ASTM A746-18(2022)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:A746 −18 (Reapproved 2022)
Standard Specification for
Ductile Iron Gravity Sewer Pipe
This standard is issued under the fixed designation A746; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
3,4
1. Scope 2.2 ANSI/AWWA Standards:
C104/A21.4Cement Mortar Lining for Ductile-Iron Pipe
1.1 This specification covers 4 to 64 in. ductile iron gravity
and Fittings
sewer pipe, centrifugally cast, with push-on joints. This speci-
C111/A21.11Rubber-Gasket Joints for Ductile-Iron Pres-
ficationmaybeusedforpipewithothertypesofjoints,asmay
sure Pipe and Fittings
be agreed upon at the time of purchase.
C150/A21.50Thickness Design of Ductile-Iron Pipe
1.2 This specification covers trench load design procedures
C600Installation of Ductile-Iron Water Mains and Their
for both cement-lined pipe and flexible-lined pipe. Maximum
Appurtenances
depth of cover tables are included for both types of linings.
2.3 ASCE Standards:
Manuals and Reports on Engineering Practice, No.
1.3 The values stated in inch-pound units are to be regarded
37,(WCPF Manual of Practice No. 9), “Design and
as standard. The values given in parentheses are mathematical
Construction of Sanitary and Storm Sewers”
conversions to SI units that are provided for information only
and are not considered standard. 2.4 AASHTO Standard:
AASHTO T 99Standard Method of Test for the Moisture-
1.4 This international standard was developed in accor-
DensityRelationsofSoilsUsinga5.5lb(2.5kg)Rammer
dance with internationally recognized principles on standard-
and a 12 in. (305 mm) Drop
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
3. Terminology
mendations issued by the World Trade Organization Technical
3.1 Symbols:
Barriers to Trade (TBT) Committee.
3.1.1 A—outside radius of pipe,
2. Referenced Documents
D
ft 5
2.1 ASTM Standards:
D2487Practice for Classification of Soils for Engineering D
inmetres 5
S D
Purposes (Unified Soil Classification System) 2000
2 2
D3282 Practice for Classification of Soils and Soil-
3.1.2 a—conversionfactor,lb/ft topsi=144(kN/m tokPa
Aggregate Mixtures for Highway Construction Purposes
=1)
E8/E8MTest Methods for Tension Testing of Metallic Ma-
3.1.3 B—1.5 ft (0.457 m)
terials
3.1.4 b—effective pipe length: 36 in. (0.914 m)
E23Test Methods for Notched Bar Impact Testing of Me-
tallic Materials 3.1.5 C—surface load factor, Table 1
3.1.6 D—outside diameter, in., Table 2
This specification is under the jurisdiction of ASTM Committee A04 on Iron
Castings and is the direct responsibility of Subcommittee A04.12 on Pipes and Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
Tubes. 4th Floor, New York, NY 10036, http://www.ansi.org.
Current edition approved Oct. 1, 2022. Published October 2022. Originally Available fromAmericanWaterWorksAssociation (AWWA), 6666W. Quincy
approved in 1977. Last previous edition approved in 2018 as A746–18. DOI: Ave., Denver, CO 80235, http://www.awwa.org.
10.1520/A0746-18R22. Available fromAmerican Society of Civil Engineers (ASCE), 1801Alexander
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Bell Dr., Reston, VA 20191, http://www.asce.org.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Available from American Association of State Highway and Transportation
Standards volume information, refer to the standard’s Document Summary page on Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,
the ASTM website. http://www.transportation.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A746−18 (2022)
TABLE 1 Surface Load Factors for Single Truck on Unpaved Road
Pipe Size – in.
Depth
of Cover, 3 4 6 8 10 12 14 16 18
ft
Surface Load Factor – C
2.5 0.0589 0.0713 0.1020 0.1328 0.1615 0.1901 0.2178 0.2443 0.2698
3 0.0437 0.0530 0.0759 0.0990 0.1207 0.1424 0.1637 0.1843 0.2044
4 0.0265 0.0321 0.0460 0.0602 0.0736 0.0871 0.1005 0.1136 0.1265
5 0.0176 0.0213 0.0306 0.0401 0.0490 0.0581 0.0672 0.0761 0.0849
6 0.0125 0.0151 0.0217 0.0284 0.0348 0.0413 0.0478 0.0542 0.0606
7 0.0093 0.0113 0.0162 0.0212 0.0260 0.0308 0.0357 0.0405 0.0453
8 0.0072 0.0087 0.0125 0.0164 0.0201 0.0238 0.0276 0.0313 0.0350
9 0.0057 0.0069 0.0099 0.0130 0.0160 0.0190 0.0219 0.0249 0.0279
10 0.0046 0.0056 0.0081 0.0106 0.0130 0.0154 0.0179 0.0203 0.0227
12 0.0032 0.0039 0.0056 0.0074 0.0091 0.0108 0.0125 0.0142 0.0159
14 0.0024 0.0029 0.0042 0.0055 0.0067 0.0080 0.0092 0.0105 0.0117
16 0.0018 0.0022 0.0032 0.0042 0.0051 0.0061 0.0071 0.0080 0.0090
20 0.0012 0.0014 0.0020 0.0027 0.0033 0.0039 0.0045 0.0052 0.0058
24 0.0008 0.0010 0.0014 0.0019 0.0023 0.0027 0.0032 0.0036 0.0040
28 0.0006 0.0007 0.0010 0.0014 0.0017 0.0020 0.0023 0.0026 0.0030
32 0.0005 0.0006 0.0008 0.0011 0.0013 0.0015 0.0018 0.0020 0.0023
Depth Pipe Size – in.
of Cover, 20 24 30 36 42 48 54 60 64
ft Surface Load Factor – C
2.5 0.2941 0.3390 0.3962 0.4437 0.4813 0.5115 0.5366 0.5488 0.5592
3 0.2237 0.2602 0.3085 0.3507 0.3857 0.4153 0.4412 0.4543 0.4657
4 0.1391 0.1635 0.1972 0.2284 0.2559 0.2808 0.3040 0.3164 0.3277
5 0.0936 0.1106 0.1347 0.1576 0.1786 0.1982 0.2173 0.2278 0.2377
6 0.0669 0.0793 0.0970 0.1143 0.1304 0.1458 0.1612 0.1698 0.1781
7 0.0500 0.0594 0.0730 0.0863 0.0988 0.1111 0.1235 0.1306 0.1374
8 0.0387 0.0461 0.0567 0.0672 0.0773 0.0871 0.0973 0.1031 0.1088
9 0.0309 0.0367 0.0453 0.0538 0.0620 0.0700 0.0784 0.0833 0.0880
10 0.0251 0.0299 0.0370 0.0440 0.0507 0.0574 0.0644 0.0685 0.0725
12 0.0176 0.0210 0.0259 0.0309 0.0357 0.0405 0.0456 0.0486 0.0515
14 0.0130 0.0155 0.0192 0.0229 0.0265 0.0301 0.0339 0.0362 0.0384
16 0.0100 0.0119 0.0147 0.0176 0.0204 0.0232 0.0262 0.0279 0.0297
20 0.0064 0.0076 0.0095 0.0113 0.0131 0.0149 0.0169 0.0181 0.0192
24 0.0045 0.0053 0.0066 0.0079 0.0091 0.0104 0.0118 0.0126 0.0134
28 0.0033 0.0039 0.0049 0.0058 0.0067 0.0077 0.0087 0.0093 0.0099
32 0.0025 0.0030 0.0037 0.0044 0.0052 0.0059 0.0067 0.0071 0.0076
A746−18 (2022)
TABLE 2 Nominal Thicknesses for Standard Pressure Classes of Ductile Iron Pipe
Pressure Class
Outside Diameter,
Size, in. 150 200 250 300 350
in. (mm)
Nominal Thickness, in. (mm)
A
3 3.96 (100.6) . . . . . . . . . . . . 0.25 (6.4)
A
4 4.80 (121.9) . . . . . . . . . . . . 0.25 (6.4)
A
6 6.90 (175.3) . . . . . . . . . . . . 0.25 (6.4)
A
8 9.05 (229.9) . . . . . . . . . . . . 0.25 (6.4)
10 11.10 (281.9) . . . . . . . . . . . . 0.26 (6.6)
12 13.20 (335.3) . . . . . . . . . . . . 0.28 (7.1)
14 15.30 (388.6) . . . . . . 0.28 (7.1) 0.30 (7.6) 0.31 (7.9)
16 17.40 (442.0) . . . . . . 0.30 (7.6) 0.32 (8.1) 0.34 (8.6)
18 19.50 (495.3) . . . . . . 0.31 (7.9) 0.34 (8.6) 0.36 (9.1)
20 21.60 (548.6) . . . . . . 0.33 (8.4) 0.36 (9.1) 0.38 (9.7)
24 25.80 (655.3) . . . 0.33 (8.4) 0.37 (9.4) 0.40 (10.2) 0.43 (10.9)
30 32.00 (812.8) 0.34 (8.6) 0.38 (9.7) 0.42 (10.7) 0.45 (11.4) 0.49 (12.4)
36 38.30 (972.8) 0.38 (9.7) 0.42 (10.7) 0.47 (11.9) 0.51 (12.9) 0.56 (14.2)
42 44.50 (1130.3) 0.41 (10.4) 0.47 (11.9) 0.52 (13.2) 0.57 (14.5) 0.63 (16.0)
48 50.80 (1290.3) 0.46 (11.7) 0.52 (13.2) 0.58 (14.7) 0.64 (16.3) 0.70 (17.8)
54 57.56 (1450.3) 0.51 (12.9) 0.58 (14.7) 0.65 (16.5) 0.72 (18.3) 0.79 (20.1)
60 61.61 (1564.9) 0.54 (13.7) 0.61 (15.5) 0.68 (17.3) 0.76 (19.3) 0.83 (21.1)
64 65.67 (1668.0) 0.56 (14.2) 0.64 (16.3) 0.72 (18.3) 0.80 (20.3) 0.87 (22.1)
A
Calculated thicknesses for these sizes and pressure ratings are less than those shown above. Presently, these are the lowest nominal thicknesses available in these
sizes.
6 6
3.1.7 E—modulus of elasticity, 24 × 10 psi (165.5 × 10 4.3 Unless otherwise specified, pipe shall have a nominal
kPa) lengthof18or20ft(5.5or6.1m).Amaximumof20%ofthe
total number of pipe of each size specified in an order may be
3.1.8 E'—modulus of soil reaction, psi, Table 3
furnishedasmuchas24in.(610mm)shorterthanthenominal
3.1.9 F—impact factor, 1.5
laying length, and an additional 10% may be furnished as
3.1.10 f—designbendingstress,48 000psi(331×10 kPa)
muchas6in.(152mm)shorterthanthenominallayinglength.
3.1.11 H—depth of cover, ft (m)
5. Tolerances or Permitted Variations
3.1.12 K —bending moment coefficient, Table 3
b
5.1 Dimensions—The spigot end, bell, and socket of the
3.1.13 K —deflection coefficient, Table 3
x
pipe and the accessories shall be gaged with suitable gages at
3.1.14 P—wheel load, 16 000 lb (7257 kg)
sufficiently frequent intervals to ensure that the dimensions
comply with the requirements of this specification. The small-
3.1.15 P —earth load, psi (kPa)
e
estinsidediameter(ID)ofthesocketsandtheoutsidediameter
3.1.16 P—truck load, psi (kPa)
t
(OD) of the spigot ends shall be tested with circular gages.
3.1.17 P —trench load, psi (kPa) = P + P
v e t
Othersocketdimensionsshallbegagedasmaybeappropriate.
3.1.18 R—reductionfactorwhichtakesintoaccountthefact
5.2 Thickness—Minus thickness tolerances of pipe shall not
that the part of the pipe directly below the wheels is aided in
exceed those shown in Table 5.
carryingthetruckloadbyadjacentpartsofthepipethatreceive
NOTE 1—An additional minus tolerance of 0.02 in. (0.5 mm) shall be
little or no load from the wheels, Table 4
permitted along the barrel of the pipe for a distance not to exceed 12 in.
3.1.19 t—net thickness, in. (mm)
(305 mm).
3.1.20 t —minimum manufacturing thickness, in., t + 0.08,
6. Coating and Lining
(in mm, t + 2.0)
6.1 Outside Coating—The outside coating for use under
3 3
3.1.21 w—soil weight, 120 lb/ft (18.85 kN/m )
normal conditions shall be a shop-applied coating approxi-
3.1.22 ∆X—design deflection, in. (mm),
mately 1 mil (0.025 mm) thick.The coating shall be applied to
the outside of all pipe, unless otherwise specified.The finished
@∆X 5 0.03D#,or @~∆X 5 0.05D! forflexiblelinings#
coating shall be continuous and smooth, neither brittle when
4. General Requirements cold nor sticky when exposed to the sun, and shall be strongly
adherent to the pipe.
4.1 ThepipeshallbeductileironinaccordancewithSection
9. 6.2 Cement-Mortar Linings—Unless otherwise specified,
the lining shall be cement-mortar in accordance with ANSI/
4.2 Push-on joints shall comply with all applicable require-
AWWA C104/A21.4.
ments ofANSI/AWWAC111/A21.11. Pipe with other types of
joints shall comply with the joint dimensions and weights 6.3 Special Linings—For severely aggressive wastes, other
agreed upon at the time of purchase, but in all other respects types of linings may be available. Such special linings shall be
shall fulfill the requirements of this specification. specified in the invitation for bids and on the purchase order.
A746−18 (2022)
A
TABLE 3 Design Values for Standard Laying Conditions
Bedding
B
Laying Condition Description E' psi K K
b x
Angle, °
C D
Flat-bottom trench loose backfill. 150 30 0.235 0.108
C
Flat-bottom trench. Backfill lightly consolidated to 300 45 0.210 0.105
centerline of pipe.
E
Pipe bedded in 4 in. (102 mm) min loose soil. Backfill 400 60 0.189 0.103
lightly consolidated to top of pipe.
Pipe bedded in sand, gravel, or crushed stone to depth of 500 90 0.157 0.096
⁄8 pipe diameter, 4 in. (102 mm) min. Backfill compacted
to top of pipe. (Approximately 80 percent Standard
F
Proctor, AASHTO T 99.)
Pipe bedded in compacted granular material to centerline of 700 150 0.128 0.085
pipe, 4 in. (102 mm) minimum under pipe. Compacted
G E
granular or select material to top of pipe. (Approxi-
mately 90 percent Standard Proctor, AASHTO T 99.)
Pipe bedded to the top of the pipe with angular graded 1500 150 0.128 0.085
1 1
stone ( ⁄4 to 1 ⁄2 in.) or well-graded gravel. Minimum under
pipe. Compact the angular graded stone or well-graded
gravel to top of pipe. (Approximately 95 percent Standard
Proctor, AASHTO T 99.)
Type “Deep Bury”
A
Consideration of the pipe-zone embedment conditions included in this table may be influenced by factors other than pipe strength. For additional information see
ANSI/AWWA C600, Standard for installation of Ductile-Iron Water Mains and Their Appurtenances.
B
1 psi = 6.894757 kPa.
C
Flat-bottom is defined as undisturbed earth.
D
For pipe 14 in. (350 mm) and larger, consideration should be given to use of laying conditions other than Type 1.
E
Loose soil or select material is defined as native soil excavated from the trench, free of rocks, foreign materials, and frozen earth.
F
American Association of State Highway and Transportation Officials, 444 N. Capitol Street, N.W., Suite 225, Washington, DC 20001.
G
Granular materials are defined per AASHTO Soil Classification System (Practice D2487), with the exception that gravel bedding and gravel backfill adjacent to the pipe
is limited to 2 in. maximum particle size per ANSI/AWWA C600.
A746−18 (2022)
TABLE 4 Reduction Factors (R) for Truck Load Calculations
Depth of Cover, ft (m)
4to7 >7 to 10
Size, in. <4 (1.2) >10 (3.0)
(1.2 to 2.1) (2.4 to 3.0)
Reduction Factor
3 to 12 1.00 1.00 1.00 1.00
14 0.92 1.00 1.00 1.00
16 0.88 0.95 1.00 1.00
18 0.85 0.90 1.00 1.00
20 0.83 0.90 0.95 1.00
24 to 30 0.81 0.85 0.95 1.00
36 to 64 0.80 0.85 0.90 1.00
TABLE 5 Allowances for Casting Tolerance
7.4 Step 4—Add the casting allowance.
Size, in. Casting Tolerance, in. (mm)
7.4.1 Add the casting allowance from Table 5 to the
3–8 0.05 (1.3) minimum manufacturing thickness t . The resulting thickness
10–12 0.06 (1.5)
is the total calculated thickness.
14–42 0.07 (1.8)
48 0.08 (2.0)
7.5 Step 5—Selection of nominal thickness and standard
54–64 0.09 (2.3)
pressure class.
7.5.1 Use the total calculated thickness from 7.4.1 to select
a standard pressure class thickness from Table 2. When the
calculatedthicknessisbetweentwonominalthicknesses,select
7. Pipe Design
the larger of the two. When specifying and ordering pipe,
7.1 Step 1—Design for trench load.
specifythepressureclasslistedinTable2correspondingtothis
7.1.1 Determinethetrenchload,P .Table6givesthetrench
v
nominal thickness.
load,includingtheearthload,P ,plusthetruckload,P,for2.5
e t
NOTE 2—On specific projects, manufacturers may be willing to furnish
to 32 ft (0.76 to 9.75 m) of cover.
pipe with thicknesses that fall between standard classes.
7.1.2 Determine the standard laying condition from the
descriptions in Table 3 and select the appropriate table for
7.6 Alternative Procedure:
diameter-thickness ratios from Tables 7-12. Each table lists
7.6.1 The appropriate standard pressure class may also be
diameter-thickness ratios calculated for both bending and
determined by using the design equations in 7.9.
deflection over a range of trench loads.
7.7 Design Example—Calculate the thickness for 24 in.
7.1.3 Refer to the column headed “Bending-Stress Design”
(610 mm) cement-lined ductile iron pipe bedded in loose soil
intheappropriatetableofTables7-12,andlocatethetabulated
for a minimum depth of 4 in. (100 mm), backfill lightly
trench load P from 7.1.1. If the calculated P is halfway
v v
consolidatedtothetopofpipe,LayingConditionType3,under
between two tabulated values, use the larger P value. Select
v
10 ft (3 m) of cover.
the corresponding D/t value for this P . Divide the pipe’s
v
7.7.1 Step 1—Design for trench load.
outside diameter D (Table 2)bythe D/t value to obtain the net
7.7.1.1
thickness t required for bending stress design.
Earth load, Table 6, P = 10.0 psi
e
7.2 Step 2—Addition of service allowance.
Truck load, Table 6, P = 0.5 psi
t
Trench load, P = P + P = 10.5 psi
7.2.1 Add the service allowance of 0.08 in. (2.0 mm) to the v e t
net thickness t. The resulting thickness is the minimum
7.7.1.2 Select Table 9 for diameter-thickness ratios for
thickness t .
laying condition Type 3.
7.7.1.3 EnteringP of10.5psiinTable9,thebending-stress
7.3 Step 3—Check deflection.
v
design requires D/t of 144. From Table 2, diameter D of 24 in.
7.3.1 Refer to the column headed “Deflection Check” in the
pipe is 25.80 in.
appropriatetableofTables7-12andlocatethetabulatedtrench
load P from 7.1.1. If the calculated P is between two Net thickness, t, for bending stress = D/(D/t) = 25.80 / 144
v v
= 0.18 in.
tabulated values, use the larger P value. (If the calculated P
v v
is less than the minimum P listed in the table, the deflection 7.7.2 Step 2—Addition of service allowances.
v
does not govern—proceed to Step 4.) Select the corresponding 7.7.2.1 Net thickness is given by the design for trench load,
D/t value for this P . Divide the pipe’s outside diameter D
Step 1, or 0.18 in.
1 v
(Table 2)bythe D/t value to obtain the minimum thickness t
1 1 Net thickness = 0.18 in.
required for deflection. Compare this value to the required Service allowance = 0.08 in.
Minimum manfacturing thickness = 0.26 in.
minimum thickness t from 7.2.1.Ifthe t required for
1 1
deflectionislessthanthet from7.2.1,thendeflectiondoesnot 7.7.3 Step 3—Check deflection.
govern—proceed to Step 4. If the t required for deflection is 7.7.3.1 Entering P of 10.5 psi in Table 9, the “Deflection
1 v
greater than the t from 7.2.1, then deflection governs and the Check” requires D/t of 118. Minimum thickness t for
1 1 1
minimumthickness t requiredfordeflectionshouldbeusedin deflection design = D/(D/t ) = 25.80/118 = 0.22 in. This
1 1
Step 4. minimum thickness, 0.22 in., is less than the minimum
A746−18 (2022)
A
TABLE 6 Earth Loads (P ) Truck Loads (P) and Trench Loads (P ), psi
e t v
Depth of 3 in. Pipe 4 in. Pipe 6 in. Pipe 8 in. Pipe 10 in. Pipe 12 in. Pipe 14 in. Pipe 16 in. Pipe 18 in. Pipe 20 in. Pipe
P
e
Cover, ft (m) P P P P P P P P P P P P P P P P P P P P
t v t v t v t v t v t v t v t v t v t v
2.5 (0.8) 2.1 9.9 12.0 9.9 12.0 9.9 12.0 9.8 11.9 9.7 11.8 9.6 11.7 8.7 10.8 8.2 10.3 7.8 9.9 7.5 9.6
3 (0.9) 2.5 7.4 9.9 7.4 9.9 7.3 9.8 7.3 9.8 7.2 9.7 7.2 9.7 6.6 9.1 6.2 8.7 5.9 8.4 5.7 8.2
4 (1.2) 3.3 4.4 7.7 4.5 7.8 4.4 7.7 4.4 7.7 4.4 7.7 4.4 7.7 4.4 7.7 4.1 7.4 3.9 7.2 3.9 7.2
5 (1.5) 4.2 3.0 7.2 3.0 7.2 3.0 7.2 3.0 7.2 2.9 7.1 2.9 7.1 2.9 7.1 2.8 7.0 2.6 6.8 2.6 6.8
6 (1.8) 5.0 2.1 7.1 2.1 7.1 2.1 7.1 2.1 7.1 2.1 7.1 2.1 7.1 2.1 7.1 2.0 7.0 1.9 6.9 1.9 6.9
7 (2.1) 5.8 1.6 7.4 1.6 7.4 1.6 7.4 1.6 7.4 1.6 7.4 1.6 7.4 1.6 7.4 1.5 7.3 1.4 7.2 1.4 7.2
8 (2.4) 6.7 1.2 7.9 1.2 7.9 1.2 7.9 1.2 7.9 1.2 7.9 1.2 7.9 1.2 7.9 1.2 7.9 1.2 7.9 1.1 7.8
9 (2.7) 7.5 1.0 8.5 1.0 8.5 1.0 8.5 1.0 8.5 1.0 8.5 1.0 8.5 1.0 8.5 1.0 8.5 1.0 8.5 0.9 8.4
10 (3.0) 8.3 0.8 9.1 0.8 9.1 0.8 9.1 0.8 9.1 0.8 9.1 0.8 9.1 0.8 9.1 0.8 9.1 0.8 9.1 0.7 9.0
12 (3.7) 10.0 0.6 10.6 0.6 10.6 0.6 10.6 0.6 10.6 0.5 10.5 0.5 10.5 0.5 10.5 0.5 10.5 0.5 10.5 0.5 10.5
14 (4.3) 11.7 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1
16 (4.9) 13.3 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6
20 (6.1) 16.7 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9
24 (7.3) 20.0 0.2 20.2 0.1 20.1 0.1 20.1 0.1 20.1 0.1 20.1 0.1 20.1 0.1 20.1 0.1 20.1 0.1 20.1 0.1 20.1
28 (8.5) 23.3 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4
32 (9.8) 26.7 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8
Depth of 24 in. Pipe 30 in. Pipe 36 in. Pipe 42 in. Pipe 48 in. Pipe 54 in. Pipe 60 in. Pipe 64 in. Pipe
P
e
Cover, ft (m) P P P P P P P P P P P P P P P P
t v t v t v t v t v t v t v t v
2.5 (0.8) 2.1 7.1 9.2 6.7 8.8 6.2 8.3 5.8 7.9 5.4 7.5 5.0 7.1 4.8 6.9 4.5 6.6
3 (0.9) 2.5 5.4 7.9 5.2 7.7 4.9 7.4 4.6 7.1 4.4 6.9 4.1 6.6 3.9 6.4 3.8 6.3
4 (1.2) 3.3 3.6 6.9 3.5 6.8 3.4 6.7 3.3 6.6 3.1 6.4 3.0 6.3 2.9 6.2 2.8 6.1
5 (1.5) 4.2 2.4 6.6 2.4 6.6 2.3 6.5 2.3 6.5 2.2 6.4 2.1 6.3 2.1 6.3 2.1 6.3
6 (1.8) 5.0 1.7 6.7 1.7 6.7 1.7 6.7 1.7 6.7 1.6 6.6 1.6 6.6 1.6 6.6 1.5 6.5
7 (2.1) 5.8 1.3 7.1 1.3 7.1 1.3 7.1 1.3 7.1 1.2 7.0 1.2 7.0 1.2 7.0 1.2 7.0
8 (2.4) 6.7 1.1 7.8 1.1 7.8 1.1 7.8 1.0 7.7 1.0 7.7 1.0 7.7 1.0 7.7 1.0 7.7
9 (2.7) 7.5 0.9 8.4 0.9 8.4 0.8 8.3 0.8 8.3 0.8 8.3 0.8 8.3 0.8 8.3 0.8 8.3
10 (3.0) 8.3 0.7 9.0 0.7 9.0 0.7 9.0 0.7 9.0 0.7 9.0 0.7 9.0 0.7 9.0 0.7 9.0
12 (3.7) 10.0 0.5 10.5 0.5 10.5 0.5 10.5 0.5 10.5 0.5 10.5 0.5 10.5 0.5 10.5 0.5 10.5
14 (4.3) 11.7 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1 0.4 12.1
16 (4.9) 13.3 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6 0.3 13.6
20 (8.1) 16.7 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9 0.2 16.9
24 (7.3) 20.0 0.1 20.1 0.1 20.1 0.1 20.1 0.1 20.1 0.1 20.1 0.1 20.1 0.1 20.1 0.1 20.1
28 (8.5) 23.3 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4 0.1 23.4
32 (9.8) 26.7 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8 0.1 26.8
A
1 psi = 6.894757 kPa.
A746−18 (2022)
TABLE 7 Diameter-Thickness Ratios for Laying Condition
Type 1
A
NOTE 1—E' = 150 psi K = 0.235 K = 0.108
b x
A A
Trench Load P , psi Trench Load P , psi
v v
Deflection Check Deflection Check
Bending Bending
B B
D/t or D/t or
Stress C D Stress C D
3% 5% 3% 5%
D/t D/t
1 1
Design Design
max max max max
5.17 3.89 6.48 150 10.37 8.85 14.74 90
5.21 3.91 6.52 149 10.55 9.06 15.11 89
5.26 3.94 6.57 148 10.74 9.29 15.48 88
5.30 3.97 6.62 147 10.93 9.53 15.88 87
5.35 4.00 6.67 146 11.13 9.78 16.30 86
5.40 4.03 6.72 145 11.34 10.04 16.73 85
5.45 4.06 6.77 144 11.55 10.31 17.19 84
5.49 4.09 6.82 143 11.78 10.60 17.67 83
5.54 4.13 6.88 142 12.01 10.90 18.17 82
5.59 4.16 6.94 141 12.25 11.22 18.70 81
5.65 4.20 6.99 140 12.50 11.56 19.26 80
5.70 4.23 7.05 139 12.76 11.91 19.85 79
5.75 4.27 7.12 138 13.03 12.28 20.46 78
5.80 4.31 7.18 137 13.31 12.67 21.11 77
5.86 4.35 7.25 136 13.60 13.08 21.79 76
5.91 4.39 7.31 135 13.91 13.51 22.52 75
5.97 4.43 7.38 134 14.23 13.97 23.28 74
6.03 4.47 7.46 133 14.56 14.45 24.08 73
6.09 4.52 7.53 132 14.91 14.96 24.93 72
6.15 4.56 7.61 131 15.27 15.50 25.83 71
6.21 4.61 7.69 130 15.65 16.07 26.78 70
6.27 4.66 7.77 129 16.05 16.68 27.79 69
6.33 4.71 7.85 128 16.46 17.32 28.86 68
6.40 4.76 7.94 127 16.89 18.00 30.00 67
6.46 4.82 8.03 126 17.35 18.73 31.21 66
6.53 4.87 8.12 125 17.83 19.50 32.49 65
6.60 4.93 8.22 124 18.33 20.32 33.86 64
6.67 4.99 8.32 123 18.85 21.19 35.32 63
6.74 5.05 8.42 122 19.40 22.12 36.87 62
6.82 5.11 8.52 121 19.98 23.12 38.53 61
6.89 5.18 8.63 120 20.59 24.18 40.30 60
6.97 5.25 8.74 119 21.23 25.32 42.20 59
7.05 5.32 8.86 118 21.91 26.54 44.23 58
7.13 5.39 8.98 117 22.63 27.85 46.42 57
7.21 5.46 9.11 116 23.38 29.26 48.76 56
7.29 5.54 9.24 115 24.18 30.77 51.28 55
7.38 5.62 9.37 114 25.02 32.39 53.99 54
7.47 5.71 9.51 113 25.92 34.15 56.92 53
7.56 5.79 9.65 112 26.86 36.05 60.08 52
7.65 5.88 9.80 111 27.87 38.10 63.50 51
7.75 5.97 9.96 110 28.94 40.32 67.20 50
7.85 6.07 10.12 109 30.07 42.73 71.22 49
7.95 6.17 10.28 108 31.28 45.35 75.58 48
8.05 6.27 10.46 107 32.57 48.20 80.34 47
8.16 6.38 10.63 106 33.95 51.31 85.52 46
8.27 6.49 10.82 105 35.42 54.72 91.19 45
8.38 6.61 11.01 104 37.00 58.44 97.40 44
8.49 6.73 11.22 103 38.69 62.53 104.22 43
8.61 6.86 11.43 102 40.50 67.03 111.71 42
8.74 6.99 11.64 101 42.46 71.99 119.98 41
8.86 7.12 11.87 100 44.56 77.47 129.11 40
8.99 7.26 12.11 99 46.84 83.54 139.23 39
9.13 7.41 12.35 98 49.30 90.28 150.47 38
9.27 7.57 12.61 97 51.96 97.80 163.00 37
9.41 7.73 12.88 96 54.86 106.20 177.00 36
9.56 7.89 13.15 95 58.02 115.62 192.70 35
9.71 8.07 13.45 94 61.46 126.21 210.36 34
9.87 8.25 13.75 93 65.23 138.18 230.29 33
A746−18 (2022)
TABLE7 Continued
A A
Trench Load P , psi Trench Load P , psi
v v
Deflection Check Deflection Check
Bending Bending
B B
D/t or D/t or
Stress C D Stress C D
3% 5% 3% 5%
D/t D/t
1 1
Design max max Design max max
10.03 8.44 14.07 92 69.36 151.73 252.88 32
10.20 8.64 14.40 91 73.92 167.15 278.58 31
78.94 184.77 307.96 30
A
1 psi = 6.894757 kPa.
B
The D/t for the tabulated P nearest to the calculated P is selected. When the
v v
calculated P is halfway between two tabulated values, the smaller D/t should be
v
used.
C
Maximum 3 % deflection is recommended for rigid or semirigid linings such as
cement mortar.
D
Maximum 5 % deflection is recommended for flexible linings such as asphaltic
and plastic.
thickness calculated in 7.7.2.1 above (0.26 in.); therefore, factor. The surface load factors in Table 1 were calculated by
deflection does not govern. Eq 5 for a single concentrated wheel load centered over an
7.7.4 Step 4—Add the casting allowance. effective pipe length of 3 ft (0.91 m).
7.7.4.1
7.8.9 Design for Trench Load—Tables 7-12, the diameter-
thickness ratios tables used to design for trench load, were
Minimum manufacturing thickness = 0.26 in.
Casting allowance = 0.07 in.
computed by Eq 1 and 2. Eq 1 is based on the bending stress
Total calculated thickness = 0.33 in.
at the bottom of the pipe. The design bending stress, f,is
7.7.5 Step 5—Selection of nominal thickness and standard
48 000 psi (331 MPa) which provides at least a 1.5 safety
pressure class.
factor based on minimum ring yield strength and 2.0 safety
7.7.5.1 The total calculated thickness of 0.33 in. is the same
factor based on ultimate strength. Eq 2 is based on the
as 0.33in., Class 200, in Table 2. Therefore, Class 200
deflection of the pipe ring section. The design deflection ∆ is
x
(0.33in.) is selected for specifying and ordering.
3% of the outside diameter of the pipe for cement-lined pipe
and 5% for pipe with flexible linings. Design values of the
7.8 Design Method:
trench parameters, E', K , and K are given in Table 3.
7.8.1 Calculations are made for the thickness required to
b x
resist the bending stress caused by trench load. 7.8.10 Tables similar to Tables 7-12 may be compiled for
7.8.2 To this net thickness is added a service allowance to
laying conditions other than those shown in this specification
obtain the minimum thickness t . by calculating the trench loads, P , for a series of diameter-
1 v
7.8.3 Theminimumthicknessrequiredfordeflectionisthen
thickness ratios, D/t and D/t , using Eq 1 and 2 with values of
calculatedandcomparedto t .Thelargerofthetwoisselected E', K , and K appropriate to the bedding and backfill condi-
1 b x
as the minimum manufacturing thickness. To this minimum
tions.
manufacturingthicknessisaddedacastingallowancetoobtain
7.9 Design Equations:
the total calculated thickness.
f
7.8.4 The nominal thickness and the standard pressure class
P 5 (1)
v
K
D D
for specifying and ordering are selected from the table of x
3 2 1 K 2
S DS D
b
t t 8E
nominal thicknesses for standard pressure classes (Table 2).
10.732
D
7.8.5 The reverse of the above procedure is used to deter-
3 4
E' 2 1
S D
t
mine the maximum depth of cover for pipe of a given pressure
class.
∆X
7.8.6 Trench Load, P —Trench load is expressed as vertical
v D 8E
P 5 1.732E' (2)
pressure, psi, and is equal to the sum of earth load, P , and v 3
e
12K D
x
F G
2 1
S D
truck load, P.
t t
7.8.7 Earth Load, P —Earth load is computed by Eq 3 for
e
wH
the weight of the unit prism of soil with a height equal to the
P 5 (3)
e
a
distancefromthetopofthepipetothegroundsurface.Theunit
3 3
CP
weight of backfill soil is taken to be 120 lb/ft (18.85 kN/m ).
P 5 RF (4)
t
bD
If the designer anticipates additional loads, the design load
should be increased accordingly.
2 2 2
2 A 1B 1H
7.8.8 Truck Load, P—The truck loads shown in Table 6 C 5 1 2 arcsinF HŒ G (5)
t 2 2 2 2
π ~ A 1H !~ H 1B !
were computed by Eq 4 using the surface load factors in Table
2 A·H·B 1 1
1 and the reduction factor R from Table 4 for a single
1 1
S D
2 2 2 2
S D
π 2 2 2 A 1H B 1H
AASHTO H-20 truck on an unpaved road or flexible =A 1H 1B
pavement, 16 000 lbf (71 kN) wheel load and 1.5 impact NOTE 3—In Eq 5, angles are in radians.
A746−18 (2022)
TABLE 8 Diameter-Thickness Ratios for Laying Condition
Type 2
A
NOTE 1—E' = 300 psi K = 0.210 K = 0.105
b x
A A
Trench Load P , psi Trench Load P , psi
v v
Deflection Check Deflection Check
Bending Bending
B B
D/t or D/t or
Stress C D Stress C D
3% 5% 3% 5%
D/t D/t
1 1
Design Design
max max max max
7.42 6.61 11.02 150 13.68 11.71 19.52 90
7.48 6.64 11.06 149 13.88 11.94 19.89 89
7.54 6.67 11.11 148 14.08 12.17 20.28 88
7.61 6.70 11.16 147 14.30 12.42 20.69 87
7.67 6.73 11.21 146 14.51 12.67 21.12 86
7.74 6.76 11.27 145 14.74 12.94 21.57 85
7.80 6.79 11.32 144 14.97 13.22 22.04 84
7.87 6.83 11.38 143 15.21 13.52 22.53 83
7.94 6.86 11.43 142 15.46 13.83 23.05 82
8.01 6.89 11.49 141 15.72 14.16 23.60 81
8.08 6.93 11.55 140 15.99 14.50 24.17 80
8.15 6.97 11.61 139 16.28 14.86 24.77 79
8.22 7.01 11.68 138 16.57 15.24 25.40 78
8.29 7.05 11.74 137 16.87 15.64 26.07 77
8.37 7.09 11.81 136 17.19 16.06 26.77 76
8.44 7.13 11.88 135 17.52 16.51 27.52 75
8.52 7.17 11.95 134 17.86 16.98 28.30 74
8.59 7.22 12.03 133 18.22 17.48 29.13 73
8.67 7.26 12.10 132 18.59 18.00 30.00 72
8.75 7.31 12.18 131 18.98 18.56 30.93 71
8.83 7.36 12.26 130 19.39 19.14 31.91 70
8.91 7.41 12.35 129 19.82 19.77 32.95 69
8.99 7.46 12.43 128 20.27 20.43 34.05 68
9.07 7.51 12.52 127 20.73 21.13 35.22 67
9.16 7.57 12.62 126 21.23 21.87 36.46 66
9.25 7.63 12.71 125 21.74 22.67 37.78 65
9.33 7.69 12.81 124 22.28 23.51 39.18 64
9.42 7.75 12.91 123 22.85 24.41 40.68 63
9.51 7.81 13.02 122 23.45 25.37 42.28 62
9.60 7.87 13.12 121 24.07 26.39 43.99 61
9.70 7.94 13.24 120 24.74 27.49 45.81 60
9.79 8.01 13.35 119 25.43 28.66 47.76 59
9.89 8.08 13.47 118 26.17 29.91 49.86 58
9.99 8.16 13.60 117 26.95 31.26 52.10 57
10.09 8.23 13.72 116 27.77 32.71 54.51 56
10.19 8.31 13.86 115 28.64 34.26 57.10 55
10.29 8.40 13.99 114 29.56 35.93 59.89 54
10.40 8.48 14.14 113 30.53 37.74 62.90 53
10.51 8.57 14.29 112 31.57 39.69 66.15 52
10.62 8.66 14.44 111 32.67 41.80 69.67 51
10.73 8.76 14.60 110 33.84 44.09 73.48 50
10.84 8.86 14.76 109 35.08 46.56 77.61 49
10.96 8.96 14.93 108 36.41 49.26 82.10 48
11.08 9.07 15.11 107 37.83 52.19 86.99 47
11.21 9.18 15.30 106 39.34 55.40 92.33 46
11.33 9.29 15.49 105 40.96 58.89 98.16 45
11.46 9.41 15.69 104 42.70 62.73 104.54 44
11.59 9.54 15.89 103 44.57 66.93 111.55 43
11.73 9.67 16.11 102 46.57 71.56 119.26 42
11.87 9.80 16.33 101 48.73 76.66 127.76 41
12.01 9.94 16.57 100 51.06 82.29 137.16 40
12.16 10.09 16.81 99 53.57 88.54 147.57 39
12.31 10.24 17.06 98 56.30 95.48 159.13 38
12.46 10.40 17.33 97 59.25 103.21 172.02 37
12.62 10.56 17.60 96 62.46 111.85 186.42 36
12.79 10.73 17.89 95 65.96 121.54 202.56 35
12.96 10.91 18.19 94 69.79 132.44 220.73 34
13.13 11.10 18.50 93 73.98 144.74 241.23 33
A746−18 (2022)
TABLE8 Continued
A A
Trench Load P , psi Trench Load P , psi
v v
Deflection Check Deflection Check
Bending Bending
B B
D/t or D/t or
Stress C D Stress C D
3% 5% 3% 5%
D/t D/t
1 1
Design max max Design max max
13.31 11.29 18.82 92 78.57 158.68 264.46 32
13.49 11.50 19.17 91 83.64 174.54 290.90 31
89.23 192.67 321.11 30
A
1 psi = 6.894757 kPa.
B
The D/t for the tabulated P nearest to the calculated P is selected. When the
v v
calculated P is halfway between two tabulated values, the smaller D/t should be
v
used.
C
Maximum 3 % deflection is recommended for rigid or semirigid linings such as
cement mortar.
D
Maximum 5 % deflection is recommended for flexible linings such as asphaltic
and plastic.
8. Hydrostatic Test thepipewallthicknessexceeds0.40in.(10.2mm),theCharpy
impact specimen may be machined to a nominal thickness of
8.1 Each pipe shall be subjected to a hydrostatic test of not
0.40 in. In all tests, impact values are to be corrected to a
lessthan500psi(3.45MPa).Thistestmaybeperformedeither
standard wall thickness, t = 0.40 in., by calculation as
s
beforeoraftertheoutsidecoatingandinsidecoatinghavebeen
follows:
applied, but shall be performed before the application of
cement-mortar lining or of a special lining. t
s
Impactvalue corrected 5 3impactvalue actual
~ ! ~ !
t
8.2 The pipe shall be under the full test pressure for at least
5 s. Suitable controls and recording devices shall be provided
where: t = the thickness of the specimen, in. (mm).
so that the test pressure and duration are adequately ascer-
The Charpy impact test machine anvil shall not be moved to
tained. Any pipe that leaks or does not withstand the test
compensateforthevariationofcross-sectiondimensionsofthe
pressure shall be rejected.
test specimens.
9.3.1 Acceptance Value—The corrected acceptance value
8.3 Inadditiontothehydrostatictestbeforeapplicationofa
for notched impact test specimens shall be a minimum of
cement-mortar lining or special lining, the pipe may be
7ft·lbf (9.49 J) for tests conducted at 70 6 10°F (21 6 6°C).
retested, at the manufacturer’s option, after the application of
such a lining.
9.4 Sampling—At least one tension sample shall be taken
during each casting pe
...