1、Designation:F44902(Reapproved 2014)Standard Practice forSubsurface Installation of Corrugated Polyethylene Pipe forAgricultural Drainage or Water Table Control1This standard is issued under the fixed designation F449;the number immediately following the designation indicates the year of originaladop
2、tion or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice is recommended for and limited to gravityflow subsurface drainage s
3、ystems or water table control,butnot recommended for sanitary or storm sewer applications.Procedures are outlined to minimize pipe deflection or struc-tural damage during and after the installation process.Theseinstallation procedures are in accordance with“flexible con-duit”principles.1.2 This prac
4、tice applies to all agricultural subsurface drain-age or water table control installations using SpecificationF405,F667 or other plastic pipe.1.3 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provi
5、ded for information onlyand are not considered standard.1.4 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 o
6、f regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1600 Terminology forAbbreviated Terms Relating to Plas-ticsD2412 Test Method for Determination of External LoadingCharacteristics of Plastic Pipe by Parallel-Plate LoadingF405 Specification for Corrugated Polyethylene(P
7、E)Pipeand FittingsF412 Terminology Relating to Plastic Piping SystemsF667 Specification for 3 through 24 in.Corrugated Polyeth-ylene Pipe and Fittings3.Terminology3.1 Definitions are in accordance with Terminology F412and abbreviations are in accordance with Terminology D1600,unless otherwise specif
8、ied.3.2 backfillmaterials used to fill the trench followinginstallation of the pipe and bedding.3.3 beddingmaterial which provides stable bottom sup-port for the pipe including the trench bottom groove supportangle or select material placed around the pipe,and envelopeor filter materials where used
9、during installation.3.4 blindingthe placement of soil,bedding material overand on the sides of the pipe or envelope to ensure proper grade,alignment,support,and protection of pipe during backfillingand after installation.3.5 boot(also shield)the protecting apparatus linked tothe rear of the installa
10、tion machine in a manner which allowsplacement of the pipe on the trench bottom,protection of theworkman,or placement of envelope or filter material,or both.3.6 cradlea prefabricated rigid structure designed to pro-vide trench bottom support for the pipe when soil support isinadequate.3.7 envelopepo
11、rous material placed around the pipe toprovide bedding,improve the flow of ground water into thedrain,or function as a filter.3.8 filteran envelope of natural or synthetic materialsplaced completely around a drain to permit free water move-ment into the drain,provide stabilizing support at the soil-
12、filterinterface,and restrict movement of silt and sand into the drain.3.9 gradethe slope of the pipe invert.3.10 groove support angleangle between the radii of thepipe at points of contact with the formed groove of undisturbedsoil or a cradle.3.11 mineral soilssoil containing(1)less than 30%or-ganic
13、 matter by weight provided the mineral fraction is 60%ormore clay,or(2)less than 20%organic matter by weightprovided the mineral fraction has no clay,or(3)less than aproportional content of organic matter between 20 and 30%ifthe clay content of the mineral fraction is between 0 and 60%.1This practic
14、e is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.65 on LandDrainage.Current edition approved March 1,2014.Published September 2014.Originallyapproved in 1976.Last previous edition approved in 2008 as F449 02(2008).DOI:10.
15、1520/F0449-02R14.2For 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.Copyright ASTM International,100 Barr Harbor Driv
16、e,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.12 natural granular envelopean envelope of granularmaterial,usually highly permeable well-graded sand andgravel.3.13 organic soilsoil containing(1)30%or more organicmatter provided the mineral fraction is 60%or more clay,or(2)20%or more organic matter provided the mineral fractionhas no clay,or(3)a proportional content of organic matterbetween 20 and 30%if the clay content of mineral fraction isbetween 0 and 60%.(It is a general rule
