1、Designation: D2321 09An American National StandardStandard Practice forUnderground Installation of Thermoplastic Pipe for Sewersand Other Gravity-Flow Applications1This standard is issued under the fixed designation D2321; the number immediately following the designation indicates the year oforigina
2、l 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 Defen
3、se.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 conditions
4、.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 thi
5、s 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, w
6、hen 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 in
7、 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 D420, Test Method D1556, MethodD2216, Specification D2235, Test Method D2412, Specification D2564,Practice D2657, Pract
8、ice D2855, Test Methods D2922, Test MethodD3017, Practice F402, Specification F477, Specification F545, andSpecification F913.NOTE 3Most Plumbing Codes and some Building Codes have provi-sions for the installation of underground “building drains and buildingsewers.” See them for plumbing piping appl
9、ications.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 thesafety concerns
10、, 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 Materials for Ro
11、ads and Pave-mentsD420 Guide to Site Characterization for Engineering De-sign and Construction PurposesD653 Terminology Relating to Soil, Rock, and ContainedFluidsD698 Test Methods for Laboratory Compaction Character-istics of Soil Using Standard Effort (12 400 ft-lbf/ft3(600kN-m/m3)D1556 Test Metho
12、d for Density and Unit Weight of Soil inPlace by Sand-Cone MethodD2216 Test Methods for Laboratory Determination of Wa-ter (Moisture) Content of Soil and Rock by MassD2235 Specification for Solvent Cement for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe and FittingsD2412 Test Method for Determ
13、ination of External LoadingCharacteristics of Plastic Pipe by Parallel-Plate LoadingD2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D2488 Practice for Description and Identification of Soils(Visual-Manual Procedure)D2564 Specification for Solven
14、t Cements for Poly(VinylChloride) (PVC) Plastic Piping SystemsD2657 Practice for Heat Fusion Joining of Polyolefin Pipeand Fittings1This 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
15、approved Dec. 15, 2009. Published February 2010. Originallyapproved in 1989. Last previous edition approved in 2008 as D2321 08. DOI:10.1520/D2321-09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStand
16、ards volume information, refer to the standards Document Summary page onthe ASTM website.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.D2855 Practice for Making Solv
17、ent-Cemented Joints withPoly(Vinyl Chloride) (PVC) Pipe and FittingsD2922 Test Methods for Density of Soil and Soil-Aggregatein Place by Nuclear Methods (Shallow Depth)3D3017 Test Method for Water Content of Soil and Rock inPlace by Nuclear Methods (Shallow Depth)D3839 Guide for Underground Installa
18、tion of “Fiberglass”(Glass-FiberReinforced Thermosetting-Resin) PipeD4318 Test Methods for Liquid Limit, Plastic Limit, andPlasticity Index of SoilsF402 Practice for Safe Handling of Solvent Cements, Prim-ers, and Cleaners Used for Joining Thermoplastic Pipe andFittingsF412 Terminology Relating to P
19、lastic Piping SystemsF477 Specification for Elastomeric Seals (Gaskets) for Join-ing Plastic PipeF545 Specification for PVC and ABS Injected SolventCemented Plastic Pipe Joints3F913 Specification for Thermoplastic Elastomeric Seals(Gaskets) for Joining Plastic PipeF1668 Guide for Construction Proced
20、ures for Buried PlasticPipe2.2 AASHTO Standard:4AASHTO M145 Classification of Soils and Soil AggregateMixtures3. Terminology3.1 GeneralDefinitions used in this practice are in accor-dance with Terminologies F412 and D8 and Terminology D653unless otherwise indicated.3.1.1 Terminology D653 definitions
21、 used in this standard:3.1.2 compaction curve (Proctor curve) (moisture-densitycurve)the curve showing the relationship between the dryunit weight (density) and the water content of a soil for a givencompactive effort.3.1.3 optimum water content the water content at which asoil can be compacted to a
22、 maximum dry unit weight by agiven compactive effort.3.1.4 percent compactionthe ratio, expressed as a percent-age, of: (1) dry unit weight of a soil, to (2) maximum unitweight obtained in a laboratory compaction test.3.1.5 maximum unit weightthe dry unit weight defined bythe peak of a compaction cu
23、rve.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, gravel, she
24、ll, 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.3.2.4 enginee
25、rthe engineer in responsible charge of thework or his duly recognized or authorized representative.3.2.5 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
26、as crushing.3.2.6 modulus of soil reaction (E)an empirical valueused in the Iowa deflection formula that defines the stiffness ofthe soil embedment around a buried pipe3.2.7 open-graded aggregatean aggregate that has a par-ticle size distribution such that, when it is compacted, the voidsbetween the
27、 aggregate particles, expressed as a percentage ofthe total space occupied by the material, are relatively large.3.2.8 processed aggregatesaggregates that are screened,washed, mixed, or blended to produce a specific particle sizedistribution.3.2.9 secant constrained soil modulus (Ms)- a value forsoi
28、l stiffness determined as the secant slope of the stress-straincurve of a one-dimensional compression test; Mscan be usedin place of E in the Iowa deflection formula.3.2.10 standard proctor densitythe maximum dry unitweight of soil compacted at optimum moisture content, asobtained by laboratory test
29、 in accordance with Test MethodsD698.4. 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 utilize fle
30、xiblethermoplastic 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 X2.3Withdrawn. The last appro
31、ved version of this historical standard is referencedon www.astm.org.4Available from American Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.* See 7.6 Minimum CoverFIG. 1 Trench Cross SectionD232
32、1 0925. Materials5.1 ClassificationSoil 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. Cl
33、ass I indicates asoil that generally provides the highest soil stiffness at anygiven percent compaction, and provides a given soil stiffnesswith the least compactive effort. Each higher-number soil classprovides successively less soil stiffness at a given percentcompaction and requires greater compa
34、ctive effort to provide agiven level of soil stiffnessNOTE 4See Practices D2487 and D2488 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 coarse materials
35、,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 andlocation in the trench.
36、 Soil Classes I to IV should be used asrecommended in Table 3. Soil Class V, including clays and siltswith liquid limits greater than 50, organic soils, and frozensoils, shall be excluded from the pipe-zone embedment.5.2.1 Class I Class I materials provide maximum stabilityand pipe support for a giv
37、en percent compaction due to the lowcontent of sand and fines. With minimum effort these materialscan be installed at relatively high-soil stiffnesses over a widerange of moisture contents. In addition, the high permeabilityof Class I materials may aid in the control of water, and thesematerials are
38、 often desirable for embedment in rock cuts wherewater is frequently encountered. However, when ground-waterflow is anticipated, consideration should be given to thepotential for migration of fines from adjacent materials into theopen-graded Class I materials. (See X1.8.)5.2.2 Class IIClass II mater
39、ials, when compacted, pro-vide a relatively high level of pipe support; however, open-graded groups may allow migration and the sizes should bechecked for compatibility with adjacent material. (See X1.8.)5.2.3 Class III Class III materials provide less support fora given percent compaction than Clas
40、s I or Class II materials.Higher levels of compactive effort are required and moisturecontent must be near optimum to minimize compactive effortand achieve the required percent compaction. These materialsprovide reasonable levels of pipe support once proper percentcompaction is achieved.5.2.4 Class
41、IVClass IV materials require a geotechnicalevaluation prior to use. Moisture content must be near opti-mum to minimize compactive effort and achieve the requiredpercent compaction. Properly placed and compacted, Class IVmaterials can provide reasonable levels of pipe support;however, these materials
42、 may not be suitable under high fills,surface-applied wheel loads, or under high-energy-level vibra-tory compactors and tampers. Do not use where water condi-tions in the trench may prevent proper placement and compac-tion.NOTE 6The term “high energy level vibratory compactors andtampers” refers to
43、compaction equipment that might deflect or distort thepipe more than permitted by the specifications or the manufacturer.5.2.5 Class VClass V materials should be excluded frompipe-zone embedment.5.3 Moisture Content of Embedment MaterialsThe mois-ture content of embedment materials must be controlle
44、d topermit placement and compaction to required levels. For soilswith low permeability (that is, Class III and Class IV and someborderline Class II soils), moisture content is normally con-trolled to 6 3 % of optimum (see Test Method D698). Thepracticality of obtaining and maintaining the required l
45、imits onmoisture content is an important criterion for selecting mate-rials, since failure to achieve required percent compaction,especially in the pipe zone embedment, may result in excessivedeflection.5.4 Maximum Particle SizeMaximum particle size forembedment is limited to material passing a 112-
46、in. (37.5-mm)sieve (see Table 2). To enhance placement around smalldiameter pipe and to prevent damage to the pipe wall, a smallermaximum size may be required (see X1.9). When final backfillcontains rocks, cobbles, etc., the engineer may require greaterinitial backfill cover levels (see Fig. 1).6. T
47、rench Excavation6.1 GeneralProcedures for trench excavation that areespecially important in flexible thermoplastic pipe installationsare given herein.6.1.1 ExcavationExcavate trenches to ensure that sideswill be stable under all working conditions. Slope trench wallsor provide supports in conformanc
48、e with all local and nationalstandards for safety. Open only as much trench as can be safelymaintained by available equipment. 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 time
49、s prevent runoff and surface waterfrom entering the trench.6.2.1 Ground WaterWhen groundwater is present in thework area, dewater 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 control water in the trench. When excavating whiledepressing ground water, ensure the ground water is below thebottom of cut
