ASTM D8169/D8169M-18

Standard Test Methods for Deep Foundations Under Bi-Directional Static Axial Compressive Load

SIGNIFICANCE AND USE
4.1 The bi-directional axial compressive load test provides separate, direct measurements of the pile side shear mobilized above an embedded jack assembly and the pile end bearing plus any side shear mobilized below the jack assembly. The maximum mobilized pile resistance equals two times the maximum load applied by the jack assembly. Test results may also provide information used to assess the distribution of side shear resistance along the pile, the amount of end bearing mobilized at the pile bottom, and the long-term load-displacement behavior.  
4.2 The specified maximum test load should be consistent with the engineer’s desired test outcome. For permanent (working) piles, the engineer may require that the magnitude of applied test load be limited in order to measure the pile movement at a predetermined proof load as part of a quality control or quality assurance program. Tests that attempt to fully mobilize the axial compressive resistance of the test pile may allow the engineer to improve the efficiency of the pile design by reducing the piling length, quantity, or size.  
4.3 The engineer and other interested parties may analyze the results of a bi-directional axial compressive load test to estimate the load versus movement behavior and the pile capacity that would be measured during axial static compressive or tensile loading applied at the pile top (see Notes 1-3). Factors that may affect the pile response to axial static loading during a static test include, but are not limited to the:  
(1) pile installation equipment and procedures,
(2) elapsed time since initial installation,
(3) pile material properties and dimensions,
(4) type, density, strength, stratification, and groundwater conditions both adjacent to and beneath the pile,
(5) test procedure,
(6) prior load cycles.
Note 1: To estimate the load displacement curve for the pile as if it were loaded in compression at the top (as in Test Methods D1143/D1143M), the engineer may use strain...
SCOPE
1.1 The test methods described in this standard measure the axial displacement of a single, deep foundation element when loaded in bi-directional static axial compression using an embedded bi-directional jack assembly. These methods apply to all deep foundations, referred to herein as “piles,” which function in a manner similar to driven piles, cast in place piles, or barrettes, regardless of their method of installation. The test results may not represent the long-term performance of a deep foundation.  
1.2 This standard provides minimum requirements for testing deep foundations under bi-directional static axial compressive load. Plans, specifications, and/or provisions prepared by a qualified engineer may provide additional requirements and procedures as needed to satisfy the objectives of a particular test program. The engineer in charge of the foundation design, referred to herein as the engineer, shall approve any deviations, deletions, or additions to the requirements of this standard.  
1.3 This standard provides the following test procedures:    
Procedure A  
Quick Test  
9.2.1  
Procedure B  
Extended Test (optional)  
9.2.2  
1.4 Apparatus and procedures herein designated “optional” may produce different test results and may be used only when approved by the engineer. The word “shall” indicates a mandatory provision, and the word “should” indicates a recommended or advisory provision. Imperative sentences indicate mandatory provisions.  
1.5 The engineer may use the results obtained from the test procedures in this standard to predict the actual performance and adequacy of piles used in the constructed foundation. See Appendix X1 for comments regarding some of the factors influencing the interpretation of test results.  
1.6 A qualified engineer (specialty engineer, not to be confused with the foundation engineer as defined above) shall design and approve the load test configuration and test proc...

General Information

• Status: Published
• Publication Date: 31-Dec-2017
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.11 - Deep Foundations

Relations

• Refers: ASTM D3740-23 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Nov-2023
• Refers: ASTM D3740-19 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Oct-2019
• Refers: ASTM D6760-16 - Standard Test Method for Integrity Testing of Concrete Deep Foundations by Ultrasonic Crosshole Testing
• Effective Date: 01-Dec-2016
• Refers: ASTM D653-14 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Aug-2014
• Refers: ASTM D1143/D1143M-07(2013) - Standard Test Methods for Deep Foundations Under Static Axial Compressive Load
• Effective Date: 15-Jun-2013
• Refers: ASTM D3740-12a - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-May-2012
• Refers: ASTM D3740-12 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Mar-2012
• Refers: ASTM D3740-11 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Sep-2011
• Refers: ASTM D653-11 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Sep-2011
• Refers: ASTM D3740-10 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Mar-2010
• Refers: ASTM D653-09 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Jan-2009
• Refers: ASTM D653-08a - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Dec-2008
• Refers: ASTM D653-08 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Nov-2008
• Refers: ASTM D3740-08 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Mar-2008
• Refers: ASTM D6760-08 - Standard Test Method for Integrity Testing of Concrete Deep Foundations by Ultrasonic Crosshole Testing
• Effective Date: 01-Jan-2008

Overview

ASTM D8169/D8169M-18: Standard Test Methods for Deep Foundations Under Bi-Directional Static Axial Compressive Load provides internationally recognized procedures for testing deep foundation elements, often called “piles,” using an embedded bi-directional jack assembly. This bi-directional static axial compressive load test delivers direct measurements of pile behavior under load, supporting engineers in evaluating the load-bearing performance, efficiency, and long-term behavior of foundations in diverse soil and site conditions.

This ASTM standard applies to all deep foundations functioning similarly to driven piles, cast-in-place piles, or barrettes, regardless of installation method. The procedures outlined are essential for engineers, construction managers, and quality assurance professionals involved in geotechnical engineering and foundation design.

Key Topics

• Bi-directional Static Axial Compressive Load Test: The test method utilizes a jack placed inside the pile, measuring both side shear above the assembly and end bearing (plus any additional side shear) below it. This direct loading method enables detailed analysis of axial compressive resistance.
• Test Procedures: ASTM D8169/D8169M-18 includes two primary procedures:
  • Procedure A: Quick Test
  • Procedure B: Extended Test (optional, as approved by the engineer)
• Detailed Instrumentation Requirements: The standard specifies minimum apparatus and procedures for the reliable application and measurement of loads and pile movement, including requirements for calibration and safety.
• Performance Analysis: Test results help assess:
  • The distribution of resistance along the pile
  • The fully mobilized pile resistance
  • Load-displacement behavior for design or quality assurance
  • Prediction of constructed pile adequacy
• Factors Affecting Results: Pile installation method, material properties, site conditions, elapsed time, prior load cycles, and testing procedures are all identified as influential.
• Engineer Oversight: All deviations, special requirements, and overall test configuration must be approved by a licensed engineer.

Applications

Bi-directional static axial compressive load tests as defined by ASTM D8169/D8169M-18 are widely used in:

• Foundation Design Optimization: By providing separate measurement of pile segment response, engineers can refine designs, often leading to material savings through minimized pile length, diameter, or quantity while ensuring reliability.
• Quality Assurance and Control: The test enables the evaluation of pile performance at predetermined loads, supporting the validation of constructed piles for permanent installations.
• Assessment of Load Transfer Mechanisms: Understanding how load is shared between side shear and end bearing supports improved design and prediction of long-term settlement.
• Site-Specific Performance Evaluation: The standard’s methods apply to various deep foundation types across changing geotechnical conditions, making it valuable for bridges, high-rise buildings, offshore platforms, and other demanding applications.
• Regulatory Compliance: Following ASTM D8169/D8169M-18 aligns with international best practices, often essential for permitting and contract specifications.

Related Standards

The following referenced documents complement and extend the utility of ASTM D8169/D8169M-18:

• ASTM D1143/D1143M: Test Methods for Deep Foundations Under Static Axial Compressive Load
• ASTM D3689/D3689M: Test Methods for Deep Foundations Under Static Axial Tensile Load
• ASTM D5882: Test Method for Low Strain Impact Integrity Testing of Deep Foundations
• ASTM D6760: Integrity Testing of Concrete Deep Foundations by Ultrasonic Crosshole Testing
• ASTM D7949: Thermal Integrity Profiling of Concrete Deep Foundations
• ASME B30.1: Jacks
• ASME B40.100: Pressure Gauges and Gauge Attachments

By referencing and adhering to ASTM D8169/D8169M-18, professionals ensure precise, consistent, and internationally recognized evaluations of deep foundation performance, leading to safer, more reliable structures and optimized construction processes.

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: D8169/D8169M − 18
Standard Test Methods for
Deep Foundations Under Bi-Directional Static Axial
Compressive Load
This standard is issued under the fixed designation D8169/D8169M; 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 dures. The text of this standard references notes and footnotes
which provide explanatory material. These notes and footnotes
1.1 The test methods described in this standard measure the
(excluding those in tables and figures) shall not be considered
axial displacement of a single, deep foundation element when
as requirements of the standard. This standard also includes
loaded in bi-directional static axial compression using an
illustrations and appendixes intended only for explanatory or
embedded bi-directional jack assembly. These methods apply
advisory use.
to all deep foundations, referred to herein as “piles,” which
function in a manner similar to driven piles, cast in place piles,
1.7 Units—The values stated in either SI units or inch-
or barrettes, regardless of their method of installation. The test
pound units (presented in brackets) are to be regarded sepa-
results may not represent the long-term performance of a deep
rately as standard.The values stated in each system may not be
foundation.
exact equivalents; therefore, each system shall be used inde-
pendentlyoftheother.Combiningvaluesfromthetwosystems
1.2 This standard provides minimum requirements for test-
may result in non-conformance with the standard. Reporting of
ing deep foundations under bi-directional static axial compres-
test results in units other than SI shall not be regarded as
sive load. Plans, specifications, and/or provisions prepared by
nonconformance with this test method.
a qualified engineer may provide additional requirements and
procedures as needed to satisfy the objectives of a particular
1.8 The gravitational system of inch-pound units is used
test program. The engineer in charge of the foundation design,
when dealing with inch-pound units. In this system, the pound
referredtohereinastheengineer,shallapproveanydeviations,
(lbf) represents a unit of force (weight), while the unit for mass
deletions, or additions to the requirements of this standard.
isslugs.Therationalizedslugunitisnotgiven,unlessdynamic
(F=ma) calculations are involved.
1.3 This standard provides the following test procedures:
Procedure A Quick Test 9.2.1
1.9 All observed and calculated values shall conform to the
Procedure B Extended Test 9.2.2
guidelines for significant digits and rounding established in
(optional)
Practice D6026.
1.4 Apparatus and procedures herein designated “optional”
1.9.1 Theproceduresusedtospecifyhowdataarecollected,
may produce different test results and may be used only when
recorded and calculated in this standard are regarded as the
approved by the engineer. The word “shall” indicates a
industry standard. In addition, they are representative of the
mandatory provision, and the word “should” indicates a
significant digits that should generally be retained. The proce-
recommended or advisory provision. Imperative sentences
dures used do not consider material variation, purpose for
indicate mandatory provisions.
obtaining the data, special purpose studies, or any consider-
1.5 The engineer may use the results obtained from the test
ations for the user’s objectives; and it is common practice to
procedures in this standard to predict the actual performance
increase or reduce significant digits of reported data to be
and adequacy of piles used in the constructed foundation. See
commensuratewiththeseconsiderations.Itisbeyondthescope
Appendix X1 for comments regarding some of the factors
of this standard to consider significant digits used in analysis
influencing the interpretation of test results.
methods for engineering design.
1.6 A qualified engineer (specialty engineer, not to be
1.10 This standard offers an organized collection of infor-
confused with the foundation engineer as defined above) shall
mation or a series of options and does not recommend a
design and approve the load test configuration and test proce-
specific course of action. This document cannot replace edu-
cation or experience and should be used in conjunction with
professional judgment. Not all aspects of this guide may be
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
applicable in all circumstances. This ASTM standard is not
RockandisthedirectresponsibilityofSubcommitteeD18.11onDeepFoundations.
intended to represent or replace the standard of care by which
Current edition approved Jan. 1, 2018. Published February 2018. DOI: 10.1520/
D8169_D8169M-18. the adequacy of a given professional service must be judged,
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8169/D8169M − 18
nor should this document be applied without consideration of 3.2.3 bi-directional axial compressive load test, n—an axial
a project’s many unique aspects. The word “Standard” in the compressive load test performed on a deep foundation element
title of this document means only that the document has been by pressurizing an embedded jack assembly (see definition
approved through the ASTM consensus process. below), so that the foundation section above the jack assembly
moves upwards and the foundation section below the jack
1.11 This standard does not purport to address all of the
assembly moves downwards, each section providing reaction
safety concerns, if any, associated with its use. It is the
from which to load the other.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- 3.2.4 cast in-place pile, n—a deep foundation element made
mine the applicability of regulatory limitations prior to use. of cement grout or concrete and constructed in its final
1.12 This international standard was developed in accor- location, e.g., drilled shafts, bored piles, caissons, auger cast
dance with internationally recognized principles on standard- piles, pressure-injected footings, etc.
ization established in the Decision on Principles for the
3.2.5 deep foundation, n—a relatively slender structural
Development of International Standards, Guides and Recom-
element that transmits some or all of the load it supports to soil
mendations issued by the World Trade Organization Technical
or rock well below the ground surface (also referred to herein
Barriers to Trade (TBT) Committee.
as a “pile”), such as a steel pipe pile or concrete drilled shaft.
3.2.6 driven pile, n—a deep foundation element made of
2. Referenced Documents
preformed material with a predetermined shape and size and
2.1 ASTM Standards:
typicallyinstalledbyimpacthammering,vibrating,orpushing.
D653 Terminology Relating to Soil, Rock, and Contained
3.2.7 jack assembly, n—one or more bi-directional jacks
Fluids
arranged together with any plates to act in parallel symmetri-
D1143/D1143M Test Methods for Deep Foundations Under
cally around a central axis, which will be embedded within a
Static Axial Compressive Load
deep foundation element to apply a bi-directional compressive
D3689/D3689M Test Methods for Deep Foundations Under
load aligned with the central axis of the deep foundation
Static Axial Tensile Load
element.
D3740 Practice for Minimum Requirements for Agencies
Engaged in Testing and/or Inspection of Soil and Rock as 3.2.8 steel reinforcement, n—for the purpose of this
Used in Engineering Design and Construction Standard, this may consist of any steel assemblage or steel
D5882 Test Method for Low Strain Impact Integrity Testing member such as a rebar cage, channel frame, box beam,
of Deep Foundations wide-flange beam, etc., used to reinforce the concrete column,
D6026 Practice for Using Significant Digits in Geotechnical or in a non-production pile, to fix the jack(s) and instrumen-
Data tation in place.
D6760 Test Method for Integrity Testing of Concrete Deep
3.2.9 telltale rod, n—an unstrained metal rod extended
Foundations by Ultrasonic Crosshole Testing
through the test pile from a specific point within the pile to be
D7949 Test Methods for Thermal Integrity Profiling of
used as a reference from which to measure the change in the
Concrete Deep Foundations
length of the loaded pile section, or the absolute movement at
2.2 ASME Standards:
that specific point.
ASME B30.1 Jacks
3.2.10 wireline, n—a steel wire mounted with a constant
ASME B40.100 Pressure Gauges and Gauge Attachments
tensionforcebetweentwosupportsandusedasareferenceline
to read a scale indicating movement of the test pile.
3. Terminology
3.1 Definitions:
4. Significance and Use
3.1.1 For definitionsofcommontechnicaltermsusedinthis
4.1 The bi-directional axial compressive load test provides
standard, refer to Terminology D653.
separate, direct measurements of the pile side shear mobilized
3.2 Definitions of Terms Specific to This Standard:
above an embedded jack assembly and the pile end bearing
3.2.1 axial compressive capacity, n—the maximum axial
plus any side shear mobilized below the jack assembly. The
compressive load that a deep foundation can transfer to the soil
maximum mobilized pile resistance equals two times the
and rock around it at an acceptable axial movement.
maximum load applied by the jack assembly. Test results may
3.2.2 bi-directional jack, n—a specialized hydraulic jack
also provide information used to assess the distribution of side
that has a repeatable, linear load-pressure calibration over its
shear resistance along the pile, the amount of end bearing
expansion range.
mobilized at the pile bottom, and the long-term load-
displacement behavior.
2 4.2 The specified maximum test load should be consistent
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
with the engineer’s desired test outcome. For permanent
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
(working)piles,theengineermayrequirethatthemagnitudeof
the ASTM website.
applied test load be limited in order to measure the pile
Available from American Society of Mechanical Engineers (ASME), ASME
movement at a predetermined proof load as part of a quality
International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
www.asme.org. controlorqualityassuranceprogram.Teststhatattempttofully
D8169/D8169M − 18
economical, or code considerations may also result in bi-directional load
mobilize the axial compressive resistance of the test pile may
tests that are not intended to fully mobilize the axial resistance in some or
allow the engineer to improve the efficiency of the pile design
all sections of the pile. In these cases, interpretation of the bi-directional
by reducing the piling length, quantity, or size.
test may under-predict the total axial compressive capacity of the pile.
NOTE 5—The quality of the results produced by this test method are
4.3 The engineer and other interested parties may analyze
dependent on the competence of the personnel performing it, and the
the results of a bi-directional axial compressive load test to
suitability of the equipment and facilities used. Agencies that meet the
estimate the load versus movement behavior and the pile
criteria of Practice D3740 are generally considered capable of competent
capacity that would be measured during axial static compres-
and objective testing/sampling/ inspection/etc. Users of this test method
sive or tensile loading applied at the pile top (see Notes 1-3). are cautioned that compliance with Practice D3740 does not in itself
assure reliable results. Reliable results depend on many factors; Practice
Factors that may affect the pile response to axial static loading
D3740 provides a means of evaluating some of those factors.
during a static test include, but are not limited to the:
(1) pile installation equipment and procedures,
5. Test Foundation Preparation
(2) elapsed time since initial installation,
(3) pile material properties and dimensions,
5.1 Fig. 1 shows a typical schematic of an embedded jack
(4) type, density, strength, stratification, and groundwater assembly placed within a test pile in preparation for a bi-
conditions both adjacent to and beneath the pile,
directional axial compressive load test. The resultant line of
(5) test procedure, force of the jack assembly shall coincide with the central axis
(6) prior load cycles.
of the foundation element. During initial jack pressurization, a
fracture plane will form through the concrete surrounding the
NOTE 1—To estimate the load displacement curve for the pile as if it
jack assembly, and the pile reinforcement and instrumentation
were loaded in compression at the top (as in Test Methods D1143/
shall not restrain the subsequent expansion of the assembly
D1143M), the engineer may use strain and movement compatibility to
sum the pile capacity mobilized above and below the embedded jack after the fracture occurs.As indicated below, different types of
assembly for a given pile-top movement. This “top-load” curve will be
deep foundations require different methods of jack installation.
limited by the lesser of the displacement measured above or below the
Other methods and procedures are possible. The depth to the
embedded jack assembly. To obtain adequate minimum displacement
embedded jack and the test instrumentation installed within the
during the test, the engineer may wish to specify a maximum test load
pile shall be measured to the nearest 25 mm [1 in.] or less with
greater than the desired equivalent “top load”.
NOTE 2—Abi-directional load test applies the test load within the pile,
respect to a common fixed point near the pile top that will
resulting in internal pile stresses and pile displacements that differ from
remain accessible after completion of the pile installation.
those developed during a load test applied at the pile top. Bi-directional
testing will generally not test the structural suitability of a pile to support
NOTE 6—The engineer should assure that the capacity of the jack
a load as typically placed at the pile top. Structural defects near the pile
assembly can mobilize the desired pile capacity found above and below
top may go undetected unless separate integrity tests are performed prior
thejack.Testsperformedfordesignoptimizationshouldfullymobilizethe
toorafterbi-directionaltesting(seeNote8).Theanalysisofbi-directional
axial compressive capacity when possible.
loadtestresultstoestimatethepile-topmovementthatwouldbemeasured
5.2 For cast-in-place piles constructed by excavating an
byapplyingacompressiveloadatthetopofthepileshouldconsiderstrain
open hole in the ground, such as drilled shafts or bored piles,
compatibility and load-displacement behavior. ASTM D1143/D1143M
provides a standard test method for the direct measurement of pile top
position the jack assembly at the desired location within the
movement during an axial static compressive load applied at the pile top.
pilepriortoplacingthepileconcrete.Useasteelreinforcement
NOTE 3—The analysis of bi-directional load test results to estimate pile
cage, or a similar support frame, with centralizer devices to
displacements that would be measured by applying a tensile (uplift) load
maintain the location and orientation of the assembly during
at the top of the pile should consider strain and movement compatibility.
concrete placement. Obtain sound concrete around the assem-
Users of this standard are cautioned to interpret conservatively the tensile
capacity estimated from the analysis of a compressive load. ASTM
bly by using a fluid concrete mixture, placing concrete at a
D3689/D3689M provides a standard test method for the direct measure-
slow and steady rate, and providing adequate clearance around
ment of axial static tensile capacity.
the jack assembly to avoid restricting concrete flow and
4.4 For the purpose of fully mobilizing the axial compres-
trapping any sediments, drill fluid, or laitance. If the allowable
sive capacity, the engineer will usually locate the jack assem-
jack expansion is inadequate to compress sediments and
bly at a location within pile where the capacity above the
mobilize the planned end bearing Sediments and cuttings
assembly equals the capacity below it. A poorly chosen
should be removed from the pile bottom before concreting.
assembly location may result in excessive movement above or
This unremoved material may reduce the maximum possible
below the jack assembly, limiting the applied load and reduc-
test load since some or all the end bearing may not be
ing the usefulness of the test result. Determination of the
mobilized. The jack assembly should be placed a minimum
assembly’s location requires suitable site characterization,
distance of one-half pile diameter above the pile bottom, as
consideration of construction methods, and the proper applica-
needed to place sound concrete or grout below it. A jack
tion of engineering principles and judgement (see Note 4).
assembly placed along the pile length shall provide access to
Morecomplextestconfigurations,usingmultiplelevelsofjack
place concrete beneath the assembly. The engineer shall
assemblies, may provide a higher probability that the full
determine or at a minimum document what if any effect
resistanceofthepilealongitsentirelengthmaybedetermined.
construction procedures may have on the bi-directional test
Details regarding such complex arrangements are beyond the
results or the design assumptions.
scope of this standard.
NOTE 7—When testing a cast-in-place pile, the size, shape, material
NOTE 4—The bi-directional load test may not fully mobilize the axial composition and properties of the pile can influence the pile capacity and
compressive pile resistance in all sections of the pile. Practical, the interpretation of strain measurements described in Section 7.
D8169/D8169M − 18
FIG. 1 Schematic of Bi-Directional Load Test Instrumentation
Therefore, direct or indirect measurements of the pile size, shape, material
5.5 Use a jack assembly containing a single jack when
composition and properties versus depth are recommended.
possible. Multi-jack assemblies shall be designed to load the
5.3 For cast-in-place piles constructed by placing grout or pile symmetrically about its axis, typically using jacks of the
concreteduringwithdrawalofanauger,thejackassemblyshall same make, model, and capacity with each jack having
beattachedtoasteelreinforcement,orasimilarsupportframe, independent pressure supply hoses or pipes.
and then placed into the fluid grout or concrete to the desired
5.6 Unless approved otherwise by a qualified test engineer,
location. Use centralizing devices to avoid damaging the jack
install a minimum of two hydraulic hoses or pipes (input and
or altering the size and shape of the pile. Provide a minimum
return) extending from the pile top to the jack assembly. To
clearance between the jack and the sidewalls of the excavation
confirm the hydraulic flow to each jack and to isolate potential
of the lesser of 75 mm [3 in.] or 8 times the diameter of largest
pressure leaks during the test, two hoses or pipes extending
coarse aggregate unless otherwise specified by the engineer.
from the pile top are recommended for each individual jack.
NOTE 8—Deep foundations sometimes include hidden defects that may Jacks directly connected together within an assembly in series
go unnoticed prior to static testing. Low strain integrity tests (D5882),
shall be tested together to verify flow continuity and check for
ultrasonic crosshole integrity tests (D6760), thermal integrity (D7949)or
pressure leaks. Alternatively, jacks may be connected in
similar integrity tests may provide useful pre-test information about the
parallel using a manifold. Flow and pressure to each jack can
test pile. However, the embedded jack assembly typically, but may not
be directly verified. To limit potential leaks, the hoses or pipes
always, appear as an anomaly itself. The engineer should use caution
when using such tests and the results to conclude that an anomaly exists should not include unnecessary fittings or connections within
near the assembly as opposed to being the anomaly. In most cases the
thepile.Eachhoseorpipeshallbeclearlymarkedateachjack,
initial part of the load test itself is the best indicator of whether such an
at both sides of any connections, and at the pile top to identify
anomaly is significant or likely to affect the test.
the jack connected to it.
5.4 For driven, pushed, or screwed piles, the jack assembly
5.7 Install a minimum of two pipes or tubes to vent the
is usually installed during the manufacture of the pile. The pile
location at which the jack assembly will cause the pile to break
is then installed as per normal procedures. Alternatively, if
during the test.
these piles have a full-length central void (for example, pipe,
cylinder, etc.), any material inside the pile may be excavated 5.8 Permanent (working) piles may use the vent pipes or
after installation and the jack assembly may be installed as tubes for post-test grouting of the fracture plane created in the
described in 5.2. pile by the expanded jack assembly. The hydraulic hoses or
D8169/D8169M − 18
pipesinstalledforeachjackmaybeusedtogrouttheexpanded by at least 10 %.The ram of each bi-directional jack shall have
jack(s) with a fluid, high-strength, non-shrink grout as ap- aminimumtravelof150mm[6in.]unlessotherwiseapproved
proved by a qualified engineer. by the engineer. Each bi-directional jack shall have a pressure
versus force calibration demonstrating a maximum linearity
5.9 Excavateoraddfilltothegroundsurfacearoundthetest
errorlessthanorequalto2 %ofthemaximumanticipatedjack
pile to the final design elevation as directed by a qualified
load to at least 100 mm [4 in.] of expansion. At a minimum,
engineer.
each jack shall include a calibration performed at ram exten-
5.10 Cut off or build up the test pile or test pile steel as
sions of approximately 25 mm [1 in.] and 100 mm [4 in.] or
necessary to permit the placement, use, and operation of the
greater. The design of the embedded jack shall maintain its
testing equipment and instrumentation. Remove any damaged
pressure versus force calibration and load linearity up to a tilt
or unsound material from the pile top as required to place the
of 1 degree from its axis, which shall on request from the
test instrumentation.
engineer be demonstrated during calibration. For safety
reasons,thejackassemblyshouldbepressurizedusinghydrau-
5.11 When temporarily dewatering a test site, maintain the
groundwater level as near to a fixed elevation as possible for lic fluid, for example, oil, water, or both.
the duration of the test as directed by the engineer.
7.2.2 Assemble the bi-directional jack assembly with steel
bearing plates, stiffeners, or equivalent as needed to distribute
6. Safety Requirements
the jack load evenly over the pile cross-section. Properly
distributed load shall yield a uniform cross-sectional distribu-
6.1 All operations in connection with pile load testing shall
tion of the axial load at no more than two pile diameters above
be carried out in such a manner so as to minimize, avoid, or
andbelowtheassembly.Consultaqualifiedstructuralengineer
eliminate the exposure of people to hazard. The following
as needed. Measure and record the distance from the pile top
safety rules are in addition to general safety requirements
reference to the top and bottom of the jack assembly to the
applicable to construction operations: (Also see 1.11.)
nearest 25 mm [1 in.] or less.
6.1.1 Provide a stable and level work area around the test
pile. Keep all test and adjacent work areas, walkways, 7.2.3 Weld or lock the jack assembly so that it remains
platforms, etc. clear of scrap, debris, small tools, and accumu- closed during handling and installation in the pile. The welds
lations of snow, ice, mud, grease, oil, or other slippery or locks shall be designed so that they may be disengaged
substances. completely (no resistance to expansion) prior to testing or to
6.1.2 Provide temporary devices as needed to keep the provide no resistance after 1 mm [0.04 in.] or less of assembly
embedded jack assembly safely closed during handling and expansion. When placed as an integral part of the steel
placement in the test pile. When placing the jack assembly as reinforcement in a cast in-place pile, the jack assembly and its
part of the steel reinforcement, provide adequate connections connection to the steel reinforcement shall be designed to
between the steel reinforcement and the jack assembly to safely withstand handling and placement stresses. A jack
maintain the stability and integrity of the overall steel rein- assembly cast into a driven pile shall include anchorage that
forcement during its handling and placement. Use multiple will safely withstand handling and driving stresses.
lifting connections as required to prevent permanent distortion
7.2.4 Bi-directional jacks that will open within soil, espe-
of the steel reinforcement and provide safe handling.
cially when installed in a driven pile, may include a plate
6.1.3 Loads shall not be hoisted, swung, or suspended over
around the pile perimeter that covers the opening between the
test personnel and shall be controlled by tag lines.
load plates to minimize disturbance of the surrounding soil
6.1.4 Permit only authorized personnel within the immedi-
during installation and testing.
ate test area and only as necessary to monitor test equipment.
7.2.5 The pump(s) and any hoses, pipes, fittings, pressure
As best as is possible, locate the pumping apparatus and the
gauges and pressure sensors used to pressurize the jack
hoses connecting it to the jack assembly a safe distance away
assembly shall be rated to a minimum safe pressure corre-
from test personnel, load cell readouts, data loggers, and test
sponding to the nominal capacity of the jack assembly.
monitoring equipment.
7.2.6 Unless otherwise approved by the engineer, measure
the pressure in the jack assembly using pressure gauges or
7. Apparatus and Preparation for Applying and
sensors with a range greater than or equal to the rated pressure
Measuring Loads
of the jack assembly and provide at least two measurements of
7.1 General:
the pressure in the jack assembly during testing, including the
7.1.1 A qualified structural engineer shall design and ap-
pressure applied on the input hydraulic line(s) and the pressure
prove the loading apparatus or reaction of any kind if any part
in the return line(s). Pressure gauges and pressure sensors shall
thereof extends to the ground surface or is likely to have any
have minimum graduations less than or equal to 1 % of the
effect on surface structures or cause bulk ground action.
maximum anticipated pressure and shall conform to ASME
B40.100 or similar international standards. When used for
7.2 Bi-directional Jacks, Pressure Gauges, and Pressure
controlofthetest,pressuresensoroutputinunitsofpressureor
Sensors:
calibrated load shall be displayed in real-time during the test.
7.2.1 For the bi-directional load test, the maximum load
applied by the embedded jack assembly will be half of the 7.2.7 If specified by the engineer, and when the specified
specifiedmaximumtestload.Theratednominalcapacityofthe maximum test load exceeds 4500 kN [1000 kips], install
jack assembly shall exceed the maximum anticipated jack load instrumentation within the pile that can be used to indicate the
D8169/D8169M − 18
load applied by the embedded jack assembly. This instrumen- stiffness,andcrossbracingtoprovidestablesupportforthetest
tation may consist of strain gauges as described in 8.6, or less instrumentation and to minimize vibrations that may affect the
commonly, embedded, sacrificial load cells. If used, each load measurement of the pile movement. One end of each beam
cell shall have a calibration to at least its maximum anticipated shall be free to move along its axis as the beam length changes
measured load, performed within the twelve months prior to
with temperature variations. Supports for reference beams and
the load test. Each calibration shall show a maximum linearity wirelinesshallbeisolatedfrommovingwaterandwaveaction.
error less than or equal to 2 % of the load cell’s maximum
8.1.5 Provide a tarp or shelter to prevent direct sunlight and
anticipated measured load.
precipitation from affecting the measuring and reference sys-
7.2.8 Each embedded jack, pressure gauge, pressure sensor,
tems.
andloadcellshallbeplainlymarkedbyauniqueserialnumber
8.1.6 Dial and electronic displacement indicators shall con-
and shall have a calibration versus a traceable standard
form to ASME B89.1.10.M Dial Indicators (For Linear Mea-
performed no more than twelve months prior to the test that
surements) or similar international Standards. Electronic indi-
satisfies the above specifications to at least the maximum
cator movement shall be displayed in real-time during the test.
anticipated jack load. The engineer should specify more recent
Dial indicators and electronic displacement indicators shall be
calibration when recommended by the manufacturer, or in the
in good working condition and shall have a full range calibra-
event of rough handling or harsh storage conditions. Furnish
tion within twelve months prior to each test. Furnish calibra-
the calibration reports prior to performing a load test. Calibra-
tionreportspriortoperformingatest,includingtheambientair
tion reports shall include the ambient temperature.
temperature during calibration. Provide a smooth bearing
7.2.9 Strain gauges are recommended at stratigraphic eleva-
surface for the indicator stem perpendicular to the direction of
tions to assess the load in the pile, to calculate the load transfer
stem travel, such as a small, lubricated, glass plate glued in
along the pile length. See 8.6 for more detail.
place (if applicable, not applicable for in-line set-ups). Dis-
NOTE9—Bi-directionaltestsofworkingpilesmayseekonlytoevaluate placement indicators used for measuring pile movements shall
the pile displacement at a pre planned proof load. The engineer should
have a minimum travel of 100 mm [4 in.] and minimum
assess the economic benefit of using strain gauges for working piles.
graduations of 0.1 mm [0.01 in.] or less, with similar accuracy
7.2.10 The hydraulic pump used to pressurize each jack or
or better, and shall be read to the nearest graduation or less.
the jack assembly shall be monitored and controlled by
Provide greater travel, stem extensions, or calibrated blocks if
qualified personnel at all times, either in person or by remote
larger displacements are anticipated (adjust gradations and
access. Automated and remotely controlled loading systems
accuracy proportionally as needed ). Displacement indicators
shall include a clearly marked mechanical override to safely
used for measuring pile compression (see 8.5) shall have a
reduce hydraulic pressure in an emergency.
travel of at least 25 mm [1 in.] and minimum graduations of
0.01 mm [0.0005 in.] or less, with similar accuracy or better,
8. Apparatus and Preparation for Measuring Movement
and shall be read to the nearest graduation or less.
and Strain
8.1.7 Optical, laser, or digital survey levels may be used for
secondarypiletopaxialmovementmeasurements(see8.2)and
8.1 General:
to verify reference movements. Survey levels shall be in good
8.1.1 At a minimum, measure the pile top movement as
working condition and shall have a calibration within twelve
describedin8.2andthemovementofthetopandbottomofthe
months prior to each test. Furnish calibration reports prior to
jack assembly as described in 8.3. The engineer may also
performing a test, including the ambient air temperature during
require optional direct measurements of the pile bottom
calibration. These levels shall have an accuracy of 3 mm at 30
movement, the pile compression above or below the jack
m [0.13 in. at 100 ft] or better and shall be self leveling
assembly, or the strain in the pile to help interpret and verify
(automatic). Scales, targets, detectors, or staffs used with these
the pile behavior.When the jack assembly is located more than
levels for shall have a length no less than 150 mm [6 in.] and
1 m [3 ft] above the bottom of the pile, measure the movement
minimum graduations of 0.5 mm [0.02 in.] or less, with similar
of the pile bottom as described in 8.4.
accuracy or better, and shall be read to the nearest 0.25 mm
8.1.2 When positioning the test instrumentation and
[0.01 in.] or less. Survey rods shall have minimum graduations
references, the load test provider shall consider the anticipated
of 1 mm [0.01 ft] or less, with similar accuracy or better, and
testpilemovementtominimizerepositioningrequirementsand
shall be read to the nearest 0.25 mm [0.001 ft].
the risk of damage during the test.
8.1.3 Report upward pile movement as positive and down- 8.1.8 Digital survey levels may be used for primary move-
ward movement as negative. Report pile compression as ment measurements (see 8.2) provided they have an accuracy
positive and expansion as negative. Report jack assembly of 0.25 mm at 30 m [0.01 in at 100 ft] or better and are self
expansion as positive and closure as negative. leveling (automatic). Digital survey levels shall be in good
8.1.4 Reference beams and wirelines, if used, shall have working condition and shall have a calibration within twelve
supports firmly embedded in the ground at a clear distance months prior to each test. Furnish calibration reports prior to
from the test pile of at least five times the diameter of the test performing a test, including the ambient air temperature during
pile but not less than 2.5 m [8 ft]. Depending on the size and calibration. Targets used with these levels shall have a length
height of the pile top, orient a single reference beam across the no less than 150 mm [6 in.] and provide for a reading precision
pile top or two parallel reference beams, one on each side of of 0.25 mm [0.01 in.] or less, with similar accuracy or better.
the test pile. Reference beams shall have adequate strength, The movement from digital survey levels shall be displayed in
D8169/D8169M − 18
real-time during the test. Optical and laser survey levels shall of telltale system that provides an equivalent measurement of
not be used for primary pile top measurements. axial movement or compression.
8.1.9 Unstrained telltale rods, with a typical diameter of 6
8.1.11 Identify and mark each displacement indicator, scale,
mm[0.25in.],maybeusedtomeasuretheaxialpilemovement target, detector, staff, and reference point used during the test
or the axial compression within the pile (Figs. 1-4). Install the
with reference numbers or letters clearly visible to test person-
telltale rods in an open sheath or casing (pipe) having an inside nel.
diameter approximately two times the telltale rod diameter to
8.1.12 Indicators, scales, or reference points attached to the
insure free rod movement during the test (hereinafter collec-
test pile, reference beam, or other references shall be firmly
tively referred to as a telltale assembly). Use a displacement
affixed to prevent slippage during the test. Unless otherwise
indicator with its stem parallel to the pile axis to measure the
approved by the engineer, verify that all primary reference
relative movement between the rod and the pile top or the
points do not move during the test by using a surveyor’s level
reference beam. Mount a smooth bearing surface on the telltale
to take readings on a survey rod or a scale with reference to a
rod perpendicular to the rod for the indicator stem, such as a
permanent benchmark located outside of the immediate test
small, lubricated, glass plate clamped or glued in place.
area (greater than 5 pile diameters).
Alternately, attach an axial tension displacement indicator
8.2 Pile Top Axial Movements (Figs. 3 and 4):
directly to the telltale rod and affix the other end to a rigid
8.2.1 General—Unless otherwise specified, all axial com-
reference to measure the axial movement of the rod. Install a
pressiveloadtestsshallincluderedundantmeasurementsofthe
single telltale assembly on the pile axis, or install them in pairs
axialmovementofthetopofthetestpilewithrespecttoafixed
at the same elevation to obtain an average measurement on the
reference at or above the ground surface. These measurements
pile axis, with the telltale assemblies oriented diametrically
shall include a primary measurement system and at least one
oppositeeachotherandequidistantfromandparalleltothepile
redundant, secondary system as described above and below.
axis.
The primary and secondary systems may be identical provided
8.1.10 Fortestpileswithadiameterof1.8m[6ft]orlarger,
they are completely redundant.
install a minimum of two such pairs at each elevation as a
check of the average measurements, ideally with one pair NOTE 10—Use the redundant secondary system(s) to check the pile top
movement data and provide continuity when the primary measuring
orthogonal to the other. The telltale rods shall have a rounded
system is disturbed or reset for additional movement.
or pointed tip that bears on a clean steel plate affixed within the
pile or shall be threaded into a nut affixed within the pile or 8.2.2 Digital Survey Level—A digital survey level may be
equivalent mechanism. Prior to installation in the pile, clean used as a primary or a secondary system to measure pile top
the telltale rods, and oil them. Provide centralizers for the rods axial movement if readings can be automatically recorded and
at the pile top to restrain lateral movement but not axial displayed at least every 60 seconds.Asingle pile top measure-
movement. Measure and record the distance from the pile top ment point shall be located on the axis of the pile, or two
reference to the termination point of each rod to the nearest 25 measurement points shall be located axisymmetric to each
mm [1 in.] or less. The engineer may also specify another type other. The level shall be mounted on a survey tripod or other
FIG. 2 Schematic of Embedded Jack Movements
D8169/D8169M − 18
FIG. 3 Schematic of Instrumentation for Measuring Axial Pile Movements (Single survey device and target shown for clarity.)
FIG. 4 Alternate Schematic of Instrumentation for Measuring Axial Pile Movements
object with a fixed elevation (for example, driven pile) outside 8.2.3 Optical or Laser Survey Level—A single survey level
of the immediate test area and shall reference a stable bench- orlasermaybeusedonlyasasecondarysystemtomeasurethe
mark located outside of the immediate test area. The level may axial movement of a scale, target, detector, staff, or survey rod
also be mounted directly on top of the test pile with a stable mountedonthetopofthetestpileandparallelwithitsaxis(see
measurement point and a benchmark located outside of the Fig. 3).Asingle pile top measurement point shall be located on
immediate test area. the axis of the pile, or two measurement points shall be located
D8169/D8169M − 18
axisymmetric to each other and equidistant from the center of and bottom of the jack assembly to the nearest 0.1 mm [0.01
the pile.The level shall be mounted on a survey tripod or other in.] or less. Reference the telltale rods to the top of the pile or
object with a fixed elevation (for example, driven pile) outside to a reference beam system.
of the immediate test area and shall reference a stable bench- 8.3.3 Direct Jack Expansion Indicator Measurement—Asan
mark located outside of the immediate test area. alternate to 8.3.2, install electronic displacement indicators in
the pile as shown in Fig. 1 to directly measure the jack
8.2.4 Displacement Indicators—Displacement indicators
assembly expansion. These electronic displacement indicators
may be used as a primary or secondary system to measure
shallmeettherequirementsof8.1,shallhaveaminimumtravel
pile-top axial movement with respect to one or more reference
that exceeds the maximum anticipated jack assembly
beams. The indicator stem(s) shall be oriented parallel to the
expansion, and shall measure the assembly expansion to the
pile axis. A single indicator may be mounted on a reference
nearest0.1mm[0.01in.]orless.Installaminimumofonepair
beam to measure axial movement at the center of the test pile.
Otherwise, the indicators shall be mounted on the reference ofindicators,withtheindicatorsineachpairorienteddiametri-
cally opposite each other and equidistant from and parallel to
beam(s) in pairs to bear on the pile top at opposing axisym-
metric points.Alternatively, mount paired indicators on oppos- the pile axis. For test piles that have a diameter of 1.8 m [6 ft]
or larger, a minimum of two such pairs of indicators shall be
ing axisymmetric points to bear on the reference beam(s) at
opposing axisymmetric points. This alternate is more sensitive used as a redundant check of the measurements, ideally with
one pair orthogonal to the other. In addition, use at least one
to pile tilt and the gauge locations because the gauges move
with the pile. During the test, use a level or laser with scales, pair of telltale rods extending from the pile top to the top of the
jack assembly as specified in 8.5 to measure the pile compres-
targets, detectors, or staffs to measure the movement of the
reference beam relative to a stable benchmark located outside sion above the jack assembly (with a minimum of two pairs for
test piles that have a diameter of 1.8 m [6 ft] or larger).
of the immediate test area. It is possible to reverse the gauge(s)
so they are mounted on the pile top and their measurement Calculate the movement of the top of the jack assembly by
adding the pile top movement from 8.2 to the pile compression
stems on the reference beam. This arrangement should be used
above the jack assembly. Calculate the movement of the
only for good reason and by a qualified test engineer.
bottom of the jack assembly by subtracting the assembly
8.2.5 Wireline, Mirror, and Scale—Wirelines may only be
expansion from the movement of the top of the jack assembly.
used as a secondary measurement system to measure pile top
8.3.4 Other Types of Measurement Systems (optional)—The
movement. Orient two wirelines parallel to each other and
engineer may specify another type of measurement system
perpendiculartoandlocatedonoppositesidesequidistantfrom
satisfying the basic requirements of 8.3.
the axis of the test pile in a direction that permits placing the
wireline supports as far as practicable from the test pile. The
8.4 Pile Bottom Movement Indicators (optional):
wirelines shall include a weight or spring to maintain a
8.4.1 Telltale Rod Measurements—Install telltale rods to
constant tension force in the wire, so that, when plucked or
directly measure the movement of the bottom of the pile that
tapped, the wireline will return to its original position. Clean,
meet the requirements of 8.1. Displacement indicators used to
uncoated steel wire with a diameter of 0.25 mm [0.01 in.] or
measure these movements shall meet the requirements of 8.1,
less for the wirelines is recommended. Each wireline shall pass
shall have a minimum travel that exceeds the maximum
across, and remain clear of, a scale mounted on the test pile
anticipated pile bottom movement, and shall measure the axial
parallel to the axis of the pile or pile group. Mount the scale on
movement of the pile bottom to the nearest 0.1 mm [0.01 in.]
a mirror affixed to the test pile and use the wireline as a
or less. Reference the telltale rods to the top of the pile or to a
reference line to read the scale. Use the mirror to eliminate
reference beam system. Alternatively, measure the pile com-
parallax error in the scale reading by lining up the wire its
pression below the jack assembly directly as described in 8.5
image in the mirror. Align the wire not more than 13 mm [0.5
and then
...