1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T L.10 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (08/2015) SERIES L: ENVIRONMENT AND ICTS, CLIMATE CHANGE, E-WASTE, ENERGY EFFICIENCY; CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PL
2、ANT Optical fibre cables for duct and tunnel application Recommendation ITU-T L.10 Rec. ITU-T L.10 (08/2015) i Recommendation ITU-T L.10 Optical fibre cables for duct and tunnel application Summary Recommendation ITU-T L.10 describes characteristics, construction and test methods of optical fibre ca
3、bles for duct and tunnel application. First, in order that an optical fibre demonstrates sufficient performance, characteristics that a cable should possess are described. Then, the method of examining whether a cable has the required characteristics is described. Required conditions may differ acco
4、rding to installation environment. Therefore, detailed conditions of experiments need to be agreed upon between user and supplier on the basis of the environment where a cable is used. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T L.10 1988-11-25 11.1002/1000/1414 2.0 ITU-
5、T L.10 2002-12-22 6 11.1002/1000/6134 3.0 ITU-T L.10 2015-08-13 15 11.1002/1000/12532 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii
6、Rec. ITU-T L.10 (08/2015) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU
7、-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for stu
8、dy by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a
9、collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain
10、certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express req
11、uirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Rig
12、ht. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intelle
13、ctual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2015 All right
14、s reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T L.10 (08/2015) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 3 3.1 Terms defined elsewhere 3 3.2 Terms defined in this Recommendation .
15、3 4 Abbreviations and acronyms 3 5 Conventions 3 6 Characteristics of optical fibres and cables 3 6.1 Optical fibre characteristics 3 6.2 Mechanical characteristics 4 6.3 Environmental conditions . 4 6.4 Fire safety . 6 7 Cable construction 6 7.1 Fibre coatings . 6 7.2 Cable elements 7 7.3 Sheath .
16、9 7.4 Armour . 9 7.5 Identification of cable . 10 7.6 Cable sealing 10 7.7 Considerations for duct installation 10 8 Test methods . 10 8.1 Test methods for cable elements 10 8.2 Test methods for mechanical characteristics of the cable 11 8.3 Test methods for environmental characteristics . 12 Biblio
17、graphy. 15 Rec. ITU-T L.10 (08/2015) 1 Recommendation ITU-T L.10 Optical fibre cables for duct and tunnel application 1 Scope This Recommendation: refers to multi-mode graded index and single-mode optical fibre cables to be used for telecommunication networks in ducts and tunnels; deals with mechani
18、cal and environmental characteristics of the concerned optical fibre cables. The optical fibre dimensional and transmission characteristics, together with their test methods, should comply with one or more of ITU-T G.651.1, ITU-T G.652, ITU-T G.653, ITU-T G.654, ITU-T G.655, ITU-T G.656 and ITU-T G.
19、657; deals with fundamental considerations related to optical fibre cable from the mechanical and environmental points of view. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation
20、. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references list
21、ed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.650.1 Recommendation ITU-T G.650.1 (2010), Definitions and test methods fo
22、r linear, deterministic attributes of single-mode fibre and cable. ITU-T G.650.2 Recommendation ITU-T G.650.2 (2007), Definitions and test methods for statistical and non-linear related attributes of single-mode fibre and cable. ITU-T G.650.3 Recommendation ITU-T G.650.3 (2008), Test methods for ins
23、talled single-mode optical fibre cable links. ITU-T G.651.1 Recommendation ITU-T G.651.1 (2007), Characteristics of a 50/125 m multimode graded index optical fibre cable for the optical access network. ITU-T G.652 Recommendation ITU-T G.652 (2009), Characteristics of a single-mode optical fibre and
24、cable. ITU-T G.653 Recommendation ITU-T G.653 (2010), Characteristics of a dispersion-shifted single-mode optical fibre and cable. ITU-T G.654 Recommendation ITU-T G.654 (2012), Characteristics of a cut-off shifted single-mode optical fibre and cable. ITU-T G.655 Recommendation ITU-T G.655 (2009), C
25、haracteristics of a non-zero dispersion-shifted single-mode optical fibre and cable. ITU-T G.656 Recommendation ITU-T G.656 (2010), Characteristics of a fibre and cable with non-zero dispersion for wideband optical transport. ITU-T G.657 Recommendation ITU-T G.657 (2012), Characteristics of a bendin
26、g-loss insensitive single-mode optical fibre and cable for the access network. ITU-T K.29 Recommendation ITU-T K.29 (1992), Coordinated protection schemes for telecommunication cables below ground. 2 Rec. ITU-T L.10 (08/2015) ITU-T K.47 Recommendation ITU-T K.47 (2012), Protection of telecommunicati
27、on lines against direct lightning flashes. ITU-T L.1 Recommendation ITU-T L.1 (1988), Construction, installation and protection of telecommunication cables in public networks. ITU-T L.27 Recommendation ITU-T L.27 (1996), Method for estimating the concentration of hydrogen in optical fibre cables. IT
28、U-T L.46 Recommendation ITU-T L.46 (2000), Protection of telecommunication cables and plant from biological attack. IEC 60331-25 IEC 60331-25 (1999), Tests for electric cables under fire conditions Circuit integrity Part 25: Procedures and requirements Optical fibre cables. IEC 60332-1-2 IEC 60332-1
29、-2 (2004), Tests on electric and optical fibre cables under fire conditions Part 1-2: Test for vertical flame propagation for a single insulated wire or cable Procedure for 1 kW pre-mixed flame. IEC 60332-3-24 IEC 60332-3-24 (2000), Tests on electric and optical fibre cables under fire conditions Pa
30、rt 3-24: Test for vertical flame spread of vertically-mounted bunched wires or cables Category C. IEC 60754-1 IEC 60754-1 (2011), Test on gases evolved during combustion of materials from cables Part 1: Determination of the halogen acid gas content. IEC 60754-2 IEC 60754-2 (2011), Test on gases evol
31、ved during combustion of materials from cables Part 2: Determination of acidity (by pH measurement) and conductivity. IEC 60793-1-1 IEC 60793-1-1 (2008), Optical fibres Part 1-1: Measurement methods and test procedures General and guidance. IEC 60793-1-21 IEC 60793-1-21 (2001), Optical fibres Part 1
32、-21: Measurement methods and test procedures Coating geometry. IEC 60793-1-32 IEC 60793-1-32 (2010), Optical fibres Part 1-32: Measurement methods and test procedures Coating strippability. IEC 60793-2-10 IEC 60793-2-10 (2011), Optical fibres Part 2-10: Product specifications Sectional specification
33、 for category A1 multimode fibres. IEC 60793-2-50 IEC 60793-2-50 (2012), Optical fibres Part 2-50: Product specifications Sectional specification for class B single-mode fibres. IEC 60794-1-1 IEC 60794-1-1(2011), Optical fibre cables Part 1-1: Generic specification General. IEC 60794-1-2 IEC 60794-1
34、-2 (2013), Optical fibre cables Part 1-2: Generic specification Cross references table for optical cable test procedures. IEC 60794-1-21 IEC 60794-1-21 (2015), Optical fibre cables Part 1-21: Generic specification Basic optical cable test procedures Mechanical tests methods. IEC 60794-1-22 IEC 60794
35、-1-22 (2012), Optical fibre cables Part 1-22: Generic specification Basic optical cable test procedures Environmental tests methods. Rec. ITU-T L.10 (08/2015) 3 IEC 60794-1-23 IEC 60794-1-23 (2012), Optical fibre cables Part 1-23: Generic specification Basic optical cable test procedures Cable eleme
36、nt test methods. IEC 60794-3 IEC 60794-3 (2014), Optical fibre cables Part 3: Outdoor cables Sectional specification. IEC 60811-202 IEC 60811-202 (2012), Electric and optical fibre cables Test methods for non-metallic materials Part 202: General tests Measurement of thickness of non-metallic sheath.
37、 IEC 60811-203 IEC 60811-203 (2012), Electric and optical fibre cables Test methods for non-metallic materials Part 203: General tests Measurement of overall dimensions. IEC 61034-1 IEC 61034-1 (2005), Measurement of smoke density of cables burning under defined conditions Part 1: Test apparatus. IE
38、C 61034-2 IEC 61034-2 (2005), Measurement of smoke density of cables burning under defined conditions Part 2: Test procedure and requirements. 3 Definitions 3.1 Terms defined elsewhere For the purpose of this Recommendation, the definitions given in ITU-T G.650.1, ITU-T G.650.2, ITU-T G.650.3 and IT
39、U-T G.651.1 apply. 3.2 Terms defined in this Recommendation None. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: SZ Reverse oscillating stranding 5 Conventions None. 6 Characteristics of optical fibres and cables 6.1 Optical fibre characteristics Opti
40、cal fibres should be used as described in ITU-T G.651.1, ITU-T G.652, ITU-T G.653, ITU-T G.654, ITU-T G.655, ITU-T G.656 or ITU-T G.657. 6.1.1 Transmission characteristics The typical transmission characteristics are described for each optical fibre in its respective Recommendation. Unless specified
41、 otherwise by the users of the Recommendations, those values apply to the corresponding cabled optical fibre. 6.1.2 Fibre microbending Severe bending of an optical fibre involving local axial displacement of a few micrometres over short distances caused by localized lateral forces along its length i
42、s called microbending. This may be 4 Rec. ITU-T L.10 (08/2015) caused by manufacturing and installation strains, and also by dimensional variations of cable materials due to temperature changes during operation. Microbending can cause an increase in optical loss. In order to reduce microbending loss
43、, stress randomly applied to a fibre along its axis should be eliminated during the incorporation of the fibres into the cable, as well as during and after cable installation. 6.1.3 Fibre macrobending Macrobending is the resulting curvature of an optical fibre after cable manufacture and installatio
44、n. Macrobending can cause an increase in optical loss. The optical loss increases if the bending radius is too small. NOTE ITU-T G.657 optical fibres are optimized for reduced macrobending loss. 6.2 Mechanical characteristics 6.2.1 Bending Under the dynamic conditions encountered during installation
45、, the fibre is subjected to strain from both cable tension and bending. The strength elements in the cable and the installation bend radius must be selected to limit this combined dynamic strain. Any fibre bend radius remaining after cable installation shall be large enough to limit the macrobending
46、 loss or long-term strain limiting the lifetime of the fibre. 6.2.2 Tensile strength Optical fibre cable is subjected to short-term loading during manufacture and installation, and may be affected by continuous static loading and/or cyclic loading during operation (e.g., temperature variation). Chan
47、ges in the tension of the cable due to the variety of factors encountered during the service life of the cable can cause the differential movement of the cable components. This effect needs to be considered in the cable design. Excessive cable tensile loading increases the optical loss and may cause
48、 increased residual strain in the fibre if the cable cannot relax. To avoid this, the maximum tensile strength determined by the cable construction, especially the design of the strength member, should not be exceeded. NOTE Where a cable is subjected to permanent loading during its operational life,
49、 the fibre should preferably not experience additional strain. 6.2.3 Crush and impact The cable may be subjected to crush and impact both during installation and operational life. Crush and impact may increase the optical loss (permanently, or for the period of time during the application of the stress) and excessive stress may lead to fibre fracture. 6.2
