1、 ASCE Manuals and Reports on Engineering Practice No. 118Belowground Pipeline Networks for Utility CablesPrepared bythe Pipeline Planning and Design Committee andthe Underground Pipeline Asset Management Committee ofthe Pipeline Division ofthe American Society of Civil EngineersEdited byLawrence M.
2、Slavin, Ph.D.Library of Congress Cataloging-in-Publication DataBelowground pipeline networks for utility cables / prepared by thePipeline Planning and Design Committee and the Underground PipelineAsset Management Committee of the Pipeline Division of the AmericanSociety of Civil Engineers; edited by
3、 Lawrence M. Slavin.p. cm.(ASCE manuals and reports on engineering practice; no. 118)Includes bibliographical references and index.ISBN 978-0-7844-1055-41. Electric conduits. 2. Underground pipelines. 3. Underground utility lines.4. Underground electric lines. I. Slavin, Lawrence M. II. American Soc
4、iety of Civil Engineers. Pipeline Planning and Design Committee. III. American Society of Civil Engineers. Underground Pipeline Asset Management Committee. IV. Title: Below ground pipelinenetworks for utility cables. TK3261.B45 2009621.31923dc222009025132Published by American Society of Civil Engine
5、ers1801 Alexander Bell DriveReston, Virginia 20191www.pubs.asce.orgAny statements expressed in these materials are those of the individual authors and do not necessarily represent the views of ASCE, which takes no responsibility for any statement made herein. No reference made in this publication to
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11、7844-1055-4Manufactured in the United States of America.16 15 14 13 12 11 10 09 1 2 3 4 5MANUALS AND REPORTS ON ENGINEERING PRACTICE(As developed by the ASCE Technical Procedures Committee, July 1930, and revised March 1935, February 1962, and April 1982)A manual or report in this series consists of
12、 an orderly presentation of facts on a particular subject, supplemented by an analysis of limitations and applications of these facts. It contains information useful to the average engineer in his or her everyday work, rather than fi ndings that may be useful only occasionally or rarely. It is not i
13、n any sense a “stan-dard,” however; nor is it so elementary or so conclusive as to provide a “rule of thumb” for nonengineers.Furthermore, material in this series, in distinction from a paper (which expresses only one persons observations or opinions), is the work of a committee or group selected to
14、 assemble and express information on a specifi c topic. As often as practicable, the committee is under the direction of one or more of the Technical Divisions and Councils, and the product evolved has been subjected to review by the Executive Committee of the Division or Council. As a step in the p
15、rocess of this review, proposed manuscripts are often brought before the members of the Technical Divi-sions and Councils for comment, which may serve as the basis for improvement. When published, each work shows the names of the com-mittees by which it was compiled and indicates clearly the several
16、 pro-cesses through which it has passed in review, in order that its merit may be defi nitely understood.In February 1962 (and revised in April 1982) the Board of Direction voted to establish a series entitled “Manuals and Reports on Engineering Practice,” to include the Manuals published and author
17、ized to date, future Manuals of Professional Practice, and Reports on Engineering Practice. All such Manual or Report material of the Society would have been ref-ereed in a manner approved by the Board Committee on Publications and would be bound, with applicable discussion, in books similar to past
18、 Manuals. Numbering would be consecutive and would be a continuation of present Manual numbers. In some cases of reports of joint committees, bypassing of Journal publications may be authorized.MANUALS AND REPORTS ON ENGINEERING PRACTICE CURRENTLY AVAILABLENo. Title40 Ground Water Management45 Consu
19、lting Engineering: A Guide for the Engagement of Engineering Services49 Urban Planning Guide50 Planning and Design Guidelines for Small Craft Harbors54 Sedimentation Engineering57 Management, Operation and Maintenance of Irrigation and Drainage Systems60 Gravity Sanitary Sewer Design and Constructio
20、n, Second Edition62 Existing Sewer Evaluation and Rehabilitation66 Structural Plastics Selection Manual67 Wind Tunnel Studies of Buildings and Structures68 Aeration: A Wastewater Treatment Process71 Agricultural Salinity Assessment and Management73 Quality in the Constructed Project: A Guide for Own
21、ers, Designers, and Constructors77 Design and Construction of Urban Stormwater Management Systems80 Ship Channel Design81 Guidelines for Cloud Seeding to Augment Precipitation82 Odor Control in Wastewater Treatment Plants84 Mechanical Connections in Wood Structures85 Quality of Ground Water91 Design
22、 of Guyed Electrical Transmission Structures92 Manhole Inspection and Rehabilitation, Second Edition93 Crane Safety on Construction SitesNo. Title94 Inland Navigation: Locks, Dams, and Channels95 Urban Subsurface Drainage97 Hydraulic Modeling: Concepts and Practice98 Conveyance of Residuals from Wat
23、er and Wastewater Treatment100 Groundwater Contamination by Organic Pollutants: Analysis and Remediation101 Underwater Investigations103 Guide to Hiring and Retaining Great Civil Engineers104 Recommended Practice for Fiber-Reinforced Polymer Products for Overhead Utility Line Structures105 Animal Wa
24、ste Containment in Lagoons106 Horizontal Auger Boring Projects107 Ship Channel Design and Operation108 Pipeline Design for Installation by Horizontal Directional Drilling109 Biological Nutrient Removal (BNR) Operation in Wastewater Treatment Plants110 Sedimentation Engineering: Processes, Measuremen
25、ts, Modeling, and Practice111 Reliability-Based Design of Utility Pole Structures112 Pipe Bursting Projects113 Substation Structure Design Guide114 Performance-Based Design of Structural Steel for Fire Conditions115 Pipe Ramming Projects116 Navigation Engineering Practice and Ethical Standards117 In
26、specting Pipeline Inatallation118 Belowground Pipeline Networks for Utility CablesPREFACEThis manual was prepared by the Task Committee on Belowground Pipeline Networks for Utility Cables of the ASCE Pipeline Planning and Design Committee and of the ASCE Underground Pipeline Asset Man-agement Commit
27、tee, in a cooperative effort, under supervision of the Pipeline Division. The manual provides a general overview of methods for placing utility cables belowground, including formal underground conduit systems and relatively low-cost direct-buried facilities, with emphasis on a belowground cable netw
28、ork that represents a cost-effective and space-effi cient installation. The Pipeline Planning and Design Com-mittee, under the leadership of Chairman Sam A. Arnaout, in cooperation with the Underground Pipeline Asset Management Committee, under the leadership of Chairman Thomas D. Iseley, are respon
29、sible for the efforts leading to this publication. The committees would like to thank contribu-tors, task committee members, and reviewers, whose names follow, for their support, time, and effort. The Task Committee chairmen greatly appreciate the support and guidance provided by the U.S. Department
30、 of Transportation and the FHWA TurnerFairbank Highway Research Center.Lawrence M. Slavin, Task Committee ChairOleh Kinash, Task Committee Co-ChairASCE Belowground Pipeline Networks for Utility CablesACKNOWLEDGMENTSCONTRIBUTORSLawrence M. Slavin, Ph.D., ChairOutside Plant Consulting Services, Inc.Ol
31、eh Kinash, Ph.D., Co-ChairIUPUIPurdue School of Engineering proper procedures must be followed on entering such structures. In some cases, controlled environment vaults are used to contain sensitive equipment and hard-ware (Telcordia 1994). Although both communication and electric power 78 BELOWGROU
32、ND PIPELINE NETWORKS FOR UTILITY CABLESsupply cables and equipment may be safely contained within the same structure (IEEE 2007), common practices often deliberately avoid this option. Thus, the bank of conduits within a trench may contain both types of cables,1but the conduits serving communication
33、 facilities would often terminate in separate manholes than those serving electric power.1Communication and power cables must be placed within separate conduits unless they are operated and maintained by the same utility.Figure 2-1. Underground PVC Conduit System (Courtesy of Prime Conduit).Figure 2
34、-2. Underground HDPE Conduit System (Courtesy of A-D Technologies).UNDERGROUND CONDUIT SYSTEMS 9Underground conduit systems may also include other components in addition to the basic array of conduits and typical manholes or vaults suitable for man-entry and access. Smaller structures, such as handh
35、oles (Fig. 2-4), may conveniently be provided in the network for local access to individual ducts or to contain hardware.2.2 DESIGN AND CONSTRUCTION REQUIREMENTSUnderground conduit systems have been in common use for many years, and extensive practices and procedures have evolved to help ensure Figu
36、re 2-3. Telephone Vault (Courtesy of Oldcastle Precast).Figure 2-4. Polymer Concrete Handholes (Courtesy of Quazite, Hubbell Power Systems, Lenoir City).10 BELOWGROUND PIPELINE NETWORKS FOR UTILITY CABLEStheir effi cient and safe design and use. Such practices have been provided by the communication
37、 and power utilities, as well as suppliers of associated products. The basis for many of the current procedures is the original set of Bell System Practices, primarily developed within the telecommunication industry under the auspices of the original American Telephone conduitis a structure containi
38、ng one or more ducts; and conduit system is the com-bination of conduit, conduits, manholes, handholes, and/or vaults joined to form an integrated whole.The NESC adds, “For cables installed in a single duct not part of a conduit system,” the rules for direct-buried cable apply.The rules for each cat
39、egory are provided within separate sections of the NESC document. It is not diffi cult, however, to imagine that there are cases in which the construction details may not clearly fall within either category, and some judgment is required to determine which rules are applicable. Whereas the NESC atte
40、mpts to distinguish between the terms “duct” and “conduit” for its purposes in providing safety rules for the two general modes of belowground construction, this manual uses these terms, as well as “pipe,” interchangeably, with the intent clear from the context.UNDERGROUND CONDUIT SYSTEMS 11The safe
41、ty rules regarding underground conduit systems cover the following areas, including indicated requirements: Location and position:Location of conduit system, such as to avoid being under other parallel networks.Conduit bends of suffi ciently large bend radii to avoid damage to cables to be installed
42、 in ducts (to not exceed allowable bend radii of cables or sidewall bearing pressure under pulling tension).Satisfactory conduit alignment to avoid protrusions that may damage cable.Minimum separation of supply and communication conduit systems, including 3 in. of concrete or 12 in. of earth, unless
43、 the parties agree to lesser separation.Separation of cable conduits from sewer, water, gas, fuel, steam, or other lines to avoid confl icts; conduit shall not enter the same structure (e.g., manhole) as lines transporting fl ammable material (e.g., gas). Excavation and backfi llSatisfactory trench
44、conditions, including smooth trench bottom, absence of large rocks (4 in.) or sharp edges within 6 in. of conduit, and adequate compaction of backfi ll. For ducts and joints:General design and construction of the ducts so as to avoid damage to cables in adjacent ducts in the event of a cable fault i
45、n another duct.Appropriate duct characteristics, including corrosion resistance, absence of sharp internal edges, suffi cient strength to withstand expected loads (e.g., dead, live, equipment, water table, frost heave, or thermal effects).Impact loading added for live loads, but reduced by one-third
46、 per foot of cover (no impact loading required below 3 ft).Duct restraint methods (e.g., concrete, anchors, or backfi ll) suffi -cient to withstand installation, operation, and environmental stresses.Sealing of joints between ducts (resulting in a smooth interior surface for cable installation) and
47、at structure walls (internally and externally to prevent gas entry).Proper support at the entrance to manholes to avoid local shear forces. Manholes, handholes, and vaults:Adequate strength of underground structures, including covers, to withstand expected loads (e.g., dead, live, equipment, water t
48、able, or frost heave); impact loading of 30% added for live loads.12 BELOWGROUND PIPELINE NETWORKS FOR UTILITY CABLESFor roadway areas, ability to withstand live loads of large trucks imposing dual-wheel loads of 16,000 lb over an area of 10 in. 24 in., considering wheel locations resulting in maxim
49、um stress in the structure.For nonvehicular areas, the ability to withstand a live load of 300 lb/ft2minimum.Means of preventing sewer gas from entering (man-entry) struc-tures and provision of adequate ventilation.Cable supports in manholes and vaults designed and mounted to withstand static and live loads, maintain required clearance between cables, provide a 3-in. minimum space above the fl oor (unless otherwise protected), and allow cable movement to relieve stresses.An importa
