ASTM C1479-16(2021)

Standard Practice for Installation of Precast Concrete Sewer, Storm Drain, and Culvert Pipe Using Standard Installations

SIGNIFICANCE AND USE
4.1 This practice is useful as a reference by an owner and the owner's engineer in preparing project specifications.
SCOPE
1.1 This practice covers the installation of precast concrete pipe intended to be used for the conveyance of sewage, industrial wastes, and storm water and for the construction of culverts.  
1.2 This practice is the inch-pound companion to Practice C1479M; therefore, no SI equivalents are presented in this practice.  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

General Information

• Status: Historical
• Publication Date: 31-Dec-2020
• ICS: 23.040.50 - Pipes and fittings of other materials
• Technical Committee: C13 - Concrete Pipe
• Drafting Committee: C13.05 - Special Projects

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C1479 − 16 (Reapproved 2021)
Standard Practice for
Installation of Precast Concrete Sewer, Storm Drain, and
Culvert Pipe Using Standard Installations
This standard is issued under the fixed designation C1479; 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 D1557 Test Methods for Laboratory Compaction Character-
istics of Soil Using Modified Effort (56,000 ft-lbf/ft
1.1 This practice covers the installation of precast concrete
(2,700 kN-m/m ))
pipe intended to be used for the conveyance of sewage,
D2487 Practice for Classification of Soils for Engineering
industrial wastes, and storm water and for the construction of
Purposes (Unified Soil Classification System)
culverts.
D2488 Practice for Description and Identification of Soils
1.2 This practice is the inch-pound companion to Practice
(Visual-Manual Procedures)
C1479M; therefore, no SI equivalents are presented in this
IEEE/ASTM SI 10 Standard for Use of the International
practice.
System of Units (SI): The Modern Metric System
1.3 This standard does not purport to address all of the
2.2 AASHTO Standards:
safety concerns, if any, associated with its use. It is the
Standard Specifications for Highway Bridges
responsibility of the user of this standard to establish appro-
M 145 Classification of Soils and Soil—Aggregate Mixtures
priate safety, health, and environmental practices and deter-
for Highway Construction Purposes
mine the applicability of regulatory limitations prior to use.
T99 The Moisture-Density Relations of Soils Using a 5.5 lb
1.4 This international standard was developed in accor-
(2.5 kg) Rammer and a 12-in. (305 mm) Drop
dance with internationally recognized principles on standard-
T 180 TheMoisture-DensityRelationsofSoilsUsinga10lb
ization established in the Decision on Principles for the
(4.54 kg) Rammer and an 18-in. (457 mm) Drop
Development of International Standards, Guides and Recom-
T 310 In-Place Density and Moisture Content of Soil and
mendations issued by the World Trade Organization Technical
Soil—Aggregate by Nuclear Methods (Shallow Depth)
Barriers to Trade (TBT) Committee.
2.3 ASCE Standards:
ASCE 15 Standard Practice for the Direct Design of Buried
2. Referenced Documents
Precast Reinforced Concrete Pipe Using Standard Instal-
2.1 ASTM Standards:
lations (SIDD)
C822 Terminology Relating to Concrete Pipe and Related
3. Terminology
Products
C1417 Specification for Manufacture of Reinforced Con-
3.1 For definitions of terms relating to concrete pipe, see
crete Sewer, Storm Drain, and Culvert Pipe for Direct
Terminology C822.
Design
3.2 For terminology related to soil classifications, see Prac-
C1479M Practice for Installation of Precast Concrete Sewer,
tice D2487 and Practice D2488.
Storm Drain, and Culvert Pipe Using Standard Installa-
3.3 For terminology and definitions of terms relating to
tions (Metric)
structural design, see ASCE 15.
D698 Test Methods for Laboratory Compaction Character-
istics of Soil Using Standard Effort (12,400 ft-lbf/ft (600
3.4 Fig. 1 illustrates the definitions and limits of the terms:
kN-m/m ))
foundation, subgrade, bedding, outer bedding, middle bedding,
haunch, lower side, backfill or overfill, invert, crown,
springline, top of pipe, and bottom of pipe as used in this
This practice is under the jurisdiction of ASTM Committee C13 on Concrete
practice.
Pipe and is the direct responsibility of Subcommittee C13.05 on Special Projects.
Current edition approved Jan. 1, 2021. Published January 2021. Originally
approved in 2000. Last previous edition approved in 2016 as C1479 - 16. DOI:
10.1520/C1479-16R21. Available from American Association of State Highway and Transportation
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM http://www.transportation.org.
Standards volume information, refer to the standard’s Document Summary page on Available from American Society of Civil Engineers (ASCE), 1801 Alexander
the ASTM website. Bell Dr., Reston, VA 20191, http://www.asce.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1479 − 16 (2021)
FIG. 1 Pipe/Installation Terminology
4. Significance and Use 7.2 Where surface water or groundwater conditions exist,
the site and trench shall be dewatered.
4.1 This practice is useful as a reference by an owner and
the owner’s engineer in preparing project specifications.
8. Foundation
5. Notations
8.1 The foundation shall be moderately firm to hard in situ
soil, stabilized soil, or compacted fill material.
D = inside diameter of pipe, in.
i
D = outside diameter of pipe, in. 8.2 When unsuitable or unstable material is encountered,
o
H = design height of earth above top of pipe, ft. the foundation shall be stabilized.
w = unit weight of soil, lb/ft .
8.3 Methods to prevent migration of soil fines shall be
provided when groundwater or existing soil conditions are
6. Standard Installations
conducive to particle migration. Gravelly soils, with little or no
6.1 The precast concrete pipe/soil system shall be con-
fines, could migrate under certain conditions, causing lack of
structed to conform to the requirements of Figs. 2 and 3 and
support.
Tables 1 and 2 as designated on the plans.
8.4 Pipe installed over an unyielding foundation shall be
7. Excavation
cushioned so as to prevent blasting shock when future blasting
is anticipated in the area.
7.1 When rock or other unyielding foundation material is
encountered, it shall be removed at least to the requirements
9. Bedding
shown in Figs. 2 and 3 and Tables 1 and 2. Overexcavated
areas shall be backfilled with approved materials and com- 9.1 Thebeddingshallbeconstructeduniformlyoverthefull
pacted to at least the standard proctor density specified for the length of the pipe barrel, as required for the designated
bedding. standard installation, to distribute the loadbearing reaction
C1479 − 16 (2021)
FIG. 2 Standard Embankment Installations
NOTE 1—Clearance between pipe and trench wall shall be adequate to enable specified compaction but not less than D /6.
o
FIG. 3 Standard Trench Installations
C1479 − 16 (2021)
TABLE 1 Standard Embankment Installation Soils and Minimum Compaction Requirements
NOTE 1—Compaction and soil symbols (that is, 95 % Category I) refer to a soil material category with a minimum standard proctor density. See Table
3 for equivalent modified proctor values and soil types.
NOTE 2—Type 1 installations require greater soil stiffness from the surrounding soils than the Type 2, 3, and 4 installations. Proper field verification
of soil properties and compaction levels must be performed to ensure compliance with the design requirements. See Appendix X2 for more information
and guidance.
NOTE 3—For Type 1 installation, crushed rock is not an appropriate material for bedding under the pipe.An uncompacted, non-crushed material must
beusedunderthemiddlethirdofthepipeoutsidediameter.Whilecrushedrockmeetingtherequirementsofthisspecificationmayselfcompactvertically,
it will not flow laterally to provide support for the haunches of the pipe. To achieve a 90 to 95 % compaction with crushed rock, work material under
the haunch and compact it to achieve the specified density. Otherwise, the specified installation is not achieved.
NOTE 4—Soil in the outer bedding, haunch, and lower side zones, except within D /3 from the pipe springline, shall be compacted to at least the same
o
compaction as the majority of soil in the overfill zone.
NOTE 5—Required bedding thickness is the thickness of the bedding prior to placement of the pipe.
NOTE 6—Asubtrench is defined as a trench with its top below finished grade by more than 0.1 H or, for roadways, its top is at an elevation lower than
1 ft below the bottom of the pavement base material.
The minimum width of a subtrench shall be 1.33 D , or wider, if required for adequate space to attain the specified compaction in the haunch and
o
bedding zones.
Forsubtrenches,exceptwithinD /3fromthespringline,anyportionofthelowersidezoneinthesubtrenchwallshallbeatleastasfirmasanequivalent
o
soil placed to the compaction requirements specified for the lower side zone and as firm as the majority of soil in the overfill zone, or it shall be removed
and replaced with soil compacted to the specified level.
NOTE 7—“Dumped” material without additional compactive effort will not provide the design haunch support required for Type 1 and 2 installations.
Installation Bedding Haunch and Lower
Type Thickness Outer Bedding Side
Type 1 D /24 minimum; not less than 3 in. If rock 95 % Category I 90 % Category I,
o
foundation, use D /12 minimum; not less than 6 95 % Category II
o
in.
Type 2 D /24 minimum; not less than 3 in. If rock 90 % Category I or 85 % Category I,
o
foundation, use D /12 minimum; not less than 6 95 % Category II 90 % Category II,
o
in. or 95 % Category III
Type 3 D /24 minimum; not less than 3 in. If rock 85 % Category I, 85 % Category I,
o
foundation, use D /12 minimum; not less than 6 90 % Category II, or 90 % Category II, or
o
in. 95 % Category III 95 % Category III
Type 4 No bedding required, except if rock foundation, No compaction required, No compaction required,
use D /12 minimum; not less than 6 in. except if Category III, except if Category III,
o
use 85 % Category III use 85 % Category III
uniformly on the pipe barrel over its full length, and to 9.6 Bell holes shall be excavated in the bedding or
maintaintherequiredpipegrade.SeeFig.4.Ifplacedinlayers, foundation, or both, when installing pipe with expanded bells
the thickness of the layers shall be as required to achieve the so that the pipe is supported by the barrel and not by the bells.
specified compaction and as required by the project specifica-
See Fig. 4.
tions.
9.7 Any outer bedding under the lower side areas shall be
9.2 The bedding layers for standard installation Types 1, 2,
compacted to at least the same requirements as for the lower
and 3 shall be placed to be as uniform as possible, but shall be side areas.
loosely placed uncompacted material under the middle third of
the pipe prior to placement of the pipe.
10. Pipe Placement and Joining
9.3 The maximum aggregate size shall be 1 in. when the
10.1 Pipe shall be installed to the line and grade shown on
bedding thickness is less than 6 in. and 1 ⁄2-in. when the
the project plans and specifications. The joint shall be as
bedding thickness is 6 in. or greater, except as noted in 9.4.
specified in the project specifications and shall be installed in
accordance with the pipe manufacturer’s recommendations.
9.4 When in situ soils conforming to project specifications
are used in constructing the outer bedding for Type 3 and 4
NOTE 1—(Advisory) Where practical, work should be started at the
installations, the maximum aggregate size shall not be greater lowest end of the pipeline and the pipe laid with the bell end upgrade.
than 3 in., or half the bedding thickness, whichever is less.
10.2 If required, the top of the pipe section being laid shall
9.5 The use of aggregate sizes larger than 1 in. shall be be positioned to the correct rotational orientation and then
limited to 20 % of the bedding material by weight. joined.
C1479 − 16 (2021)
TABLE 2 Standard Trench Installation Soils and Minimum Compaction Requirements
NOTE 1—Compaction and soil symbols (that is, 95 % Category I) refer to a soil material category with a minimum standard proctor density. See Table
3 for equivalent modified proctor values and soil types.
NOTE 2—Type 1 installations require greater soil stiffness from the surrounding soils than the Type 2, 3, and 4 installations. Proper field verification
of soil properties and compaction levels must be performed to ensure compliance with the design requirements. See Appendix X2 for more information
and guidance.
NOTE 3—For Type 1 installation, crushed rock is not an appropriate material for bedding under the pipe.An uncompacted, non-crushed material must
beusedunderthemiddlethirdofthepipeoutsidediameter.Whilecrushedrockmeetingtherequirementsofthisspecificationmayselfcompactvertically,
it will not flow laterally to provide support for the haunches of the pipe. To achieve a 90 to 95 % compaction with crushed rock, work material under
the haunch and compact it to achieve the specified density. Otherwise, the specified installation is not achieved.
NOTE 4—When the trench width specified must be exceeded, the owner shall be notified.
NOTE 5—The trench width shall be wider than shown (Fig. 3) if required for adequate space to attain the specified compaction in the haunch and
bedding zones.
NOTE 6—Embankment loading shall be used when trench walls consist of embankment unless a geotechnical analysis is made and the soil in the trench
walls is compacted to a higher level than the soil in the backfill zone.
NOTE 7—Required bedding thickness is the thickness of the bedding prior to placement of the pipe.
NOTE 8—“Dumped” material without additional compactive effort will not provide the design haunch support required for Type 1 and 2 installations.
Installation Bedding Haunch and Lower
Type Thickness Outer Bedding Side
Type 1 D /24 minimum; not less than 3 in. If rock 95 % Category I Undisturbed natural soil with firmness equivalent to
o
foundation, use D /12 minimum; not less the following placed soils:
o
than 6 in. 90 % Category I,
95 % Category II,
or embankment to the same requirements
Type 2 D /24 minimum; not less than 3 in. If rock 90 % Category I or Undisturbed natural soil with firmness equivalent to
o
foundation, use D /12 minimum; not less 95 % Category II the following placed soils:
o
than 6 in. 85 % Category I,
90 % Category II,
95 % Category III,
or embankment to the same requirements
Type 3 D /24 minimum; not less than 3 in. If rock 85 % Category I, Undisturbed natural soil with firmness equivalent to
o
foundation, use D /12 minimum; not less 90 % Category II, the following placed soils:
o
than 6 in. or 95 % Category III 85 % Category I,
90 % Category II,
95 % Category III,
or embankment to the same requirements
Type 4 No bedding required, except if rock No compaction required, No compaction required,
foundation, use D /12 minimum; not less except if Category III, except if Category III,
o
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C1479 − 16 C1479 − 16 (Reapproved 2021)
Standard Practice for
Installation of Precast Concrete Sewer, Storm Drain, and
Culvert Pipe Using Standard Installations
This standard is issued under the fixed designation C1479; 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
1.1 This practice covers the installation of precast concrete pipe intended to be used for the conveyance of sewage, industrial
wastes, and storm water and for the construction of culverts.
1.2 This practice is the inch-pound companion to Practice C1479M; therefore, no SI equivalents are presented in this practice.
1.3 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 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.
2. Referenced Documents
2.1 ASTM Standards:
C822 Terminology Relating to Concrete Pipe and Related Products
C1417 Specification for Manufacture of Reinforced Concrete Sewer, Storm Drain, and Culvert Pipe for Direct Design
C1479M Practice for Installation of Precast Concrete Sewer, Storm Drain, and Culvert Pipe Using Standard Installations
(Metric)
3 3
D698 Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft (600 kN-m/m ))
D1557 Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft (2,700
kN-m/m ))
D2487 Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)
D2488 Practice for Description and Identification of Soils (Visual-Manual Procedures)
IEEE/ASTM SI 10 Standard for Use of the International System of Units (SI): The Modern Metric System
2.2 AASHTO Standards:
Standard Specifications for Highway Bridges
M 145 Classification of Soils and Soil—Aggregate Mixtures for Highway Construction Purposes
T 99 The Moisture-Density Relations of Soils Using a 5.5 lb (2.5 kg) Rammer and a 12-in. (305 mm) Drop
T 180 The Moisture-Density Relations of Soils Using a 10 lb (4.54 kg) Rammer and an 18-in. (457 mm) Drop
This practice is under the jurisdiction of ASTM Committee C13 on Concrete Pipe and is the direct responsibility of Subcommittee C13.05 on Special Projects.
Current edition approved Oct. 15, 2016Jan. 1, 2021. Published October 2016January 2021. Originally approved in 2000. Last previous edition approved in 20132016 as
C1479 - 13.C1479 - 16. DOI: 10.1520/C1479-16.10.1520/C1479-16R21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American Association of State Highway and Transportation Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,
http://www.transportation.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1479 − 16 (2021)
T 310 In-Place Density and Moisture Content of Soil and Soil—Aggregate by Nuclear Methods (Shallow Depth)
2.3 ASCE Standards:
ASCE 15 Standard Practice for the Direct Design of Buried Precast Reinforced Concrete Pipe Using Standard Installations
(SIDD)
3. Terminology
3.1 For definitions of terms relating to concrete pipe, see Terminology C822.
3.2 For terminology related to soil classifications, see Practice D2487 and Practice D2488.
3.3 For terminology and definitions of terms relating to structural design, see ASCE 15.
3.4 Fig. 1 illustrates the definitions and limits of the terms: foundation, subgrade, bedding, outer bedding, middle bedding, haunch,
lower side, backfill or overfill, invert, crown, springline, top of pipe, and bottom of pipe as used in this practice.
4. Significance and Use
4.1 This practice is useful as a reference by an owner and the owner’s engineer in preparing project specifications.
FIG. 1 Pipe/Installation Terminology
Available from American Society of Civil Engineers (ASCE), 1801 Alexander Bell Dr., Reston, VA 20191, http://www.asce.org.
C1479 − 16 (2021)
5. Notations
D = inside diameter of pipe, in.
i
D = outside diameter of pipe, in.
o
H = design height of earth above top of pipe, ft.
w = unit weight of soil, lb/ft .
6. Standard Installations
6.1 The precast concrete pipe/soil system shall be constructed to conform to the requirements of Figs. 2 and 3 and Tables 1 and
2 as designated on the plans.
7. Excavation
7.1 When rock or other unyielding foundation material is encountered, it shall be removed at least to the requirements shown in
Figs. 2 and 3 and Tables 1 and 2. Overexcavated areas shall be backfilled with approved materials and compacted to at least the
standard proctor density specified for the bedding.
7.2 Where surface water or groundwater conditions exist, the site and trench shall be dewatered.
8. Foundation
8.1 The foundation shall be moderately firm to hard in situ soil, stabilized soil, or compacted fill material.
8.2 When unsuitable or unstable material is encountered, the foundation shall be stabilized.
FIG. 2 Standard Embankment Installations
C1479 − 16 (2021)
NOTE 1—Clearance between pipe and trench wall shall be adequate to enable specified compaction but not less than D /6.
o
FIG. 3 Standard Trench Installations
8.3 Methods to prevent migration of soil fines shall be provided when groundwater or existing soil conditions are conducive to
particle migration. Gravelly soils, with little or no fines, could migrate under certain conditions, causing lack of support.
8.4 Pipe installed over an unyielding foundation shall be cushioned so as to prevent blasting shock when future blasting is
anticipated in the area.
9. Bedding
9.1 The bedding shall be constructed uniformly over the full length of the pipe barrel, as required for the designated standard
installation, to distribute the loadbearing reaction uniformly on the pipe barrel over its full length, and to maintain the required pipe
grade. See Fig. 4. If placed in layers, the thickness of the layers shall be as required to achieve the specified compaction and as
required by the project specifications.
9.2 The bedding layers for standard installation Types 1, 2, and 3 shall be placed to be as uniform as possible, but shall be loosely
placed uncompacted material under the middle third of the pipe prior to placement of the pipe.
9.3 The maximum aggregate size shall be 1 in. when the bedding thickness is less than 6 in. and 1 ⁄2-in. when the bedding
thickness is 6 in. or greater, except as noted in 9.4.
9.4 When in situ soils conforming to project specifications are used in constructing the outer bedding for Type 3 and 4 installations,
the maximum aggregate size shall not be greater than 3 in., or half the bedding thickness, whichever is less.
9.5 The use of aggregate sizes larger than 1 in. shall be limited to 20 % of the bedding material by weight.
9.6 Bell holes shall be excavated in the bedding or foundation, or both, when installing pipe with expanded bells so that the pipe
is supported by the barrel and not by the bells. See Fig. 4.
C1479 − 16 (2021)
TABLE 1 Standard Embankment Installation Soils and Minimum Compaction Requirements
NOTE 1—Compaction and soil symbols (that is, 95 % Category I) refer to a soil material category with a minimum standard proctor density. See Table
3 for equivalent modified proctor values and soil types.
NOTE 2—Type 1 installations require greater soil stiffness from the surrounding soils than the Type 2, 3, and 4 installations. Proper field verification
of soil properties and compaction levels must be performed to ensure compliance with the design requirements. See Appendix X2 for more information
and guidance.
NOTE 3—For Type 1 installation, crushed rock is not an appropriate material for bedding under the pipe. An uncompacted, non-crushed material must
be used under the middle third of the pipe outside diameter. While crushed rock meeting the requirements of this specification may self compact vertically,
it will not flow laterally to provide support for the haunches of the pipe. To achieve a 90 to 95 % compaction with crushed rock, work material under
the haunch and compact it to achieve the specified density. Otherwise, the specified installation is not achieved.
NOTE 4—Soil in the outer bedding, haunch, and lower side zones, except within D /3 from the pipe springline, shall be compacted to at least the same
o
compaction as the majority of soil in the overfill zone.
NOTE 5—Required bedding thickness is the thickness of the bedding prior to placement of the pipe.
NOTE 6—A subtrench is defined as a trench with its top below finished grade by more than 0.1 H or, for roadways, its top is at an elevation lower than
1 ft below the bottom of the pavement base material.
The minimum width of a subtrench shall be 1.33 D , or wider, if required for adequate space to attain the specified compaction in the haunch and
o
bedding zones.
For subtrenches, except within D /3 from the springline, any portion of the lower side zone in the subtrench wall shall be at least as firm as an equivalent
o
soil placed to the compaction requirements specified for the lower side zone and as firm as the majority of soil in the overfill zone, or it shall be removed
and replaced with soil compacted to the specified level.
NOTE 7—“Dumped” material without additional compactive effort will not provide the design haunch support required for Type 1 and 2 installations.
Installation Bedding Haunch and Lower
Type Thickness Outer Bedding Side
Type 1 D /24 minimum; not less than 3 in. If rock 95 % Category I 90 % Category I,
o
foundation, use D /12 minimum; not less than 6 95 % Category II
o
in.
Type 2 D /24 minimum; not less than 3 in. If rock 90 % Category I or 85 % Category I,
o
foundation, use D /12 minimum; not less than 6 95 % Category II 90 % Category II,
o
in. or 95 % Category III
Type 3 D /24 minimum; not less than 3 in. If rock 85 % Category I, 85 % Category I,
o
foundation, use D /12 minimum; not less than 6 90 % Category II, or 90 % Category II, or
o
in. 95 % Category III 95 % Category III
Type 4 No bedding required, except if rock foundation, No compaction required, No compaction required,
use D /12 minimum; not less than 6 in. except if Category III, except if Category III,
o
use 85 % Category III use 85 % Category III
9.7 Any outer bedding under the lower side areas shall be compacted to at least the same requirements as for the lower side areas.
10. Pipe Placement and Joining
10.1 Pipe shall be installed to the line and grade shown on the project plans and specifications. The joint shall be as specified in
the project specifications and shall be installed in accordance with the pipe manufacturer’s recommendations.
NOTE 1—(Advisory) Where practical, work should be started at the lowest end of the pipeline and the pipe laid with the bell end upgrade.
10.2 If required, the top of the pipe section being laid shall be positioned to the correct rotational orientation and then joined.
10.3 The bedding grade under the middle third of the pipe outside diameter shall be prepared before laying the pipe section.
Making adjustments in grade by exerting force on the barrel of the pipe with excavating equipment, by lifting and dropping the
pipe, or by lifting the pipe and packing bedding material under it shall be prohibited. If the installed pipe section is not on grade,
the pipe section shall be completely unjoined, the grade corrected, and the pipe then rejoined.
11. Haunch
11.1 The haunch shall be constructed using the specified soil type and the minimum compaction level required for the designated
standard installation. It shall be placed and compacted uniformly for the full length of the pipe barrel so as to distribute the
C1479 − 16 (2021)
TABLE 2 Standard Trench Installation Soils and Minimum Compaction Requirements
NOTE 1—Compaction and soil symbols (that is, 95 % Category I) refer to a soil material category with a minimum standard proctor density. See Table
3 for equivalent modified proctor values and soil types.
NOTE 2—Type 1 installations require greater soil stiffness from the surrounding soils than the Type 2, 3, and 4 installations. Proper field verification
of soil properties and compaction levels must be performed to ensure compliance with the design requirements. See Appendix X2 for more information
and guidance.
NOTE 3—For Type 1 installation, crushed rock is not an appropriate material for bedding under the pipe. An uncompacted, non-crushed material must
be used under the middle third of the pipe outside diameter. While crushed rock meeting the requirements of this specification may self compact vertically,
it will not flow laterally to provide support for the haunches of the pipe. To achieve a 90 to 95 % compaction with crushed rock, work material under
the haunch and compact it to achieve the specified density. Otherwise, the specified installation is not achieved.
NOTE 4—When the trench width specified must be exceeded, the owner shall be notified.
NOTE 5—The trench width shall be wider than shown (Fig. 3) if required for adequate space to attain the specified compaction in the haunch and
bedding zones.
NOTE 6—Embankment loading shall be used when trench walls consist of embankment unless a geotechnical analysis is made and the soil in the trench
walls is compacted to a higher level than the soil in the backfill zone.
NOTE 7—Required bedding thickness is the thickness of the bedding prior to placement of the pipe.
NOTE 8—“Dumped” material without additional compactive eff
...