ASTM F1759-97(2010)
(Practice)Standard Practice for Design of High-Density Polyethylene (HDPE) Manholes for Subsurface Applications
Standard Practice for Design of High-Density Polyethylene (HDPE) Manholes for Subsurface Applications
SIGNIFICANCE AND USE
Uses—The requirements of this practice are intended to provide manholes suitable for installation in pipeline or conduit trenches, landfill perimeters, and landfills with limited settlement characteristics. Direct installation in sanitary landfills or other fills subject to large (in excess of 10 %) soil settlements may require special designs outside the scope of this practice.
Manholes are assumed to be subject to gravity flow only.
Design Assumption—The design methodology in this practice applies only to manholes that are installed in backfill consisting of Class I, Class II, or Class III material as defined in Practice D2321, which has been compacted to a minimum of 90 % standard proctor density. The designs are based on the backfill extending at least 3.5 ft (1 m) from the perimeter of the manhole for the full height of the manhole and extending laterally to undisturbed in situ soil. Manholes are assumed placed on a stable base consisting of at least 12 in. (30.5 cm) of Class I material compacted to at least 95 % standard proctor density or a concrete slab. The foundation soils under the base must provide adequate bearing strength to carry downdrag loads.
Manholes installed in sanitary landfills or other fills experiencing large settlements may require special designs beyond the scope of this practice. The designer should evaluate each specific site to determine the suitability for use of HDPE manholes and the designer should prepare a written specification for installation, which is beyond the scope of this practice.
SCOPE
1.1 This practice covers general and basic procedures related to the design of manholes and components manufactured from high-density polyethylene (HDPE) for use in subsurface applications and applies to personnel access structures. The practice covers the material, the structural design requirements of the manhole barrel (also called vertical riser or shaft), floor (bottom), and top, and joints between shaft sections.
1.2 This practice offers the minimum requirements for the proper design of an HDPE manhole. Due to the variability in manhole height, diameter, and the soil, each manhole must be designed and detailed individually. When properly used and implemented, this practice can help ensure a safe and reliable structure for the industry.
1.3 Disclaimer—The reader is cautioned that independent professional judgment must be exercised when data or recommendations set forth in this practice are applied. The publication of the material contained herein is not intended as a representation or warranty on the part of ASTM that this information is suitable for general or particular use, or freedom from infringement of any patent or patents. Anyone making use of this information assumes all liability arising from such use. The design of structures is within the scope of expertise of a licensed architect, structural engineer, or other licensed professional for the application of principles to a particular structure.
1.4 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are provided for information only.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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Designation: F1759 − 97 (Reapproved 2010) An American National Standard
Standard Practice for
Design of High-Density Polyethylene (HDPE) Manholes for
Subsurface Applications
This standard is issued under the fixed designation F1759; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This practice covers general and basic procedures re- 2.1 ASTM Standards:
lated to the design of manholes and components manufactured D653 Terminology Relating to Soil, Rock, and Contained
from high-density polyethylene (HDPE) for use in subsurface Fluids
applications and applies to personnel access structures. The D1600 Terminology forAbbreviatedTerms Relating to Plas-
practice covers the material, the structural design requirements tics
of the manhole barrel (also called vertical riser or shaft), floor D2321 PracticeforUndergroundInstallationofThermoplas-
(bottom), and top, and joints between shaft sections. tic Pipe for Sewers and Other Gravity-Flow Applications
D2657 Practice for Heat Fusion Joining of Polyolefin Pipe
1.2 This practice offers the minimum requirements for the
and Fittings
proper design of an HDPE manhole. Due to the variability in
D2837 Test Method for Obtaining Hydrostatic Design Basis
manhole height, diameter, and the soil, each manhole must be
forThermoplasticPipeMaterialsorPressureDesignBasis
designed and detailed individually. When properly used and
for Thermoplastic Pipe Products
implemented, this practice can help ensure a safe and reliable
D3035 SpecificationforPolyethylene(PE)PlasticPipe(DR-
structure for the industry.
PR) Based on Controlled Outside Diameter
D3212 Specification for Joints for Drain and Sewer Plastic
1.3 Disclaimer—The reader is cautioned that independent
Pipes Using Flexible Elastomeric Seals
professional judgment must be exercised when data or recom-
D3350 Specification for Polyethylene Plastics Pipe and Fit-
mendations set forth in this practice are applied. The publica-
tings Materials
tion of the material contained herein is not intended as a
F412 Terminology Relating to Plastic Piping Systems
representation or warranty on the part of ASTM that this
F477 Specification for Elastomeric Seals (Gaskets) for Join-
information is suitable for general or particular use, or freedom
ing Plastic Pipe
frominfringementofanypatentorpatents.Anyonemakinguse
F714 Specification for Polyethylene (PE) Plastic Pipe (DR-
of this information assumes all liability arising from such use.
PR) Based on Outside Diameter
The design of structures is within the scope of expertise of a
F894 Specification for Polyethylene (PE) Large Diameter
licensed architect, structural engineer, or other licensed profes-
Profile Wall Sewer and Drain Pipe
sional for the application of principles to a particular structure.
1.4 The values stated in inch-pound units are to be regarded
3. Terminology
as the standard. The SI units given in parentheses are provided
3.1 Definitions:
for information only.
3.1.1 Definitionsusedinthispracticeareinaccordancewith
1.5 This standard does not purport to address all of the
Terminology F412 and Terminology D1600 unless otherwise
safety concerns, if any, associated with its use. It is the
indicated.
responsibility of the user of this standard to establish appro-
3.2 Definitions of Terms Specific to This Standard:
priate safety and health practices and determine the applica-
3.2.1 anchor connection ring—an HDPE ring attached to
bility of regulatory limitations prior to use.
the manhole riser on which to place an antiflotation device,
such as a concrete anchor ring.
This practice is under the jurisdiction of ASTM Committee F17 on Plastic
Piping Systems and is the direct responsibility of Subcommittee F17.26 on Olefin
Based Pipe. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2010. Published May 2010. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1997. Last previous edition approved in 2004 as F1759 - 97 (2004). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/F1759-97R10. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1759 − 97 (2010)
3.2.2 arching—mobilization of internal shear resistance
within a soil mass that results in a change in soil pressure
acting on an underground structure.
3.2.3 benching—the internal floor of a manhole when it is
elevated above the manhole invert, usually provided as a place
for personnel to stand.
3.2.4 closed profile—a manhole barrel construction that
presents an essentially smooth internal surface braced with
projections or ribs, which are joined by an essentially smooth
outer wall. Solid wall construction is considered a special case
of the closed profile.
3.2.5 downdrag—downward shear force acting on the
shaft’s external surface and resulting from settlement of the
manhole backfill.
3.2.6 extrusion welding—a joining technique that is accom-
plished by extruding a molten polyethylene bead between two
prepared surface ends.
3.2.7 floor—the lowest internal surface of the manhole. The
floor and bottom are often the same.
3.2.8 inlet/outlet—pipe (conduit) passing through the wall
of the manhole.
3.2.9 invert—the flow channel in the floor of a manhole.
This may consist of the lower half of a pipe, thus the name
“invert”.
FIG. 1 Manhole Terminology
3.2.10 manhole—an underground service access structure,
which can access pipelines, conduits, or subsurface equipment.
inPracticeD2321,whichhasbeencompactedtoaminimumof
90 % standard proctor density. The designs are based on the
3.2.11 manhole bottom—the lowest external surface of the
backfillextendingatleast3.5ft(1m)fromtheperimeterofthe
manhole.
manhole for the full height of the manhole and extending
3.2.12 manhole cone—the top portion of the manhole
laterally to undisturbed in situ soil. Manholes are assumed
through which entrance to the manhole is made and where the
placed on a stable base consisting of at least 12 in. (30.5 cm)
diameter may increase from the entrance way to the larger
of Class I material compacted to at least 95 % standard proctor
manhole barrel. Sometimes referred to as the manway reducer.
density or a concrete slab. The foundation soils under the base
3.2.13 open profile—a manhole barrel construction that
must provide adequate bearing strength to carry downdrag
presents an essentially smooth internal surface with a ribbed or
loads.
corrugated external surface. Open profile barrel constructions
4.2.1 Manholes installed in sanitary landfills or other fills
are normally not used for manholes.
experiencing large settlements may require special designs
3.2.14 performance limits—mechanisms by which the func- beyondthescopeofthispractice.Thedesignershouldevaluate
each specific site to determine the suitability for use of HDPE
tion of a structure may become impaired.
manholes and the designer should prepare a written specifica-
3.2.15 riser—the vertical barrel or “shaft” section of a
tion for installation, which is beyond the scope of this practice.
manhole.
5. Materials
3.3 See Fig. 1 for illustration of manhole terminology.
5.1 HDPE Material—Manhole components, such as the
4. Significance and Use
riser,base,andanchorconnectionring,shallbemadeofHDPE
plastic compound having a cell classification of 334433C or
4.1 Uses—The requirements of this practice are intended to
higher, in accordance with Specification D3350.
providemanholessuitableforinstallationinpipelineorconduit
trenches, landfill perimeters, and landfills with limited settle-
NOTE 1—Materials for use in manholes may be subjected to significant
ment characteristics. Direct installation in sanitary landfills or tensile and compressive stresses. The material must have a proven
capacity for sustaining long-term stresses. There are no existing ASTM
other fills subject to large (in excess of 10 %) soil settlements
standardsthatestablishsuchastressratingexceptforTestMethodD2837.
may require special designs outside the scope of this practice.
Work is currently in progress to develop an alternate method for stress
4.1.1 Manholes are assumed to be subject to gravity flow
rating materials and when completed, this standard will be altered
only.
accordingly.
4.2 Design Assumption—The design methodology in this 5.2 Other Material—Manholecomponents,suchastopsand
practice applies only to manholes that are installed in backfill lids,maybefabricatedfrommaterialsotherthanHDPEaslong
consisting of Class I, Class II, or Class III material as defined as agreed to by the user and manufacturer.
F1759 − 97 (2010)
NOTE 2—Use of the active pressure is based on measurements taken by
Gartung et al. (2) and on the ability of the material placed around the
manhole to accept tangential stresses and thus relieve some of the lateral
pressure. It may actually understate the load on the manhole, however this
appears to be offset by the stress relaxation that occurs in the HDPE
manhole as shown by Hossain (3). Stress relaxation permits mobilization
of horizontal arching, thus the active earth pressure can be assumed for
design purposes.
6.2.1.1 If the active earth pressure is modified to take into
accountunevencompactionaroundtheperimeterofthepipeas
described by Steinfeld and Partner (4), the radially directed
design pressure is given by Eq 1.
P 5 1.21 K γH (1)
R A
where:
P = applied radial pressure, psf (KPa),
R
3 3
FIG. 2 Radial Pressure Acting on Manhole (Assumed Distribu-
γ = soil unit weight, lbs/ft (kN/m ),
tion for Design)
H = weight of fill, ft (m), and
K = active earth pressure coefficient as given by Eq 2.
A
φ
K 5 tan 45 2 (2)
S D
A
where:
φ = angle of internal friction of manhole embedment
material, °.
6.2.2 Downdrag (Axial Shear Stress)—The settlement of
backfill material surrounding a manhole riser develops a shear
stress between the manhole and the fill, which acts as “down-
drag” along the outside of the manhole. The settling process
begins with the first lift of fill placed around the manhole and
continues until all the fill is placed and consolidated. As fill is
placed around a manhole, the axial force coupled into the
manhole by downdrag shear will increase until it equals the
FIG. 3 Downdrag Force Acting on Manhole (Assumed for De-
sign) frictional force between the soil and manhole. When this limit
is reached, slippage of the fill immediately adjacent to the
manhole occurs. This limits the axial force to the value of the
6. Subsurface Loading on Manhole Riser
frictional force.
6.1 Performance Limits—The manhole riser’s performance
6.2.2.1 Downdrag loads can be calculated using finite ele-
limits include ring deflection, ring (hoop) and axial stress (or
ment methods, field measurements, or other procedures. In lieu
strain), and ring and axial buckling. Radially directed loads
of these, the following method may be used.The average shear
acting on a manhole cause ring deformation and ring bending
stress is given by Eq 3, for an active earth pressure distribution
stresses.Theradialloadvariesalongthelengthofthemanhole.
as shown in Fig. 2.
See Fig. 2. In addition to radial stresses, considerable axial
P 1P
R1 R2
stress may exist in the manhole wall as a result of “downdrag”.
T 5 µ (3)
F G
A
Downdrag occurs as the backfill soil surrounding the manhole
consolidates and settles. Axial load is induced through the where:
frictional resistance of the manhole to the backfill settlement.
T = average shear (frictional) stress, psf (kPa),
A
See Fig. 3. The manhole must also be checked for axial
P = radial earth pressure at top of manhole, psf (kPa),
R1
compressive stress and axial buckling due to downdrag forces. P = radial earth pressure at bottom of manhole, psf (kPa),
R2
and
6.2 Earth Pressure Acting on Manhole Riser:
µ = coefficient of friction between manhole and soil.
6.2.1 Radial Pressure—Radial pressure along the length of
the manhole riser may be calculated using finite element 6.2.2.2 The coefficient of friction between an HDPE man-
methods, field measurements, or other suitable means. See
hole with an essentially smooth outer surface and a granular or
Hossain and Lytton (1). In lieu of the preceding, the active granular-cohesive soil can be taken as 0.4. See Swan et al. (5)
earth pressure modified for uneven soil compaction around the
and Martin et al. (6). In some applications the coefficient of
perimeter of the riser can be used. friction may be reduced by coating the exterior of the manhole
with bentonite or some other lubricant.
The boldface numbers given in parentheses refer to a list of references at the NOTE 3—The use of external stiffeners or open profiles to stiffen the
end of the text. riser greatly increases the downdrag load due to their impeding the
F1759 − 97 (2010)
settlement of soil beside the manhole. This has the effect of increasing the
6.3.3 Where partial saturation of the soil exists, that is
average shear stress in Eq 3. Where open profiles are used, the coefficient
where the groundwater level is below the ground surface but
of friction may equal or exceed 1.0.
above the manhole invert, the radial pressure can be found by
6.2.2.3 The downdrag creates an axial-directed load (down-
combining the pressure due to the soil above the groundwater
drag load) in the manhole wall that increases with depth. The levelandthepressuregiveninEq5duetothegroundwaterand
axial force developed on the manhole can be found by
the submerged soil. In this case, H' as given in Eq 6 should be
integrating the shear stress (or frictional stress) between the substituted for H in Eq 5. See Appendix X2.
manhole and soil over the height of the fill. This integration is
H' 5 H 2 Z (6)
equal to the product of the surface area of the manhole times
where:
the average shear stress acting on the surface. The maximum
downdrag force can be found using Eq 4. Whether or not to H = weight of manhole, ft (m), and
include surface vehicular loads in this term depends on the Z = distance to water from surface grade, ft (m).
manhole top design. See 7.3.
6.3.4 Radial pressure obtained with Eq 5 should not be used
D to calculate downdrag pressure as the groundwater does not
o
P 5 T π H (4)
S D
D A
12 carry shear and thus does not contribute to downdrag. Calcu-
latedowndragforcesassumingadryinstallationusingEq1for
where:
radial pressure as described in 6.2.1. Use either the dry weight
P =
...
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