1、Designation: F 1759 97 (Reapproved 2004)An American National StandardStandard Practice forDesign of High-Density Polyethylene (HDPE) Manholes forSubsurface Applications1This standard is issued under the fixed designation F 1759; the number immediately following the designation indicates the year ofo
2、riginal 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.1. Scope1.1 This practice covers general and basic procedures re-lated
3、to 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), flo
4、or(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 i
6、ntended 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 sco
7、pe 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
8、 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 prior to use.2. Referenced Docu
9、ments2.1 ASTM Standards:2D 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 1600 Terminology for Abbreviated Terms Relating toPlasticsD 2321 Practice for Underground Installation of Thermo-plastic Pipe for Sewers and Other Gravity-Flow Applica-tionsD 2657 Practice for Heat Fusion Joining
10、 of Polyolefin Pipeand FittingsD 2837 Test Method for Obtaining Hydrostatic DesignBasis for Thermoplastic Pipe Materials or Pressure DesignBasis for Thermoplastic Pipe ProductsD 3035 Specification for Polyethylene (PE) Plastic Pipe(DR-PR) Based on Controlled Outside DiameterD 3212 Specification for
11、Joints for Drain and Sewer PlasticPipes Using Flexible Elastomeric SealsD 3350 Specification for Polyethylene Plastics Pipe andFittings MaterialsF 412 Terminology Relating to Plastic Piping SystemsF 477 Specification for Elastomeric Seals (Gaskets) forJoining Plastic PipeF 714 Specification for Poly
12、ethylene (PE) Plastic Pipe(SDR-PR) Based on Outside DiameterF 894 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 F 412 and Terminology D 1600 unless otherwisein
13、dicated.3.2 Definitions of Terms Specific to This Standard:1This practice is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.26 on OlefinBased Pipe.Current edition approved Sept. 1, 2004. Published September 2004. Originallya
14、pproved in 1997. Last previous edition approved in 1997 as F 1759 - 97.2For 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 AST
15、M website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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.3.2.2 archingmobilization of int
16、ernal 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 profilea manhole barrel const
17、ruction 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 theshafts external surface and resul
18、ting 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 same.3.2.8 inlet/outletpipe (
19、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 subsurface equipment.3.2.11 manhol
20、e 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 reducer.3.2.13 open profilea manh
21、ole 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 become impaired.3.2.15 riserthe v
22、ertical 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 perimeters, and landfills with limi
23、ted 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 Design AssumptionThe design me
24、thodology in thispractice applies only to manholes that are installed in backfillconsisting of Class I, Class II, or Class III material as definedin Practice D 2321, which has been compacted to a minimumof 90 % standard proctor density. The designs are based on thebackfill extending at least 3.5 ft
25、(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 proctordensity or a concrete slab.
26、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 evaluateeach specific site to
27、 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, shall be made of HDPEplastic c
28、ompound having a cell classification of 334433C orhigher, in accordance with Specification D 3350.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. There are no existing ASTM
29、standards that establish such a stress rating except for Test MethodD 2837. Work is currently in progress to develop an alternate method forstress rating materials and when completed, this standard will be alteredaccordingly.5.2 Other MaterialManhole components, such as topsand lids, may be fabricat
30、ed from materials other than HDPE aslong as agreed to by the user and manufacturer.FIG. 1 Manhole TerminologyF 1759 97 (2004)26. Subsurface Loading on Manhole Riser6.1 Performance LimitsThe manhole risers performancelimits include ring deflection, ring (hoop) and axial stress (orstrain), and ring an
31、d 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 of “downdrag”.Downdrag o
32、ccurs 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 downdrag forces.6.2 Earth Pr
33、essure 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 modified for uneven soil
34、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. It may actually underst
35、ate 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.6.2.1.1 If the active earth pre
36、ssure 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 KAgH (1)where:PR= applied radial pressure, psf (KPa),g = soil unit weight, lbs/ft3(kN/m3),H = weight of fi
37、ll, ft (m), andKA= active earth pressure coefficient as given by Eq 2.KA5 tan2S45 2f2D(2)where:f = 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 between the manhole an
38、d 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 themanhole by downdrag
39、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 calculated using finite ele-m
40、ent 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 FPR11 PR22G(3)where:TA= average shear (frictional) stress, psf (kPa),PR1= radial earth pr
41、essure 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-cohesive soil can be t
42、aken 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 increases the downdrag
43、load due to their impeding thesettlement of soil beside the manhole. This has the effect of increasing 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 Distributionfor Design)FIG. 3 Downdrag Force Acti
44、ng on Manhole (Assumed for Design)F 1759 97 (2004)3average 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. Theaxial force develop
45、ed 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 maximumdowndrag force can
46、be found using Eq 4. Whether or not toinclude surface vehicular loads in this term depends on themanhole top design. See 7.3.PD5 TApSDo12DH (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 (m).NOTE 4When SI un
47、its 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 relative stiffness between
48、 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 soil
49、is 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 the radialpressure acting on the manhole, the groundwater pressure isadded to the radial soil pressure produced by the buoyantweight of the soil. The resulting radial pressure is used whencalculating ring performance limits. For axial performancelimits that are controlled by downdrag forces, the radialpressure should be calcul
