1、Designation: F1759 97 (Reapproved 2010) An American National StandardStandard Practice forDesign of High-Density Polyethylene (HDPE) Manholes forSubsurface Applications1This standard is issued under the fixed designation F1759; the number immediately following the designation indicates the year ofor
2、iginal 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.1. Scope1.1 This practice covers general and basic procedures re-lated to
3、 the design of manholes and components manufacturedfrom high-density polyethylene (HDPE) for use in subsurfaceapplications and applies to personnel access structures. Thepractice covers the material, the structural design requirementsof the manhole barrel (also called vertical riser or shaft), floor
4、(bottom), and top, and joints between shaft sections.1.2 This practice offers the minimum requirements for theproper design of an HDPE manhole. Due to the variability inmanhole height, diameter, and the soil, each manhole must bedesigned and detailed individually. When properly used andimplemented,
5、this practice can help ensure a safe and reliablestructure for the industry.1.3 DisclaimerThe reader is cautioned that independentprofessional judgment must be exercised when data or recom-mendations set forth in this practice are applied. The publica-tion of the material contained herein is not int
6、ended as arepresentation or warranty on the part of ASTM that thisinformation is suitable for general or particular use, or freedomfrom infringement of any patent or patents.Anyone making useof this information assumes all liability arising from such use.The design of structures is within the scope
7、of expertise of alicensed architect, structural engineer, or other licensed profes-sional for the application of principles to a particular structure.1.4 The values stated in inch-pound units are to be regardedas the standard. The SI units given in parentheses are providedfor information only.1.5 Th
8、is 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 prior to use.2. Referenced Documen
9、ts2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and ContainedFluidsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsD2321 Practice for Underground Installation of Thermoplas-tic Pipe for Sewers and Other Gravity-Flow ApplicationsD2657 Practice for Heat Fusion Joining of Pol
10、yolefin Pipeand FittingsD2837 Test Method for Obtaining Hydrostatic Design Basisfor Thermoplastic Pipe Materials or Pressure Design Basisfor Thermoplastic Pipe ProductsD3035 Specification for Polyethylene (PE) Plastic Pipe (DR-PR) Based on Controlled Outside DiameterD3212 Specification for Joints fo
11、r Drain and Sewer PlasticPipes Using Flexible Elastomeric SealsD3350 Specification for Polyethylene Plastics Pipe and Fit-tings MaterialsF412 Terminology Relating to Plastic Piping SystemsF477 Specification for Elastomeric Seals (Gaskets) for Join-ing Plastic PipeF714 Specification for Polyethylene
12、(PE) Plastic Pipe (DR-PR) Based on Outside DiameterF894 Specification for Polyethylene (PE) Large DiameterProfile Wall Sewer and Drain Pipe3. Terminology3.1 Definitions:3.1.1 Definitions used in this practice are in accordance withTerminology F412 and Terminology D1600 unless otherwiseindicated.3.2
13、Definitions of Terms Specific to This Standard:3.2.1 anchor connection ringan HDPE ring attached tothe manhole riser on which to place an antiflotation device,such as a concrete anchor ring.1This practice is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct resp
14、onsibility of Subcommittee F17.26 on OlefinBased Pipe.Current edition approved April 1, 2010. Published May 2010. Originallyapproved in 1997. Last previous edition approved in 2004 as F1759 - 97 (2004).DOI: 10.1520/F1759-97R10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orc
15、ontact 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 Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international st
16、andard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2
17、.2 archingmobilization of internal shear resistancewithin a soil mass that results in a change in soil pressureacting on an underground structure.3.2.3 benchingthe internal floor of a manhole when it iselevated above the manhole invert, usually provided as a placefor personnel to stand.3.2.4 closed
18、profilea manhole barrel construction thatpresents an essentially smooth internal surface braced withprojections or ribs, which are joined by an essentially smoothouter wall. Solid wall construction is considered a special caseof the closed profile.3.2.5 downdragdownward shear force acting on theshaf
19、ts external surface and resulting from settlement of themanhole backfill.3.2.6 extrusion weldinga joining technique that is accom-plished by extruding a molten polyethylene bead between twoprepared surface ends.3.2.7 floorthe lowest internal surface of the manhole. Thefloor and bottom are often the
20、same.3.2.8 inlet/outletpipe (conduit) passing through the wallof the manhole.3.2.9 invertthe flow channel in the floor of a manhole.This may consist of the lower half of a pipe, thus the name“invert”.3.2.10 manholean underground service access structure,which can access pipelines, conduits, or subsu
21、rface equipment.3.2.11 manhole bottomthe lowest external surface of themanhole.3.2.12 manhole conethe top portion of the manholethrough which entrance to the manhole is made and where thediameter may increase from the entrance way to the largermanhole barrel. Sometimes referred to as the manway redu
22、cer.3.2.13 open profilea manhole barrel construction thatpresents an essentially smooth internal surface with a ribbed orcorrugated external surface. Open profile barrel constructionsare normally not used for manholes.3.2.14 performance limitsmechanisms by which the func-tion of a structure may beco
23、me impaired.3.2.15 riserthe vertical barrel or “shaft” section of amanhole.3.3 See Fig. 1 for illustration of manhole terminology.4. Significance and Use4.1 UsesThe requirements of this practice are intended toprovide manholes suitable for installation in pipeline or conduittrenches, landfill perime
24、ters, and landfills with limited settle-ment characteristics. Direct installation in sanitary landfills orother fills subject to large (in excess of 10 %) soil settlementsmay require special designs outside the scope of this practice.4.1.1 Manholes are assumed to be subject to gravity flowonly.4.2 D
25、esign AssumptionThe design methodology in thispractice applies only to manholes that are installed in backfillconsisting of Class I, Class II, or Class III material as definedin Practice D2321, which has been compacted to a minimum of90 % standard proctor density. The designs are based on thebackfil
26、l extending at least 3.5 ft (1 m) from the perimeter of themanhole for the full height of the manhole and extendinglaterally to undisturbed in situ soil. Manholes are assumedplaced on a stable base consisting of at least 12 in. (30.5 cm)of Class I material compacted to at least 95 % standard proctor
27、density or a concrete slab. The foundation soils under the basemust provide adequate bearing strength to carry downdragloads.4.2.1 Manholes installed in sanitary landfills or other fillsexperiencing large settlements may require special designsbeyond the scope of this practice. The designer should e
28、valuateeach specific site to determine the suitability for use of HDPEmanholes and the designer should prepare a written specifica-tion for installation, which is beyond the scope of this practice.5. Materials5.1 HDPE MaterialManhole components, such as theriser, base, and anchor connection ring, sh
29、all be made of HDPEplastic compound having a cell classification of 334433C orhigher, in accordance with Specification D3350.NOTE 1Materials for use in manholes may be subjected to significanttensile and compressive stresses. The material must have a provencapacity for sustaining long-term stresses.
30、 There are no existing ASTMstandards that establish such a stress rating except for Test Method D2837.Work is currently in progress to develop an alternate method for stressrating materials and when completed, this standard will be alteredaccordingly.5.2 Other MaterialManhole components, such as top
31、s andlids, may be fabricated from materials other than HDPE as longas agreed to by the user and manufacturer.FIG. 1 Manhole TerminologyF1759 97 (2010)26. Subsurface Loading on Manhole Riser6.1 Performance LimitsThe manhole risers performancelimits include ring deflection, ring (hoop) and axial stres
32、s (orstrain), and ring and axial buckling. Radially directed loadsacting on a manhole cause ring deformation and ring bendingstresses. The radial load varies along the length of the manhole.See Fig. 2. In addition to radial stresses, considerable axialstress may exist in the manhole wall as a result
33、 of “downdrag”.Downdrag occurs as the backfill soil surrounding the manholeconsolidates and settles. Axial load is induced through thefrictional resistance of the manhole to the backfill settlement.See Fig. 3. The manhole must also be checked for axialcompressive stress and axial buckling due to dow
34、ndrag forces.6.2 Earth Pressure Acting on Manhole Riser:6.2.1 Radial PressureRadial pressure along the length ofthe manhole riser may be calculated using finite elementmethods, field measurements, or other suitable means. SeeHossain and Lytton (1).3In lieu of the preceding, the activeearth pressure
35、modified for uneven soil compaction around theperimeter of the riser can be used.NOTE 2Use of the active pressure is based on measurements taken byGartung et al. (2) and on the ability of the material placed around themanhole to accept tangential stresses and thus relieve some of the lateralpressure
36、. It may actually understate the load on the manhole, however thisappears to be offset by the stress relaxation that occurs in the HDPEmanhole as shown by Hossain (3). Stress relaxation permits mobilizationof horizontal arching, thus the active earth pressure can be assumed fordesign purposes.6.2.1.
37、1 If the active earth pressure is modified to take intoaccount uneven compaction around the perimeter of the pipe asdescribed by Steinfeld and Partner (4), the radially directeddesign pressure is given by Eq 1.PR5 1.21 KAH (1)where:PR= applied radial pressure, psf (KPa), = soil unit weight, lbs/ft3(
38、kN/m3),H = weight of fill, ft (m), andKA= active earth pressure coefficient as given by Eq 2.KA5 tan2S45 22D(2)where: = angle of internal friction of manhole embedmentmaterial, .6.2.2 Downdrag (Axial Shear Stress)The settlement ofbackfill material surrounding a manhole riser develops a shearstress b
39、etween the manhole and the fill, which acts as “down-drag” along the outside of the manhole. The settling processbegins with the first lift of fill placed around the manhole andcontinues until all the fill is placed and consolidated. As fill isplaced around a manhole, the axial force coupled into th
40、emanhole by downdrag shear will increase until it equals thefrictional force between the soil and manhole. When this limitis reached, slippage of the fill immediately adjacent to themanhole occurs. This limits the axial force to the value of thefrictional force.6.2.2.1 Downdrag loads can be calculat
41、ed using finite ele-ment methods, field measurements, or other procedures. In lieuof these, the following method may be used. The average shearstress is given by Eq 3, for an active earth pressure distributionas shown in Fig. 2.TA5 FPR11PR22G(3)where:TA= average shear (frictional) stress, psf (kPa),
42、PR1= radial earth pressure at top of manhole, psf (kPa),PR2= radial earth pressure at bottom of manhole, psf (kPa),and = coefficient of friction between manhole and soil.6.2.2.2 The coefficient of friction between an HDPE man-hole with an essentially smooth outer surface and a granular orgranular-co
43、hesive soil can be taken as 0.4. See Swan et al. (5)and Martin et al. (6). In some applications the coefficient offriction may be reduced by coating the exterior of the manholewith bentonite or some other lubricant.NOTE 3The use of external stiffeners or open profiles to stiffen theriser greatly inc
44、reases the downdrag load due to their impeding the3The boldface numbers given in parentheses refer to a list of references at theend of the text.FIG. 2 Radial Pressure Acting on Manhole (Assumed Distribu-tion for Design)FIG. 3 Downdrag Force Acting on Manhole (Assumed for De-sign)F1759 97 (2010)3set
45、tlement of soil beside the manhole. This has the effect of increasing theaverage shear stress in Eq 3. Where open profiles are used, the coefficientof friction may equal or exceed 1.0.6.2.2.3 The downdrag creates an axial-directed load (down-drag load) in the manhole wall that increases with depth.
46、Theaxial force developed on the manhole can be found byintegrating the shear stress (or frictional stress) between themanhole and soil over the height of the fill. This integration isequal to the product of the surface area of the manhole timesthe average shear stress acting on the surface. The maxi
47、mumdowndrag force can be found using Eq 4. Whether or not toinclude surface vehicular loads in this term depends on themanhole top design. See 7.3.PD5 TASDo12DH (4)where:PD= downdrag load, lb (kN),Do= outside diameter of manhole, in. (m),TA= average shear stress, psf (kPa), andH = height of fill, ft
48、 (m).NOTE 4When SI units are used, the 12 in the denominator of Eq 4may be dropped.NOTE 5This equation can be used for HDPE manholes with therecognition that the HDPE manhole is not unyielding. Axial deflection ofthe HDPE manhole will lessen the downdrag load. The actual load willdepend on the relat
49、ive stiffness between the manhole and the soil and onthe effect of stress relaxation properties on the relative stiffness.6.3 Groundwater Effects:6.3.1 The presence of groundwater around a manhole exertsan external hydrostatic pressure on the riser as well as abuoyant uplift force on the bottom of the manhole. When soilis submerged beneath the groundwater level, the radial earthpressure acting around the outside diameter of the riser isreduced because the buoyant force of the water reduces theeffective weight of the soil. In order to calculate t
