ASTM D4186/D4186M-20

Standard Test Method for One-Dimensional Consolidation Properties of Saturated Cohesive Soils Using Controlled-Strain Loading

SIGNIFICANCE AND USE
5.1 Information concerning magnitude of compression and rate-of-consolidation of soil is essential in the design of earth structures and earth supported structures. The results of this test method may be used to analyze or estimate one-dimensional settlements, rates of settlement associated with the dissipation of excess pore-water pressure, and rates of fluid transport due to hydraulic gradients. This test method does not provide information concerning the rate of secondary compression.  
5.2 Strain Rate Effects:  
5.2.1 It is recognized that the stress-strain results of consolidation tests are strain rate dependent. Strain rates are limited in this test method by specification of the acceptable magnitudes of the base excess pressure ratio during the loading phase. This specification provides comparable results to the 100 % consolidation (end of primary) compression behavior obtained using Test Method D2435.  
5.2.2 Field strain rates vary greatly with time, depth below the loaded area, and radial distance from the loaded area. Field strain rates during consolidation processes are generally much slower than laboratory strain rates and cannot be accurately determined or predicted. For these reasons, it is not practical to replicate the field strain rates with the laboratory test strain rate.  
5.3 Temperature Effects:  
5.3.1 Temperature affects the rate parameters such as hydraulic conductivity and the coefficient of consolidation. The primary cause of temperature effects is due to the changes in pore fluid viscosity, but soil sensitivity may also be important. This test method provides results under room temperature conditions, corrections may be required to account for specific field conditions. Such corrections are beyond the scope of this test method. Special accommodation may be made to replicate field temperature conditions and still be in conformance with this test method.  
5.4 Saturation Effects:  
5.4.1 This test method may not be used to measur...
SCOPE
1.1 This test method is for the determination of the magnitude and rate-of-consolidation of saturated cohesive soils using continuous controlled-strain axial compression. The specimen is restrained laterally and drained axially to one surface. The axial force and base excess pressure are measured during the deformation process. Controlled strain compression is typically referred to as constant rate-of-strain (CRS) testing.  
1.2 This test method provides for the calculation of total and effective axial stresses, and axial strain from the measurement of axial force, axial deformation, chamber pressure, and base excess pressure. The effective stress is computed using steady state equations.  
1.3 This test method provides for the calculation of the coefficient of consolidation and the hydraulic conductivity throughout the loading process. These values are also based on steady state equations.  
1.4 This test method makes use of steady state equations resulting from a theory formulated under particular assumptions. Subsection 5.5 presents these assumptions.  
1.5 The behavior of cohesive soils is strain rate dependent and hence the results of a CRS test are sensitive to the imposed rate of strain. This test method imposes limits on the strain rate to provide comparable results to the incremental consolidation test (Test Method D2435).  
1.6 The determination of the rate and magnitude of consolidation of soil when it is subjected to incremental loading is covered by Test Method D2435.  
1.7 This test method applies to intact (Group C and Group D of Practice D4220), remolded, or laboratory reconstituted samples.  
1.8 This test method is most often used for materials of relatively low hydraulic conductivity that generate measurable excess base pressures. It may be used to measure the compression behavior of essentially free draining soils but will not provide a measure of the hydraulic conductivity or coefficient of co...

General Information

• Status: Historical
• Publication Date: 31-Oct-2020
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.05 - Strength and Compressibility of Soils

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D4186/D4186M − 20
Standard Test Method for
One-Dimensional Consolidation Properties of Saturated
1
Cohesive Soils Using Controlled-Strain Loading
This standard is issued under the fixed designation D4186/D4186M; 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* excess base pressures. It may be used to measure the compres-
sion behavior of essentially free draining soils but will not
1.1 This test method is for the determination of the magni-
provide a measure of the hydraulic conductivity or coefficient
tudeandrate-of-consolidationofsaturatedcohesivesoilsusing
of consolidation.
continuous controlled-strain axial compression. The specimen
is restrained laterally and drained axially to one surface. The 1.9 All recorded and calculated values shall conform to the
axial force and base excess pressure are measured during the
guideforsignificantdigitsandroundingestablishedinPractice
deformationprocess.Controlledstraincompressionistypically D6026, unless superseded by this test method. The significant
referred to as constant rate-of-strain (CRS) testing.
digits specified throughout this standard are based on the
assumptionthatdatawillbecollectedoveranaxialstressrange
1.2 Thistestmethodprovidesforthecalculationoftotaland
from 1% of the maximum stress to the maximum stress value.
effective axial stresses, and axial strain from the measurement
1.9.1 Theproceduresusedtospecifyhowdataarecollected/
of axial force, axial deformation, chamber pressure, and base
recorded and calculated in this standard are regarded as the
excess pressure. The effective stress is computed using steady
industry standard. In addition, they are representative of the
state equations.
significant digits that should generally be retained. The proce-
1.3 This test method provides for the calculation of the
dures used do not consider material variation, purpose for
coefficient of consolidation and the hydraulic conductivity
obtaining the data, special purpose studies, or any consider-
throughout the loading process.These values are also based on
ations for the user’s objectives; and it is common practice to
steady state equations.
increase or reduce significant digits of reported data to be
1.4 This test method makes use of steady state equations commensuratewiththeseconsiderations.Itisbeyondthescope
resulting from a theory formulated under particular assump- of this standard to consider significant digits used in analysis
tions. Subsection 5.5 presents these assumptions. methods for engineering design.
1.9.2 Measurements made to more significant digits or
1.5 The behavior of cohesive soils is strain rate dependent
better sensitivity than specified in this standard shall not be
andhencetheresultsofaCRStestaresensitivetotheimposed
regarded a non-conformance with this standard.
rateofstrain.Thistestmethodimposeslimitsonthestrainrate
to provide comparable results to the incremental consolidation
1.10 Units—The values stated in either SI units or inch-
test (Test Method D2435).
poundunits[giveninbrackets]aretoberegardedseparatelyas
standard. The values stated in each system may not be exact
1.6 The determination of the rate and magnitude of consoli-
equivalents;therefore,eachsystemshallbeusedindependently
dation of soil when it is subjected to incremental loading is
of the other. Combining values from the two systems may
covered by Test Method D2435.
result in non-conformance with the standard. Reporting of test
1.7 This test method applies to intact (Group C and Group
results in units other than SI shall not be regarded as noncon-
D of Practice D4220), remolded, or laboratory reconstituted
formance with this standard.
samples.
1.10.1 The gravitational system is used when working with
1.8 This test method is most often used for materials of
inch-pound units. In this system, the pound (lbf) represents a
relatively low hydraulic conductivity that generate measurable
unit of force (weight), while the unit for mass is slugs. The
rationalized slug unit is not given, unless dynamic (F = ma)
calculations are involved.
1
1.10.2 Itiscommonpracticeintheengineering/construction
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
Rock and is the direct responsibility of Subcommittee D18.05 on Strength and
profession to concurrently use pounds to represent both a unit
Compressibility of Soils.
of mass (lbm) and of force (lbf). This implicitly combines two
Current edition approved Nov. 1, 2020. Published November 2020. Originally
ɛ1
separate systems of units; that is, the absolute system and the
approved in 1982. Last previous editio
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: D4186/D4186M − 12 D4186/D4186M − 20
Standard Test Method for
One-Dimensional Consolidation Properties of Saturated
1
Cohesive Soils Using Controlled-Strain Loading
This standard is issued under the fixed designation D4186/D4186M; 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
ε NOTE—Editorially corrected Eq X1.3 in June 2014.
1. Scope*
1.1 This test method is for the determination of the magnitude and rate-of-consolidation of saturated cohesive soils using
continuous controlled-strain axial compression. The specimen is restrained laterally and drained axially to one surface. The axial
force and base excess pressure are measured during the deformation process. Controlled strain compression is typically referred
to as constant rate-of-strain (CRS) testing.
1.2 This test method provides for the calculation of total and effective axial stresses, and axial strain from the measurement of axial
force, axial deformation, chamber pressure, and base excess pressure. The effective stress is computed using steady state equations.
1.3 This test method provides for the calculation of the coefficient of consolidation and the hydraulic conductivity throughout the
loading process. These values are also based on steady state equations.
1.4 This test method makes use of steady state equations resulting from a theory formulated under particular assumptions.
SectionSubsection 5.5 presents these assumptions.
1.5 The behavior of cohesive soils is strain rate dependent and hence the results of a CRS test are sensitive to the imposed rate
of strain. This test method imposes limits on the strain rate to provide comparable results to the incremental consolidation test (Test
Method D2435).
1.6 The determination of the rate and magnitude of consolidation of soil when it is subjected to incremental loading is covered
by Test Method D2435.
1.7 This test method applies to intact (Group C and Group D of Practice D4220), remolded, or laboratory reconstituted samples.
1.8 This test method is most often used for materials of relatively low hydraulic conductivity that generate measurable excess base
pressures. It may be used to measure the compression behavior of essentially free draining soils but will not provide a measure
of the hydraulic conductivity or coefficient of consolidation.
1.9 All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026,
1
This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.05 on Strength and
Compressibility of Soils.
Current edition approved Nov. 1, 2012Nov. 1, 2020. Published December 2012November 2020. Originally approved in 1982. Last previous edition approved in 20062012
ɛ1
as D4186 – 06.D4186 – 12 . DOI: 10.1520/D4186_D4186M-12E01.10.1520/D4186_D4186M-20.
*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
1

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D4186/D4186M − 20
unless superseded by this test method. The significant digits specified throughout this standard are based on the assumption that
data will be collected over an axial stress range from 1% of the maximum stress to the maximum stress value.
1.9.1 The procedures used to specify how data are collected/recorded and calculated in this standard are regarded as the industry
standard. In addition, they are representative of the significant digits that should generally be retained. The procedures used do not
consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives;
and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations.
It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design.
1.9.2 Measurements made to more significant digits or better sensitivity than specified in this standard shall not be regarded a
non-conformance with this standard.
1.10 Units—The values stated in either SI units or inch-pound units [given in brackets] are to be regarded separately as stan
...