1、Designation: D 2321 08An 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 () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Def
3、ense.1. Scope*1.1 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 UnitsThe values stated in inch-pound units are to beregarded as standard. The values given in parentheses aremathematical conversions to SI units that are provided forinformation only and are not considered standard.1.4 This standard does not purport to address all of th
10、esafety 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 prior to use.2. Referenced Documents2.1 ASTM Standards:2D8 Terminology Relating to
11、Materials for Roads and Pave-mentsD 420 Guide to Site Characterization for Engineering De-sign and Construction PurposesD 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/ft3(600kN-m/
12、m3)D 1556 Test Method for Density and Unit Weight of Soil inPlace by Sand-Cone MethodD 2216 Test Methods for Laboratory Determination of Wa-ter (Moisture) Content of Soil and Rock by MassD 2235 Specification for Solvent Cement for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe and FittingsD 2412
13、 Test Method for Determination of External LoadingCharacteristics of Plastic Pipe by Parallel-Plate LoadingD 2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D 2488 Practice for Description and Identification of Soils(Visual-Manual Procedure)D 256
14、4 Specification for Solvent Cements for Poly(VinylChloride) (PVC) Plastic Piping SystemsD 2657 Practice for Heat Fusion Joining of Polyolefin Pipeand FittingsD 2855 Practice for Making Solvent-Cemented Joints withPoly(Vinyl Chloride) (PVC) Pipe and FittingsD 2922 Test Methods for Density of Soil and
15、 Soil-Aggregate in Place by Nuclear Methods (Shallow Depth)31This practice is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.62 on Sewer.Current edition approved Dec. 1, 2008. Published January 2009. Originallyapproved in 19
16、89. Last previous edition approved in 2005 as D 2321 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3With
17、drawn. The last approved version of this historical standard is referencedon www.astm.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.D 3017 Test Method for Water
18、Content of Soil and Rock inPlace by Nuclear Methods (Shallow Depth)D 3839 Guide for Underground Installation of “Fiberglass”(Glass-FiberReinforced Thermosetting-Resin) PipeD 4318 Test Methods for Liquid Limit, Plastic Limit, andPlasticity Index of SoilsF 402 Practice for Safe Handling of Solvent Cem
19、ents,Primers, and Cleaners Used for Joining Thermoplastic Pipeand FittingsF 412 Terminology Relating to Plastic Piping SystemsF 477 Specification for Elastomeric Seals (Gaskets) forJoining Plastic PipeF 545 Specification for PVC and ABS Injected SolventCemented Plastic Pipe Joints3F 913 Specificatio
20、n for Thermoplastic Elastomeric Seals(Gaskets) for Joining Plastic Pipe2.2 AASHTO Standard:4AASHTO M145 Classification of Soils and Soil AggregateMixtures3. Terminology3.1 GeneralDefinitions used in this practice are in accor-dance with Terminologies F 412 and D 8 and TerminologyD 653 unless otherwi
21、se indicated.3.2 Definitions 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, gr
22、avel, shell, slag or crushed stone (seeTerminology D8).3.2.3 deflectionany change in the inside diameter of thepipe resulting from installation and imposed loads. Deflectionmay be either vertical or horizontal and is usually reported asa percentage of the base (undeflected) inside pipe diameter.3.2.
23、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 engineer in responsible charge of
24、 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 crushing.3.2.7 open-graded aggregat
25、ean 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 content ofsoil at which its maximum de
26、nsity 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 content, asobtained by laboratory
27、 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 gravity-flow applications that utili
28、ze 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 in Appendix X2.5. Materials5.1 Clas
29、sificationSoil types used or encountered in bury-ing pipes include those classified in Table 1 and natural,manufactured, and processed aggregates. The soil classifica-tions are grouped into soil classifications in Table 2 based onthe typical soil stiffness when compacted. Class I indicates asoil tha
30、t generally provides the highest soil stiffness at anygiven percentage of maximum Proctor density, and provides agiven soil stiffness with the least compactive effort. Eachhigher-number soil class provides successively less soil stiff-ness at a given percentage of maximum Proctor density andrequires
31、 greater compactive effort to provide a given level ofsoil stiffnessNOTE 4See Practices D 2487 and D 2488 for laboratory and fieldvisual-manual procedures for identification of soils.NOTE 5Processed materials produced for highway construction, in-cluding coarse aggregate, base, subbase, and surface
32、coarse materials,when used for foundation, embedment, and backfill, should be categorizedin accordance with this section and Table 1 in accordance with particlesize and gradation.5.2 Installation and UseTable 3 provides recommenda-tions on installation and use based on soil classification and4Availa
33、ble from American Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.FIG. 1 Trench Cross Section Showing TerminologyD 2321 082TABLE 1 Soil Classification Chart (see Classification D 2487)Criteria for
34、 Assigning Group Symbols and Group Names Using Laboratory TestsASoil ClassificationGroupSymbolGroup NameBCoarse-Grained Soils gravels clean gravels C $ 4 and 1 # Cc # 3CGW well-graded gravelDMore than 50%retained on No. 200sievemore than 50%of coarse fractionretained on No. 4 sieveless than5% of fin
35、esECu Cc 3CGP poorly graded gravelDgravels with finesmore than12 % finesEFines classify as ML or MH GM silty gravelDFGFines classify as CL or CH GC clayey gravelDFGsands clean sands Cu $ 6 and 1 # Cc # 3CSW well-graded sandH50% or more ofcoarse fractionpasses on No. 4 sieveless than5% finesICu Cc 3C
36、SP poorly graded sandHsand with fines Fines cLassify as ML or MH SM silty sandFGHmore than12 % finesIFines classify as CL or CH SC clayey sandFGHFine-Grained Soils silts and clays inorganic PI 7 and plots on or above “A” lineJCL lean clayKLM50% or more passesthe No. 200 sieveliquid limitless than 50
37、PI 12 % passing #200 sieve; Sandy orgravelly fine-grained soils: CL, ML, orany soil beginning with one of thesesymbols, with 30 % retained on #200sieveClass IIIA-2-4, A-2-5, A-2-6, or A-4or A-6 soils with morethan 30% retained on#200 sieveFine-grained soils:CL, ML, or any soil beginning with oneof t
38、hese symbols, with /=30 %retained on #200 sieveClass IVA-2-7, or A-4, or A-6 soilswith 30% or less retainedon #200 sieveMH, CH, OL, OH, PTClass VNot for useas embedmentA5, A7ASee Classification D 2487, Standard Classification of Soils for Engineering Purposes (Unified Soil Classification System).BAA
39、SHTO M145, Classification of Soils and Soil Aggregate Mixtures.CAll particle faces shall be fractured.DMaterials such as broken coral, shells, and recycled concrete, with # =12% passing a No. 200 sieve, are considered to be Class II materials. These materials shouldonly be used when evaluated and ap
40、proved by the EngineerEUniform fine sands (SP) with more than 50% passing a No. 100 sieve (0.006 in., 0.15 mm) are very sensitive to moisture and should not be used as backfill unlessspecifically allowed in the contract documents. If use of these materials is allowed, compaction and handling procedu
41、res should follow the guidelines for Class III materials.D 2321 084contains rocks, cobbles, etc., the engineer may require greaterinitial backfill cover levels (see Fig. 1).6. Trench Excavation6.1 GeneralProcedures for trench excavation that areespecially important in flexible thermoplastic pipe ins
42、tallationsare given herein.6.1.1 ExcavationExcavate trenches to ensure that sideswill be stable under all working conditions. Slope trench wallsor provide supports in conformance with all local and nationalstandards for safety. Open only as much trench as can be safelymaintained by available equipme
43、nt. Backfill all trenches assoon as practicable, but not later than the end of each workingday.6.2 Water ControlDo not lay or embed pipe in standing orrunning water. At all times prevent runoff and surface waterfrom entering the trench.6.2.1 Ground WaterWhen groundwater is present in thework area, d
44、ewater to maintain stability of in-situ and importedmaterials. Maintain water level below pipe bedding and foun-dation to provide a stable trench bottom. Use, as appropriate,sump pumps, well points, deep wells, geofabrics, perforatedunderdrains, or stone blankets of sufficient thickness to removeand
45、 control water in the trench. When excavating whiledepressing ground water, ensure the ground water is below thebottom of cut at all times to prevent washout from behindsheeting or sloughing of exposed trench walls. Maintaincontrol of water in the trench before, during, and after pipeinstallation, a
46、nd until embedment is installed and sufficientbackfill has been placed to prevent flotation of the pipe. Topreclude loss of soil support, employ dewatering methods thatminimize removal of fines and the creation of voids in in-situmaterials.6.2.2 Running WaterControl running water emanatingfrom drain
47、age of surface or ground water to preclude under-mining of the trench bottom or walls, the foundation, or otherzones of embedment. Provide dams, cutoffs or other barriersTABLE 3 Recommendations for Installation and Use of Soils and Aggregates for Foundation and Pipe-Zone EmbedmentSoil ClassAClass IB
48、Class II Class III Class IVGeneralRecommendationsand RestrictionsAcceptable and commonwhere no migrationis probable or whencombined with a geotextilefilter media.Suitable for use as adrainage blanketand under drainwhere adjacent material issuitably graded or whenused with a geotextile filter fabric(
49、see X1.8).Where hydraulic gradient existscheck gradation to minimizemigration. Clean groups are suitablefor use as a drainage blanket andunderdrain (see Table 2). Uniformfine sands (SP) withmore than 50 % passing a #100 sieve(0.006 in., 0.15 mm)behave like silts and should betreated asClass III soils.Do not use where waterconditions in trench preventproper placement and compaction.Not recommended for usewith pipes with stiffnessof 9 psi or lessDifficult to achieve high-soilstiffness. Do not use where waterconditions in trenchprevent proper placementand co
