ASTM D3839-14(2019)

Standard Guide for Underground Installation of “Fiberglass” (Glass-Fiber Reinforced Thermosetting-Resin) Pipe

SIGNIFICANCE AND USE
4.1 This practice is for use by designers and specifiers, manufacturers, installation contractors, regulatory agencies, owners, and inspection organizations involved in the construction of buried fiberglass pipelines. As with any practice, modifications may be required for specific job conditions, or for special local or regional conditions. Recommendations for inclusion of this practice in contract documents for a specific project are given in Appendix X1.
SCOPE
1.1 This practice establishes procedures for the burial of pressure and nonpressure “fiberglass” (glass-fiber-reinforced thermosetting-resin) pipe in many typically encountered soil conditions. Included are recommendations for trenching, placing pipe, joining pipe, placing and compacting backfill, and monitoring deflection levels. Guidance for installation of fiberglass pipe in subaqueous conditions is not included.  
1.2 Product standards for fiberglass pipe encompass a wide range of product variables. Diameters range from 1 in. to 13 ft (25 mm to 4000 mm) and pipe stiffnesses range from 9 to over 72 psi (60 to 500 kPa) with internal pressure ratings up to several thousand pound force per square inch. This standard does not purport to consider all of the possible combinations of pipe, soil types, and natural ground conditions that may occur. The recommendations in this practice may need to be modified or expanded to meet the needs of some installation conditions. In particular, fiberglass pipe with diameters of a few inches are generally so stiff that they are frequently installed in accordance with different guidelines. Consult with the pipe manufacturer for guidance on which practices are applicable to these particular pipes.  
1.3 The scope of this practice excludes product-performance criteria such as a minimum pipe stiffness, maximum service deflection, or long-term strength. Such parameters may be contained in product standards or design specifications, or both, for fiberglass pipe. It is incumbent upon the specified product manufacturer or project engineer to verify and ensure that the pipe specified for an intended application, when installed in accordance with procedures outlined in this practice, will provide a long-term, satisfactory performance in accordance with criteria established for that application.  
Note 1: There is no known ISO equivalent to this standard.
Note 2: A discussion of the importance of deflection and a presentation of a simplified method to approximate field deflections are given in AWWA Manual of Practice M45 Fiberglass Pipe Design.  
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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: Published
• Publication Date: 31-Jul-2019
• ICS: 23.040.20 - Plastics pipes
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.23 - Reinforced Thermosetting Resin Piping Systems and Chemical Equipment

Relations

• Replaces: ASTM D3839-14 - Standard Guide for Underground Installation of “Fiberglass” (Glass-Fiber Reinforced Thermosetting-Resin) Pipe
• Effective Date: 01-Aug-2019
• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM D4959-24 - Standard Test Method for Determination of Water Content of Soil By Direct Heating
• Effective Date: 01-Feb-2024
• Refers: ASTM D883-23 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2023
• Refers: ASTM D7382-20 - Standard Test Methods for Determination of Maximum Dry Unit Weight of Granular Soils Using a Vibrating Hammer
• Effective Date: 01-Jul-2020
• Refers: ASTM F412-20 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Apr-2020
• Refers: ASTM D883-20 - Standard Terminology Relating to Plastics
• Effective Date: 01-Jan-2020
• Refers: ASTM D883-19c - Standard Terminology Relating to Plastics
• Effective Date: 01-Aug-2019
• Refers: ASTM D8-19 - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 01-Aug-2019
• Refers: ASTM D883-19a - Standard Terminology Relating to Plastics
• Effective Date: 15-Apr-2019
• Refers: ASTM D2216-19 - Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
• Effective Date: 01-Mar-2019
• Refers: ASTM D883-19 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2019
• Refers: ASTM F412-19 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Jan-2019
• Refers: ASTM D8-18c - Standard Terminology Relating to Materials for Roads and Pavements
• Effective Date: 15-Dec-2018
• Refers: ASTM D883-18a - Standard Terminology Relating to Plastics
• Effective Date: 01-Dec-2018

Overview

ASTM D3839-14(2019): Standard Guide for Underground Installation of “Fiberglass” (Glass-Fiber Reinforced Thermosetting-Resin) Pipe provides comprehensive guidance for the safe, reliable, and effective underground installation of fiberglass-reinforced thermosetting-resin (FRP) pipes. Developed under the jurisdiction of ASTM Committee D20 on Plastics and specifically by Subcommittee D20.23 on Reinforced Plastic Piping Systems and Chemical Equipment, this standard is indispensable for engineers, designers, specifiers, manufacturers, contractors, owners, and regulatory agencies involved in the construction and inspection of buried fiberglass pipe systems.

This ASTM guide outlines best practices for key activities including trench excavation, pipe placement, joining, backfilling, and monitoring of pipe deflection for both pressure and nonpressure fiberglass pipelines across a wide range of soil conditions. It emphasizes the necessity of adapting its recommendations to local conditions and project-specific challenges to ensure long-term pipe performance and structural integrity.

Key Topics

• Scope of Application: Covers procedures for burying glass-fiber-reinforced thermosetting-resin pipes of various diameters (1 inch to 13 feet / 25 mm to 4000 mm) and a wide range of stiffness and pressure ratings.
• Trenching and Excavation: Offers recommendations on suitable trench widths, stabilization of trench walls, dealing with unstable soils, and moisture management.
• Pipe Placement and Support: Provides guidelines for installing bedding and haunching, as well as handling, aligning, and supporting the pipe throughout installation.
• Joining Methods: Recommends best practices for assembly, jointing, and testing of different types of fiberglass pipe joints, including elastomeric seals and adhesive-bonded options.
• Compaction and Backfilling: Specifies appropriate backfill materials and compaction techniques by soil classification, ensuring proper pipe support and minimizing post-installation deflection.
• Monitoring Deflection: Highlights the importance of measuring and managing post-installation deflection for long-term system performance.
• Soil and Aggregate Selection: Classifies soils and aggregates (e.g., Class I, II, III, IV, and V) and provides installation recommendations for each class to maximize pipe support.
• Adaptability: Stresses the need to consult manufacturers for guidance on specific products or non-standard installation situations, especially with small-diameter or particularly stiff pipes.
• Safety and Compliance: Advises on establishing appropriate safety, health, and environmental practices, as well as considering all regulatory requirements.

Applications

• Municipal Water and Wastewater Systems: Ideal for underground installation of fiberglass pipelines in urban infrastructure, with a focus on durability and minimal maintenance.
• Industrial Piping: Suitable for industries requiring corrosion-resistant underground pipework for chemical transport, process water, or wastewater.
• Irrigation and Drainage: Supports installation of large-diameter FRP pipes for agricultural drainage or irrigation systems.
• Infrastructure Projects: Applicable to buried pipe sections in transportation tunnels, stormwater systems, and other public works.
• New Construction and Rehabilitation: Provides guidance for both new pipeline installations and upgrades to existing underground fiberglass pipelines.

Related Standards

• ASTM D2487: Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)
• ASTM D698: Proctor Compaction Test for Laboratory Compaction Characteristics of Soil
• AASHTO LRFD Bridge Design Specifications: Guidelines referenced for soil classifications and structural applications in transportation projects
• AWWA Manual of Practice M45: Reference guide for fiberglass pipe design, especially regarding deflection calculations
• ASTM F1668: Guide for Construction Procedures for Buried Plastic Pipe

Note: There is currently no known ISO equivalent for ASTM D3839-14(2019).

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ASTM D3839-14(2019) serves as an industry benchmark for the underground installation of fiberglass-reinforced thermosetting-resin pipes, promoting best practices for pipeline longevity, performance, and safety. Stakeholders are encouraged to integrate this standard into project specifications and adapt its recommendations to local conditions for optimized results. For additional guidance, consult referenced standards and collaborate with pipe manufacturers for application-specific advice.

Standards Content (Sample)

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: D3839 − 14 (Reapproved 2019)
Standard Guide for
Underground Installation of “Fiberglass” (Glass-Fiber
Reinforced Thermosetting-Resin) Pipe
This standard is issued under the fixed designation D3839; 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.
AWWA Manual of Practice M45 Fiberglass Pipe Design.
1. Scope*
1.4 Thevaluesstatedininch-poundunitsaretoberegarded
1.1 This practice establishes procedures for the burial of
as standard. The values given in parentheses are mathematical
pressure and nonpressure “fiberglass” (glass-fiber-reinforced
conversions to SI units that are provided for information only
thermosetting-resin) pipe in many typically encountered soil
and are not considered standard.
conditions. Included are recommendations for trenching, plac-
ing pipe, joining pipe, placing and compacting backfill, and
1.5 This standard does not purport to address all of the
monitoring deflection levels. Guidance for installation of
safety concerns, if any, associated with its use. It is the
fiberglass pipe in subaqueous conditions is not included.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.2 Product standards for fiberglass pipe encompass a wide
mine the applicability of regulatory limitations prior to use.
range of product variables. Diameters range from 1 in. to 13 ft
1.6 This international standard was developed in accor-
(25 mm to 4000 mm) and pipe stiffnesses range from 9 to over
dance with internationally recognized principles on standard-
72 psi (60 to 500 kPa) with internal pressure ratings up to
ization established in the Decision on Principles for the
several thousand pound force per square inch. This standard
Development of International Standards, Guides and Recom-
doesnotpurporttoconsiderallofthepossiblecombinationsof
mendations issued by the World Trade Organization Technical
pipe, soil types, and natural ground conditions that may occur.
Barriers to Trade (TBT) Committee.
Therecommendationsinthispracticemayneedtobemodified
or expanded to meet the needs of some installation conditions.
2. Referenced Documents
Inparticular,fiberglasspipewithdiametersofafewinchesare
2.1 ASTM Standards:
generally so stiff that they are frequently installed in accor-
dance with different guidelines. Consult with the pipe manu- D8Terminology Relating to Materials for Roads and Pave-
facturerforguidanceonwhichpracticesareapplicabletothese ments
particular pipes. D653Terminology Relating to Soil, Rock, and Contained
Fluids
1.3 The scope of this practice excludes product-
D698Test Methods for Laboratory Compaction Character-
performance criteria such as a minimum pipe stiffness, maxi-
istics of Soil Using Standard Effort (12,400 ft-lbf/ft (600
mum service deflection, or long-term strength. Such param-
kN-m/m ))
eters may be contained in product standards or design
D883Terminology Relating to Plastics
specifications,orboth,forfiberglasspipe.Itisincumbentupon
D1556Test Method for Density and Unit Weight of Soil in
thespecifiedproductmanufacturerorprojectengineertoverify
Place by Sand-Cone Method
and ensure that the pipe specified for an intended application,
D2167Test Method for Density and Unit Weight of Soil in
when installed in accordance with procedures outlined in this
Place by the Rubber Balloon Method
practice, will provide a long-term, satisfactory performance in
D2216TestMethodsforLaboratoryDeterminationofWater
accordance with criteria established for that application.
(Moisture) Content of Soil and Rock by Mass
NOTE 1—There is no known ISO equivalent to this standard.
D2487Practice for Classification of Soils for Engineering
NOTE 2—A discussion of the importance of deflection and a presenta-
Purposes (Unified Soil Classification System)
tion of a simplified method to approximate field deflections are given in
D2488Practice for Description and Identification of Soils
(Visual-Manual Procedures)
ThispracticeisunderthejurisdictionofASTMCommitteeD20onPlasticsand
is the direct responsibility of Subcommittee D20.23 on Reinforced Plastic Piping
Systems and Chemical Equipment. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Aug. 1, 2019. Published August 2019. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1979. Last previous edition approved in 2014 as D3839–14. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D3839-14R19. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3839 − 14 (2019)
D4253Test Methods for Maximum Index Density and Unit Crushedrockhashighcompactibilitybecauseadenseandstiff
Weight of Soils Using a Vibratory Table state may be achieved with little compactive energy.
D4254Test Methods for Minimum Index Density and Unit
3.2.3 deflection—any change in the inside diameter of the
Weight of Soils and Calculation of Relative Density
pipe resulting from installation or imposed loads, or both;
D4318Test Methods for Liquid Limit, Plastic Limit, and
deflection may be either vertical or horizontal and is usually
Plasticity Index of Soils
reported as a percentage of the nominal inside pipe diameter.
D4564Test Method for Density and Unit Weight of Soil in
3.2.4 engineer—the engineer in responsible charge of the
Place by the Sleeve Method (Withdrawn 2013)
work or his duly recognized or authorized representative.
D4643Test Method for Determination of Water Content of
Soil and Rock by Microwave Oven Heating
3.2.5 fiberglass pipe—a tubular product containing glass-
D4914Test Methods for Density of Soil and Rock in Place
fiber reinforcements embedded in or surrounded by cured
by the Sand Replacement Method in a Test Pit
thermosetting resin; the composite structure may contain
D4944TestMethodforFieldDeterminationofWater(Mois-
aggregate, granular, or platelet fillers, thixotropic agents,
ture)ContentofSoilbytheCalciumCarbideGasPressure
pigments, or dyes; thermoplastic or thermosetting liners or
Tester
coatings may be included.
D4959Test Method for Determination of Water Content of
3.2.6 final backfill—backfill material placed from the top of
Soil By Direct Heating
the initial backfill to the ground surface (see Fig. 1.)
D5030Test Methods for Density of Soil and Rock in Place
3.2.7 fines—soil particles that pass a No. 200 (0.076 mm)
by the Water Replacement Method in a Test Pit
sieve.
D5080Test Method for Rapid Determination of Percent
Compaction
3.2.8 foundation—in situ soil or, in the case of unsuitable
D5821Test Method for Determining the Percentage of
ground conditions compacted backfill material, in the bottom
Fractured Particles in Coarse Aggregate
ofthetrenchthesupportsthebeddingandthepipe(seeFig.1).
D6938TestMethodsforIn-PlaceDensityandWaterContent
3.2.9 geotextile—any permeable textile material used with
of Soil and Soil-Aggregate by Nuclear Methods (Shallow
foundation, soil, earth, rock, or any other geotechnical engi-
Depth)
neering related material, as an integral part of a man-made
D7382Test Methods for Determination of Maximum Dry
product, structure, or system.
Unit Weight and Water Content Range for Effective
3.2.10 haunching—backfill material placed on top of the
Compaction of Granular Soils Using aVibrating Hammer
bedding and under the springline of the pipe; the term
(Withdrawn 2017)
haunching only pertains to soil directly beneath the pipe (see
F412Terminology Relating to Plastic Piping Systems
Fig. 1).
F1668Guide for Construction Procedures for Buried Plastic
Pipe
3.2.11 initial backfill—backfill material placed at the sides
2.2 Other Standards:
of the pipe and up to 6 to 12 in. (150 to 300 mm) over the top
AASHTOLRFDBridgeDesignSpecifications,2ndEdition,
of the pipe, including the haunching.
American Association of State Highway and Transporta-
4 3.2.12 manufactured aggregates—aggregates that are prod-
tion Officials
ucts or by-products of a manufacturing process, or natural
AASHTO M145Classification of Soils and Soil Aggregate
4 aggregates that are reduced to their final form by a manufac-
Mixtures
turing process such as crushing.
AWWAManual of Practice M45 Fiberglass Pipe Design
Manual 3.2.13 modulus of soil reaction (E')—an empirical value
usedintheIowadeflectionformulathatdefines thestiffnessof
3. Terminology
the soil embedment around a buried pipe.
3.1 Definitions:
3.2.14 native (in situ) soil—natural soil in which a trench is
3.1.1 General—Unless otherwise indicated, definitions are
excavated for pipe installation or on which a pipe and
in accordance with Terminologies D8, D653, D883, and F412.
embankment are placed.
3.2 Definitions of Terms Specific to This Standard:
3.2.15 open-graded aggregate—an aggregate with a
3.2.1 bedding—backfill material placed in the bottom of the
particle-size distribution such that when compacted, the result-
trench or on the foundation to provide a uniform material on
ing voids between the aggregate particles are relatively large.
which to lay the pipe.
3.2.16 optimum moisture content—the moisture content of
3.2.2 compactibility—a measure of the ease with which a
soil at which its maximum density is obtained. (See Test
soil may be compacted to a high density and high stiffness.
Method D698.)
3.2.17 percent compaction—the ratio, expressed as a
The last approved version of this historical standard is referenced on
percentage, of: (1) dry unit weight of a soil, to (2) maximum
www.astm.org.
Available from American Association of State Highway and Transportation unit weight obtained in a laboratory compaction test.
Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001.
3.2.18 pipe zone embedment—all backfill around the pipe;
Available fromAmericanWaterWorksAssociation (AWWA), 6666W. Quincy
Ave., Denver, CO 80235, http://www.awwa.org. this includes the bedding, haunching, and initial backfill.
D3839 − 14 (2019)
*See 7.7, Minimum Cover.
FIG. 1 Trench Cross-Section Terminology
3.2.19 processed aggregates—aggregates which are the top of the bedding to a depth of at least 0.6 times the
screened or washed or mixed or blended to produce a specific diameter and the second material extends to the top of the
particle-size distribution. initial backfill.
3.2.20 secant constrained soil modulus (M )—a value for
3.2.23 standard proctor density (SPD)—the maximum dry
s
soil stiffness determined as the secant slope of the stress-strain
unit weight of soil compacted at optimum moisture content, as
curve of a one-dimensional compression test; M can be used
obtained by laboratory test in accordance with Test Methods
s
in place of E' in the Iowa deflection formula.
D698.
3.2.21 soil stiffness—a property of soil, generally repre-
4. Significance and Use
sented numerically by a modulus of deformation that indicates
the relative amount of deformation that will occur under a
4.1 This practice is for use by designers and specifiers,
given load.
manufacturers, installation contractors, regulatory agencies,
3.2.22 split installation—an installation in which the initial owners, and inspection organizations involved in the construc-
backfill consists of two different materials or one material tion of buried fiberglass pipelines. As with any practice,
placedattwodifferentdensities;thefirstmaterialextendsfrom modifications may be required for specific job conditions, or
D3839 − 14 (2019)
for special local or regional conditions. Recommendations for 5.2.1 Soil Class I—Class I materials provide maximum
inclusion of this practice in contract documents for a specific stability and pipe support for a given percent compaction due
project are given in Appendix X1.
tothelowcontentofsandandfines.Withminimumeffortthese
materialscanbeinstalledatrelativelyhigh-soilstiffnessesover
5. Materials
a wide range of moisture contents. In addition, the high
permeability of Class I materials may aid in the control of
5.1 Classification—Soil types used or encountered in bury-
water,andthesematerialsareoftendesirableforembedmentin
ing pipes include those natural soils classified in Practice
rock cuts where water is frequently encountered. However,
D2487 and manufactured and processed aggregates. The soil
whenground-waterflowisanticipated,considerationshouldbe
materials are grouped into soil classes in Table 1 based on the
given to the potential for migration of fines from adjacent
typical soil stiffness when compacted. Class I indicates a soil
materials into the open-graded Class I materials. (See 5.6.)
that generally provides the highest soil stiffness at any given
percentcompaction,andprovidesagivensoilstiffnesswiththe
5.2.2 Soil Class II—Class II materials, when compacted,
leastcompactiveeffort.Eachhigher-numbersoilclassprovides
provide a relatively high level of pipe support; however,
successively less soil stiffness at a given percent compaction
open-graded groups may allow migration and the sizes should
and requires greater compactive effort to provide a given level
be checked for compatibility with adjacent material; see 5.6.
of soil stiffness.
5.2.3 Soil Class III—ClassIIImaterialsprovidelesssupport
for a given percent compaction than Class I or Class II
NOTE 3—See Practices D2487 and D2488 for laboratory and field
visual-manual procedures for identification of soils.
materials. Higher levels of compactive effort are required and
NOTE 4—Processed materials produced for highway construction,
moisture content must be near optimum to minimize compac-
including coarse aggregate, base, subbase, and surface coarse materials,
tive effort and achieve the required percent compaction. These
whenusedforfoundation,embedment,andbackfill,shouldbecategorized
materialsprovidereasonablelevelsofpipesupportonceproper
in accordance with this section and Practice D2487 in accordance with
particle size and gradation. percent compaction is achieved.
5.2 Installation and Use—Table 2 provides recommenda- 5.2.4 Soil Class IV—Class IV materials require a geotech-
nical evaluation prior to use. Moisture content must be near
tions on installation and use based on soil-stiffness class and
location in the trench. Soil Classes I to IV should be used as optimum to minimize compactive effort and achieve the
recommendedinTable2.SoilClassV,includingclaysandsilts required percent compaction. Properly placed and compacted,
with liquid limits greater than 50%, organic soils, and frozen Class IV materials can provide reasonable levels of pipe
soils, shall be excluded from the pipe-zone embedment. support; however, these materials may not be suitable under
A,B,C,D
TABLE 1 Soil Classes
American Association of State Highway and
A,E
Soil Group Soil Class
B
Transportation Officials (AASHTO) Soil Groups
C
Crushed rock : Class I
sieve and maximum 5 % passing a #200 sieve
Clean, coarse grained soils: Class II A1, A3
SW, SP, GW, GP or any soil beginning with one
of these symbols with 12 % or less passing a
D,F
#200 sieve
Coarse grained soils with fines: Class III A-2–4, A-2–5, A-2–6, or A-4 or A-6 soils with
GM, GC, SM, SC, or any soil beginning with one more than 30% retained on a No. 200 sieve
of these symbols, containing more than 12 %
passing a #200 sieve;
Sandy or gravelly fine-grained soils:
CL, ML, or any soil beginning with
one of these symbols, with
$30 % retained on a #200 sieve
Fine-grained soils: Class IV A-2-7, or A-4, or A-6 soils with 30% or less
CL, ML, or any soil beginning with one of these retained on a No. 200 sieve
symbols, with <30 % retained on a #200 sieve
MH, CH, OL, OH, PT Class V A5, A7
Not for use as
embedment
A
ASTM D2487 Standard Classification of Soils for Engineering Purposes (Unified Soil Classification System)
B
AASHTO M145, Classification of Soils and Soil Aggregate Mixtures.
C
Crushed rock is defined as angular and subangular in accordance with ASTM D2488.
D
Uniformfinesands(SP)withmorethan50 %passingaNo.100sieve(0.0006in.,0.15mm)areverysensitivetomoistureandshouldnotbeusedasbackfillforfiberglass
pipe unless specifically allowed in the contract documents. If use of these materials is allowed, compaction and handling procedures should follow the guidelines for Class
III materials.
E
Limitsmaybeimposedonthesoilgrouptomeetprojectorlocalrequirementsifthespecifiedsoilremainswithinthegroup.Forexample,someprojectapplicationsrequire
a Class I material with minimal fines to address specific structural or hydraulic conditions and the specification may read: “Use Class I soil with a maximum of 5% passing
the #200 sieve.”
F
Materials such as broken coral, shells, and recycled concrete, with#12 % passing a No. 200 sieve, are considered to be Class II materials. These materials should only
be used when evaluated and approved by the Engineer.
D3839 − 14 (2019)
TABLE 2 Recommendations for Installation and Use of Soils and Aggregates for Foundation and Pipe-Zone Embedment
A D
Soil Class Class I Class II Class III Class IV
General Recommendations Acceptable and common where Where hydraulic gradient exists Do not use where water Difficult to achieve high-soil
and Restrictions no migration is probable or check gradation to minimize conditions in trench prevent stiffness. Do not use where
when combined with a migration. Clean groups are proper placement and water conditions in trench
geotextile filter media. Suitable suitable for use as a drainage compaction. Not recommended prevent proper placement and
for use as a drainage blanket blanket and underdrain (see for use with pipes with stiffness compaction. Not recommended
and under drain where adjacent Table 1). Uniform fine sands of 9 psi or less for use with pipes with stiffness
material is suitably graded or (SP) with more than 50 % of 9 psi or less
when used with a geotextile passing a #100 sieve (0.006 in.,
filter fabric (see 5.6). 0.15 mm) behave like silts and
should be treated as Class III
soils.
Foundation Suitable as foundation and for Suitable as foundation and for Suitable for replacing over- Suitable for replacing over-
replacing over-excavated and replacing over-excavated and excavated trench bottom as excavated trench bottom for
unstable trench bottom as unstable trench bottom as restricted above. Install and depths up to 12 in. as restricted
restricted above. restricted above. Install and compact in 6 in. (150 mm) above. Use only where uniform
compact in 12 in. (300 mm) maximum layers longitudinal support of the pipe
maximum layers can be maintained, as
approved by the engineer.
Install and compact in 6-in (150
mm) maximum layers.
Pipe Zone Embedment Suitable as restricted above. Suitable as restricted above. Suitable as restricted above. Suitable as restricted above.
Work material under pipe to Work material under pipe to Difficult to place and compact in Difficult to place and compact in
provide uniform haunch provide uniform haunch the haunch zone. the haunch zone.
support. support.
Embedment Compaction:
C
Min Recommended Percent 85 % (SW and SP soils) 90 % 95 %
B E
Compaction, SPD For GW and GP soils, see .
Relative Compactive Effort low moderate high very high
Required to Achieve
Minimum Percent Compaction
Compaction Methods vibration or impact vibration or impact impact impact
Required Moisture Control none none maintain near optimum to maintain near optimum to
minimize compactive effort minimize compactive effort
A
Class V materials are unsuitable as embedment. They may be used as final backfill as permitted by the engineer.
B
SPD is standard Proctor density as determined by Test Method D698.
C
Suitable compaction typically achieved by dumped placement (that is, uncompacted but worked into haunch zone to ensure complete placement).
D
Class I materials have higher stiffness than Class II materials, but data on specific soil stiffness values are not available at the current time. Until such data are available
thesoilstiffnessofplaced,uncompactedClassImaterialscanbetakenequivalenttoClassIImaterialscompactedto95 %ofmaximumstandardProctordensity(SPD95),
and the soil stiffness of compacted Class I materials can be taken equivalent to Class II materials compacted to 100 % of maximum standard Proctor density (SPD100).
Even if placed uncompacted (that is, dumped), Class I materials should always be worked into the haunch zone to assure complete placement.
E
Place and compact GW and GP soils with at least two passes of compaction equipment.
high fills, surface-applied wheel loads, or under high-energy- stiffness pipe is embedded in backfill materials that require
level vibratory compactors and tampers. Do not use where large compactive efforts. This occurs because of the local
water conditions in the trench may prevent proper placement distortionsofthepipeshapethatresultascompactiveenergyis
and compaction. applied to the backfill. Because of this it is recommended that
pipe with stiffness of 9 psi or less should only be embedded in
NOTE 5—The term “high energy level vibratory compactors and
soil types Class I or Class II.
tampers” refers to compaction equipment that might deflect or distort the
pipe more than permitted by the specifications or the manufacturer.
5.5 Maximum Particle Size—Maximum particle size for
5.2.5 Soil Class V—Class V materials should be excluded pipe-zone embedment is limited based on pipe diameter as
from pipe-zone embedment. listed in Table 3. For final backfill, the maximum particle size
allowed should not exceed 75% of the lift thickness. When
5.3 Moisture Content of Embedment Materials—The mois-
final backfill contains cobbles, boulders, etc., the initial bed-
ture content of embedment materials must be controlled to
ding should be extended above the top of the pipe at least 12
permit placement and compaction to required levels. For soils
in. (300 mm). Backfill containing particles larger than 8 in.
withlowpermeability(thatis,ClassIIIandClassIVandsome
borderline Class II soils), moisture content is normally con-
trolled to 63% of optimum (see Test Method D698). The TABLE 3 Maximum Particle Size for Pipe Embedment
practicalityofobtainingandmaintainingtherequiredlimitson
Maximum Particle
Nominal Diameter (D)) Range,
i
Size,
moisture content is an important criterion for selecting
in. (mm)
in., (mm)
materials,sincefailuretoachieverequiredpercentcompaction,
D # 18 (D # 450) 0.50, (13)
i i
especiallyinthepipezoneembedment,mayresultinexcessive
18< D # 24 (450< D # 600) 0.75 (19)
i i
deflection.
24< D # 36 (600< D # 900) 1.00 (25)
i i
36< D # 48 (900< D # 1200) 1.25 (32)
i i
5.4 Compatibility of pipe and backfill—Experience has
48< D (1200< D) 1.50 (38)
i i
shownthatpipedeflectionsandstrainlevelsincreasewhenlow
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(200 mm) shall not be dropped on the backfill or rolled down and/or stiffness (soil cement, cement stabilized backfill) or to
a sloping trench wall from a height greater than 6 ft (1.8 m) improve flowability (flowable fill, controlled low strength
until the depth of fill over the top of the pipe is greater than 24 material) have been shown to be effective backfill materials in
in. (600 mm). terms of ease of placement and quality of support to pipe.
While not specifically addressed by this standard, use of these
NOTE 6—The limits of 200 mm (8 in.) particles and a drop height of 6
ft (1.8 m) are somewhat arbitrary, but serve to establish the principle that
materials is beneficial under many circumstances.
dropping boulders onto the backfill can damage the pipe even though
some backfill has already been placed on the pipe.
6. Trench Excavation
5.6 Migration—When open-graded material is placed adja-
6.1 Excavation—Excavate trenches to ensure that sides will
cent to a finer material, fines may migrate into the coarser
be stable under all working conditions. Slope trench walls or
material under the action of hydraulic gradient from ground-
provide supports in conformance with all local and national
water flow. Significant hydraulic gradients may arise in the
standards for safety. Place excavated material away from the
pipeline trench during construction, when water levels are
edge of the trench. Open only enough trench that can be safely
beingcontrolledbyvariouspumpingorwell-pointingmethods,
maintainedbyavailableequipment.Placeandcompactbackfill
or after construction, when permeable underdrain or embed-
in trenches as soon as practicable, preferably no later than the
ment materials act as a “french” drain under high groundwater
end of each working day.
levels. Field experience shows that migration can result in
6.2 Water Control—It is always good practice to remove
significant loss of pipe support and increasing deflections that
water from a trench before laying and backfilling pipe. While
may eventually exceed design limits. The gradation and
circumstancesoccasionallyrequirepipeinstallationinstanding
relative size of the embedment and adjacent materials must be
or running water conditions, such practice is outside the scope
compatible in order to minimize migration. In general, where
of this practice.At all times prevent run-off and surface water
significant groundwater is anticipated, avoid placing coarse,
from entering the trench.
open-graded materials, such as Class I, above, below, or
6.2.1 Groundwater—When groundwater is present in the
adjacent to finer materials, unless methods are employed to
workarea,dewatertomaintainstabilityofinsituandimported
impedemigrationsuchastheuseofanappropriatesoilfilteror
materials. Maintain the water level below pipe bedding to
ageotextilefilterfabricalongtheboundaryoftheincompatible
provide a stable trench bottom. Use, as appropriate, sump
materials.
pumps,wellpoints,deepwells,geotextiles,perforatedunderd-
5.6.1 The following filter gradation criteria may be used to
rains or stone blankets of sufficient thickness to remove and
restrict migration of fines into the voids of coarser material
control water in the trench. When excavating while lowering
under a hydraulic gradient:
thegroundwaterlevel,ensurethatthegroundwaterisbelowthe
D /d ,5 (1) bottom of cut at all times to prevent washout from behind
15 85
sheeting or sloughing of exposed trench walls. Maintain
where:
control of water in the trench before, during, and after pipe
D = sieve opening size passing 15% by weight of the
installation, and until embedment is installed and sufficient
coarser material, and
backfill has been placed to prevent flotation of the pipe. To
d = sieveopeningsizepassing85%byweightofthefiner
preclude loss of soil support, employ dewatering methods that
material.
minimize removal of fines and the creation of voids in in situ
D /d ,25 (2)
materials.
50 50
6.2.2 Running Water—Control running water emanating
where:
fromsurfacedrainageorgroundwatertoprecludeundermining
D = sieve opening size passing 50% by weight of the
ofthetrenchbottomorwalls,thefoundation,orotherzonesof
coarser material, and
embedment. Provide dams, cutoffs, or other barriers periodi-
d = sieveopeningsizepassing50%byweightofthefiner
callyalongtheinstallationtoprecludetransportofwateralong
material. This criterion need not apply if the coarser
the trench bottom. Backfill all trenches as soon as practical
material is well-graded (see Classification D2487).
after the pipe is installed to prevent disturbance of pipe and
embedment.
5.6.2 If the finer material is a medium to highly plastic clay
6.2.3 Materials for Water Control—Use suitably graded
withoutsandparticles(CLorCH),thenthefollowingcriterion
materialsinthefoundationasdrainageblanketsfortransportof
may be used instead of 5.6.1:
runningwatertosumppitsorotherdrains.Useproperlygraded
D ,0.02 in. ~0.5 mm! (3)
materials or perforated underdrains, or both, to enhance trans-
where: port of running water. Select the gradation of the drainage
materials to minimize migration of fines from surrounding
D = sieve-opening size passing 15% by weight of the
materials. (See 5.6.)
coarser material.
NOTE 7—Materials selected for use based on filter-gradation criteria
6.3 Minimum Trench Width—Where trench walls are stable
such as in 6.5 should be handled and placed in a manner that will
or supported, provide a width sufficient, but no greater than
minimize segregation.
necessary,toensureworkingroomtoproperlyandsafelyplace
5.7 Cementitious Backfill Materials—Backfill materials and compact haunching and other embedment materials. The
supplemented with cement to improve long-term strength spacebetweenthepipeandtrenchwallmustbe6in.(150mm)
D3839 − 14 (2019)
wider than the compaction equipment used in this region. For 6.4.3 Removal of Trench-Wall Support—If the engineer
a single pipe in a trench, the minimum width shall be not less permits the removal of sheeting or other trench-wall supports
than the greater of either the pipe outside diameter plus 16 in. that extend below the top of the pipe, ensure that neither pipe,
(400 mm) or the pipe outside diameter times 1.25, plus 12 in. foundation, nor embedment materials is disturbed by support
(300 mm). For multiple pipes in the same trench, interior removal.Fillvoidsleftonremovalofsupportsandcompactall
spaces between pipes must be at least the average of the radii material as required. Pulling the trench wall support in stages
of the two adjacent pipe for depths greater than 12 ft (3.5 m), as backfilling progresses is advised.
and ⁄3 of the average of the radii of the two adjacent pipe for
6.5 Trench-Bottom—Excavate trenches to a minimum depth
depths less than 12 ft (3.5 m); the distance from the outside
of 4 in. (100 mm) below the pipe. See 7.2 for guidance on
pipe to the trench wall must not be less than if that pipe were
installing foundation and bedding.
installedasasinglepipeinatrench.Ifmechanicalcompaction
6.5.1 When ledge, rock, hardpan or other unyielding
equipment is used, the minimum space between pipe and
material, cobbles, rubble or debris, boulders, or stones larger
trench wall, or between adjacent pipe shall not be less than the
than 1.5 in. (38 mm) are encountered in the trench bottom,
widthofthewidestpieceofequipmentplus6in.(150mm).In
excavate a minimum depth of 6
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