical background information as well as features of the PMA method are given in Annex A. 5.5 Methods based on vehicle response 5.5.1 Use of theoretical model Vehicle response analysis (VRA) can be used to make objective, quantified statements about the relationship between the track geometry quality and the vehicle’s responses at various speeds. It takes into consideration factors such as successions of isolated defects that might generate resonance, combinations of defects at the same location and local track design (e.g. curvature and cant). SIST EN 13848-6:2014



EN 13848-6:2014 (E)
11 The VRA method is based on the following principles: — Calculation of vehicle response to the track geometry measured according to EN 13848-1. The vehicle response being represented by the wheel-rail forces and by accelerations of the vehicle running gear and car body; — Consideration of different vehicle types and speeds, taking into account the worst response of all vehicles considered at every measuring point; — The output can be referred back to single parameters like longitudinal level, twist and alignment; — The assessment criteria take into account the limit values given by EN 14363. When using this method attention should be paid to the consistency between the wavelength domain of the track geometry and the frequency range of the vehicle response parameters. An example of a VRA method as well as features of such methods are given in Annex B. 5.5.2 Use of direct measurement Although not generally used for TQIs calculation, direct measurements of vehicle response can help in assessing interaction between running vehicle and track, with respect to safety as well as ride quality. Usually the accelerations of bogie and car body are measured in both lateral and vertical directions, but measurement of wheel-rail forces, such as lateral and vertical forces (Y and Q), can also be made. Inspection runs are usually made on high speed lines, but they can also be of interest on conventional lines. The following principles should be respected when using direct measurement: — The vehicles used for these evaluations are representative of the rolling stock used on the assessed lines. — The runs are made at the maximum speed of the line, with a tolerance of ± 10 %. — The measurements are made at the parts of the vehicle where the highest response is expected, e.g. the leading bogie or wheelset. — The state of the rail surface (wet or dry) is taken into account. — The position of the train shall be known to be able to locate any defects found. 5.6 Power Spectral Density (PSD) The PSD gives the energy of the signal in relation to frequency for a given track geometry parameter measured over a given track section. For a track geometric parameter x, the most commonly used formula to calculate the PSD is given by: )()(1lim)(ννλνλXXSxx∞→= where
is the wavelength and
the respective spatial frequency; ∫+∞∞−−=λλνπνλdexXi2)()( is the Fourier transformation of x(); SIST EN 13848-6:2014



EN 13848-6:2014 (E) 12 )(νX is the complex conjugate of )(νX. In order to be representative, the PSD should be calculated: — over a sufficient length of track, typically 5 km. However, shorter lengths can also be used by applying Short Time Fourier Transform techniques in order to analyse changes of the spectral characteristics of track geometry; — over a section of track with features and quality as homogeneous as possible, e.g. same track layout or same components; — for a wide range of wavelengths including at least D1 and D2. PSD can be of help for characterizing geometric quality over a section of track or a line for: — vehicle manufacturers to have a better knowledge of the quality of the track the vehicles will run on; — infrastructure managers to know which defect wavelengths are present on the track. One of the main advantages of PSD is that it can show typical peaks corresponding to the existence of repetitive defects such as welds. As there are other methods for calculating PSD, the method used for should be specified. 6 Levels of aggregation and calculation methods Track geometry quality is analysed for a variety of purposes. Different kinds of analysis may be necessary and it is recommended to classify them into different levels of aggregation, according to the expected use of the particular analysis. Hereunder three levels of aggregation of track geometry data are defined: — Detailed level: this level contains the analyses required for deciding local interventions, short term track maintenance and operational restrictions. These analyses can also be of value in case studies by vehicle designers and vehicle-track interaction studies. — Intermediate level: this level contains the analyses used to do medium term track maintenance and renewal planning. This level of aggregation can also be of interest for vehicle design and acceptance procedures. — Overview level: this level contains the analyses required for strategic decisions. A large amount of data are summarized into a few indicators to gain an overview of all or part of a network. These analyses are useful for long term network management by infrastructure managers and national authorities as well as for railway undertakings. Assessment of individual isolated defects as defined in EN 13848-5 is most suitable for characterizing track geometry on a detailed aggregation level. Standard deviation (SD) is most commonly used to describe track geometry quality for intermediate and overview aggregation levels. 7 Classes of track geometry quality 7.1 General Considering their wide use across European Railway Networks and the need to have a single, easily understandable TQI, standard deviation (SD) of longitudinal level and alignment is taken as the reference method to describe track geometry quality. It will be referred to as TQIref in the following. Nevertheless, any other means of description of the track geometry quality can be used, provided that complete documentation is available about the method and how it relates to the reference method. For the purpose of this standard, a survey was conducted to evaluate the European Track Quality in order to establish track quality classes and determine their respective limit values. The survey has been carried out in the D1 SIST EN 13848-6:2014



EN 13848-6:2014 (E)
13 domain according to the method described in Annex C. The track quality data of the participating networks was collected and the cumulative frequency distributions were calculated using a weighted average, according to the network lengths, to achieve European Track Quality distributions for five different speed ranges (V in km/h) which are: — V ≤ 80, — 80 < V ≤ 120, — 120 < V ≤ 160, — 160 < V ≤ 230, — 230 < V ≤ 300. NOTE 1 Speeds higher than 300 km/h were not taken into consideration in the survey because of the lack of representative data. NOTE 2 More details on the track quality survey can be found in the technical report FprCEN/TR 16513. For speeds higher than 160 km/h standard deviations within wavelength D2 (and D3) may also be considered but the corresponding values have not yet been defined. 7.2 Description of track quality classes (TQC) A way to provide an overview of track geometry quality on a track section is a cumulative frequency distribution of the TQIsref as shown in Figure 2. This graph shows the percentage of track length undershooting a given TQIref value on the considered track section. Figure 2 shows the European distribution of LL for the speed range 0 km/h to 80 km/h. For example, in this figure, Y2 % of the concerned track section has a TQIref value that is less than X2.
Key 1 European track quality distribution (aver
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