1、Designation: D 2321 05An American National StandardStandard Practice forUnderground Installation of Thermoplastic Pipe for Sewersand Other Gravity-Flow Applications1This standard is issued under the fixed designation D 2321; the number immediately following the designation indicates the year oforigi
2、nal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of De
3、fense.1. Scope1.1 This practice provides recommendations for the instal-lation of buried thermoplastic pipe used in sewers and othergravity-flow applications. These recommendations are in-tended to ensure a stable underground environment for ther-moplastic pipe under a wide range of service conditio
4、ns.However, because of the numerous flexible plastic pipe prod-ucts available and the inherent variability of natural groundconditions, achieving satisfactory performance of any oneproduct may require modification to provisions containedherein to meet specific project requirements.1.2 The scope of t
5、his practice necessarily excludes productperformance criteria such as minimum pipe stiffness, maxi-mum service deflection, or long term strength. Thus, it isincumbent upon the product manufacturer, specifier, or projectengineer to verify and assure that the pipe specified for anintended application,
6、 when installed according to proceduresoutlined in this practice, will provide a long term, satisfactoryperformance according to criteria established for that applica-tion. A commentary on factors important in achieving asatisfactory installation is included in Appendix X1.NOTE 1Specific paragraphs
7、in the appendix are referenced in thebody of this practice for informational purposes.NOTE 2The following ASTM standards may be found useful inconnection with this practice: Practice D 420, Test Method D 1556,Method D 2216, Specification D 2235, Test Method D 2412, SpecificationD 2564, Practice D 26
8、57, Practice D 2855, Test Methods D 2922, TestMethod D 3017, Practice F 402, Specification F 477, Specification F 545,and Specification F 913.NOTE 3Most Plumbing Codes and some Building Codes have provi-sions for the installation of underground “building drains and buildingsewers.” See them for plum
9、bing piping applications.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations pri
10、or to use.2. Referenced Documents2.1 ASTM Standards:2D8 Terminology Relating to Materials for Roads and Pave-mentsD 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 698 Test Methods for Laboratory Compaction Character-istics of Soil Using Standard Effort (12,400 ft-lbf/ft (600kN-m/m)D 24
11、87 Test Method for Classification of Soils for Engi-neering Purposes (Unified Soil Classification System)D 2488 Practice for Description and Identification of Soils(Visual-Manual Procedure)D 3839 Practice for Underground Installation of Fiberglass(Glass-Fiber Reinforced Thermosetting Resin) PipeD 43
12、18 Test Method for Liquid Limit, Plastic Limit, andPlasticity Index of SoilsF 412 Terminology Relating to Plastic Piping Systems3. Terminology3.1 GeneralDefinitions used in this practice are in accor-dance with Terminologies F 412 and D 8 and TerminologyD 653 unless otherwise indicated.3.2 Definitio
13、ns of Terms Specific to This Standard:3.2.1 foundation, bedding, haunching, initial backfill, finalbackfill, pipe zone, excavated trench widthSee Fig. 1 formeaning and limits, and trench terminology.3.2.2 aggregatea granular material of mineral composi-tion such as sand, gravel, shell, slag or crush
14、ed stone (seeTerminology D8).3.2.3 deflectionany change in the inside diameter of thepipe resulting from installation and imposed loads. Deflection1This practice is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.62 on SewerP
15、ipe.Current edition approved August 1, 2005. Published September 2005. Originallyapproved in 1989. Last previous edition approved in 2004 as D 2321 04e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMSt
16、andards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.may be either vertical or horizontal and is usually reported asa percentage of the base (unde
17、flected) inside pipe diameter.3.2.4 dense-graded aggregatean aggregate that has aparticle size distribution such that, when it is compacted, theresulting voids between the aggregate particles, expressed as apercentage of the total space occupied by the material, arerelatively small.3.2.5 engineerthe
18、 engineer in responsible charge of thework or his duly recognized or authorized representative.3.2.6 manufactured aggregatesaggregates such as slagthat are products or byproducts of a manufacturing process, ornatural aggregates that are reduced to their final form by amanufacturing process such as c
19、rushing.3.2.7 open-graded aggregatean aggregate that has a par-ticle size distribution such that, when it is compacted, the voidsbetween the aggregate particles, expressed as a percentage ofthe total space occupied by the material, are relatively large.3.2.8 optimum moisture contentThe moisture cont
20、ent ofsoil at which its maximum density is obtained (see TestMethods D 698).3.2.9 processed aggregatesaggregates that are screened,washed, mixed, or blended to produce a specific particle sizedistribution.3.2.10 standard proctor densitythe maximum dry unitweight of soil compacted at optimum moisture
21、 content, asobtained by laboratory test in accordance with Test MethodsD 698.4. Significance and Use4.1 This practice is for use by designers and specifiers,installation contractors, regulatory agencies, owners, and in-spection organizations who are involved in the construction ofsewers and other gr
22、avity-flow applications that utilize flexiblethermoplastic pipe. As with any standard practice, modifica-tions may be required for specific job conditions or for speciallocal or regional conditions. Recommendations for inclusion ofthis practice in contract documents for a specific project aregiven i
23、n Appendix X2.5. Materials5.1 ClassificationMaterials for use as foundation, embed-ment, and backfill are classified in Table 1. They includenatural, manufactured, and processed aggregates and the soiltypes classified according to Test Method D 2487.NOTE 4See Practice D 2488 for a visual-manual proc
24、edure for fieldidentification of soils.NOTE 5Processed materials produced for highway construction, in-cluding coarse aggregate, base, subbase, and surface course materials,when used for foundation, embedment, and backfill, should be classifiedin accordance with this section and Table 1 according to
25、 particle size,shape and gradation.5.2 Installation and UseTable 2 provides recommenda-tions on installation and use based on class of soil or aggregatesand location in the trench.5.2.1 Use of Class I to Class IVA Soils and AggregatesThese materials may be used as recommended in Table 2,unless other
26、wise specified.5.2.2 Use of Class IV-B and Class V Soils and FrozenMaterialsThese materials are not recommended for embed-ment, and should be excluded from the final backfill exceptwhere allowed by project specifications.5.3 Description of Embedment MaterialSections 5.3.1through 5.3.5 describe chara
27、cteristics of materials recom-mended for embedment.5.3.1 Class IA MaterialsClass IA materials provide maxi-mum stability and pipe support for a given density due toangular interlock of particles. With minimum effort thesematerials can be installed at relatively high densities over awide range of moi
28、sture contents. In addition, the high perme-ability of Class IA materials may aid in the control of water,and these materials are often desirable for embedment in rockcuts where water is frequently encountered. However, whenground water flow is anticipated, consideration should be givento the potent
29、ial for migration of fines from adjacent materialsinto the open-graded Class IA materials (see X1.8).5.3.2 Class IB MaterialsClass IB materials are processedby mixing Class IA and natural or processed sands to producea particle size distribution that minimizes migration fromadjacent materials that c
30、ontain fines (see X1.8). They are moredensely graded than Class IA materials and thus require morecompactive effort to achieve the minimum density specified.When properly compacted, Class IB materials offer highstiffness and strength and, depending on the amount of fines,may be relatively free drain
31、ing.5.3.3 Class II MaterialsClass II materials, when com-pacted, provide a relatively high level of pipe support. In mostrespects, they have all the desirable characteristics of Class IBmaterials when densely graded. However, open graded groupsmay allow migration and the sizes should be checked forc
32、ompatibility with adjacent material (see X1.8). Typically,Class II materials consist of rounded particles and are lessstable than angular materials unless they are confined andcompacted.FIG. 1 Trench Cross Section Showing TerminologyD 2321 052TABLE 1 Classes of Embedment and Backfill MaterialsClass
33、TypeSoil GroupSymbol D2487Description Percentage Passing Sieve Sizes Atterberg Limits Coefficients112 in.(40 mm)No. 4(4.75 mm)No. 200(0.075mm)LL PIUni-formityCUCurva-tureCCIA Manufactured Aggregates:open-graded, clean.None Angular, crushed stone orrock, crushed gravel,broken coral, crushed slag,cind
34、ers or shells; large voidcontent, contain little or nofines.100 % #10 % 4 1 to 3GP Poorly-graded gravels andgravel-sand mixtures; littleor no fines.3SW Well-graded sands and grav-elly sands; little or no fines.50 % of“CoarseFraction”6 1to3SP Poorly-graded sands andgravelly sands; little or nofines.3
35、Coarse-Grained Soils, bor-derline clean to w/finese.g. GW-GC,SP-SM.Sands and gravels which areborderline between cleanand with fines.100 % Varies 5 % to12 %Non Plastic Same as for GW,GP, SW andSPIII Coarse-Grained Soils WithFinesGM Silty gravels, gravel-sand-siltmixtures.100 % “ALineSM Silty sands,
36、sand-siltmixtures.50 % of“CoarseFraction”4 or 7 and “ALineIVAAFine-Grained Soils (inor-ganic)ML Inorganic silts and very finesands, rock flour, silty orclayey fine sands, silts withslight plasticity.100 % 100 % 50 % 7 and “ALineIVB Fine-Grained Soils (inor-ganic)MH Inorganic silts, micaceous ordiato
37、maceous fine sandy orsilty soils, elastic silts.100 % 100 % 50 % 50 “A LineV Organic Soils OL Organic silts and organic siltyclays of low plasticity.100 % 100 % 50 % 50 “A LineHighly Organic PT Peat and other high organicsoils.AIncludes Test Method D 2487 borderline classifications and dual symbols
38、depending on plasticity index and liquid limits.Note“Coarse Fraction as used in this table is defined as material retained on a No. 200 sieve.D 2321 053TABLE 2 Recommendations for Installation and Use of Soils and Aggregates for Foundation, Embedment and BackfillSoil Class (see Table 1)AClass IA Cla
39、ss IB Class II Class III Class IV-AGeneral Recommenda-tions and RestrictionsDo not use where condi-tions may cause mi-gration of fines fromadjacent soil and lossof pipe support. Suit-able for use as adrainage blanket andunderdrain in rockcuts where adjacentmaterial is suitablygraded (see X1.8).Proce
40、ss materials asrequired to obtain gra-dation which will mini-mize migration of ad-jacent materials (seeX1.8). Suitable for useas drainage blanketand underdrain.Where hydraulic gra-dient exists checkgradation to minimizemigration.“Cleangroups suitable foruse as drainageblanket andunderdrain.Do not us
41、e where waterconditions in trenchmay cause instability.Obtain geotechnicalevaluation ofproposed material.May not be suitableunder high earth fills,surface applied wheelloads, and underheavy vibratory com-pactors and tampers.Do not use wherewater conditions intrench may cause in-stability.Foundation
42、Suitable as foundationand for replacingover-excavated andunstable trenchbottom as restrictedabove. Install andcompact in 6-in.maximum layers.Suitable as foundationand for replacingover-excavated andunstable trenchbottom. Install andcompact in 6-in. max-imum layers.Suitable as a foundationand for rep
43、lacingover-excavated andunstable trenchbottom as restrictedabove. Install andcompact in 6-in. max-imum layers.Suitable as foundationand for replacingover-excavated trenchbottom as restrictedabove. Do not use inthicknesses greaterthan 12 in. total. In-stall and compact in6-in. maximum layers.Suitable
44、 only in undis-turbed condition andwhere trench is dry.Remove all loose ma-terial and provide firm,uniform trench bottombefore bedding isplaced.Bedding Suitable as restrictedabove. Install in 6-in.maximum layers.Level final grade byhand. Minimum depth4 in. (6 in. in rockcuts).Install and compact in
45、6-in. maximum layers.Level final grade byhand. Minimum depth4 in. (6 in. in rockcuts).Suitable as restrictedabove. Install andcompact in 6-in. max-imum layers. Levelfinal grade by hand.Minimum depth 4 in.(6 in. in rock cuts).Suitable only in drytrench conditions. In-stall and compact in6-in. maximum
46、 layers.Level final grade byhand. Minimum depth4 in. (6 in. in rockcuts).Suitable only in drytrench conditions andwhen optimum place-ment and compactioncontrol is maintained.Install and compact in6-in. maximum layers.Level final grade byhand. Minimum depth4 in. (6 in. in rockcuts).Haunching Suitable
47、 as restrictedabove. Install in 6-in.maximum layers.Work in around pipeby hand to provideuniform support.Install and compact in6-in. maximum layers.Work in around pipeby hand to provideuniform support.Suitable as restrictedabove. Install andcompact in 6-in. max-imum layers. Work inaround pipe by han
48、dto provide uniformsupport.Suitable as restrictedabove. Install andcompact in 6-in. max-imum layers. Work inaround pipe by handto provide uniformsupport.Suitable only in drytrench conditions andwhen optimum place-ment and compactioncontrol is maintained.Install and compact in6-in. maximum layers.Wor
49、k in around pipeby hand to provideuniform support.Initial Backfill Suitable as restrictedabove. Install to aminimum of 6 in.above pipe crown.Install and compact to aminimum of 6 in.above pipe crown.Suitable as restrictedabove. Install andcompact to a min-imum of 6 in. abovepipe crown.Suitable as restrictedabove. Install andcompact to a min-imum of 6 in. abovepipe crown.Suitable as restrictedabove. Install andcompact to a min-imum of 6 in. abovepipe crown.Embedment CompactionBPlace and work by handto insure all excavatedvoids and haunchareas
