D18.09 - Cyclic and Dynamic Properties of Soils

SIGNIFICANCE AND USE
5.1 The equivalent elastic shear modulus and damping capacity of a given soil, as measured by the resonant column technique herein described, depend upon the strain amplitude of vibration, the state of effective stress, and the void ratio of the soil, temperature, time, etc. Since the application and control of the static axial and lateral stresses and the void ratio are not prescribed in these methods, the applicability of the results to field conditions will depend on the degree to which the application and control of the static axial and lateral stresses and the void ratio, as well as other parameters such as soil structure, duplicate field conditions. The techniques used to simulate field conditions depend on many factors and it is up to the engineer to decide on which techniques apply to a given situation and soil type. The results of these tests are useful for calculations involving soil-structure interaction and seismic response of soil deposits.
Note 1: The quality of the results produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.
SCOPE
1.1 These test methods cover the determination of shear modulus and shear damping as a function of shear strain amplitude for solid cylindrical specimens of soil in intact and reconstituted conditions by torsional vibration using resonant column devices. The vibration of the specimen may be superposed on a controlled static state of stress in the specimen. The vibration apparatus and specimen may be enclosed in a triaxial chamber and subjected to an all-around pressure and axial load. In addition, the specimen may be subjected to other controlled conditions (for example, pore-water pressure, degree of saturation, temperature). These test methods of modulus and damping determination are considered nondestructive when the shear strain amplitudes of vibration are less than 10–2 % (10–4 in./in.), and many measurements may be made on the same specimen and with various states of static stress.  
1.2 Two device configurations are covered by these test methods: Device Type 1 where a known torque is applied to the top of the specimen and the resulting rotational motion is measured at the top of the specimen, and Device Type 2 where an uncalibrated torque is applied to the top of the specimen and the torque transmitted through the specimen is measured by a torque transducer at the base of the specimen. For both types of devices, the torque is applied to the active end (usually top) of the specimen and the rotational motion also is measured at the active end of the specimen.  
1.3 These test methods are limited to the determination of the shear modulus and shear damping, the necessary vibration, and specimen preparation procedures related to the vibration, etc., and do not cover the application, measurement, or control of the axial and lateral static normal stresses. The latter procedures may be covered by, but are not limited to, Test Method D2850, D4767, or D7181.  
1.4 Significant Digits—All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026.  
1.4.1 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 objec...

SIGNIFICANCE AND USE
5.1 Cyclic direct simple shear strength test results are used most often for evaluating the ability of a soil to resist shear stresses induced in a soil mass during earthquake loading, offshore storm loading, etc.  
5.2 In this test, the cyclic strength is measured under constant volume conditions that are equivalent to undrained conditions; hence, the test is applicable to field conditions in which the soils have consolidated under one set of stresses, and then are subjected to changes in stress/strain without time for further drainage to take place.  
5.3 The cyclic strength is a function of many factors including density, confining pressure, stress history, grain structure, specimen preparation procedure, frequency, and characteristics of the cyclic loading applied. Therefore, test factors shall be considered during evaluation of test results.  
5.4 The state of stress within the direct simple shear specimen is not sufficiently defined nor uniform enough to allow rigorous interpretation of the results. Expressing the data in terms of the shear stress and vertical effective stress on the horizontal plane is useful for engineering purposes. Some effective stress parameters that could be derived from a cyclic direct simple shear test shall not be confused with corresponding parameters derived from other shear tests having better defined states of stress (that is, cyclic triaxial tests).  
5.5 The values of settlement in saturated soil after cyclic loading can be assessed from the test results by allowing volume change at the end of the shearing to achieve same vertical effective stresses as at end of primary consolidation.  
5.6 The data from the consolidation portion of this test are comparable to results obtained using Test Method D2435/D2435M provided that the more rigorous consolidation procedure of Test Method D2435/D2435M is followed.
SCOPE
1.1 This test method defines equipment specifications and testing procedures for the measurement of cyclic strength, number of cycles to liquefaction or cyclic properties (Modulus and Damping) of soils, after one-dimensional consolidation using a cyclic mode of loading.  
1.2 The cyclic shearing can be applied using load control or displacement control. It shall be the responsibility of the agency requesting this test to specify the magnitude and frequency of the cyclic loading. Other loading histories may be used if required by the agency requesting the testing.  
1.3 This test method is written specifically for devices that test cylindrical specimens enclosed in a wire-reinforced membrane or a soft membrane within a stack of rigid rings (this test method applies to Teflon coated rigid rings as well). Other types of shear devices are beyond the scope of this test method.  
1.4 This test method can be used for testing cohesionless free draining soils or fine grained soils. However, this test method may be followed when testing most soil types if care is taken to ensure that any special considerations required for such soils are accounted for.  
1.5 The shearing phase of this test is conducted under constant volume conditions. Since the lateral confinement system prevents radial specimen strains, the constant volume condition is accomplished by preventing specimen height change during shear. Shearing under constant volume can be performed on dry or saturated specimens. The constant volume condition is equivalent to the undrained condition for fully saturated specimens. Cyclic direct simple shear testing with truly undrained conditions (restricting pore water flow from and into the specimen) can be performed using some simple shear devices, but is beyond the scope of this standard.2  
1.6 The cyclic strength of a soil is determined based on the number of cycles required to reach a limiting double amplitude shear strain or a single amplitude shear strain, while liquefaction is more commonly defined as 100 % change in vertical stress ratio (ch...

SIGNIFICANCE AND USE
5.1 The initial shear modulus (Gmax) of a soil specimen under particular stress and time conditions is an important parameter in small-strain dynamic analyses such as those to predict soil behavior or soil-structure interaction during earthquakes, explosions, and machine or traffic vibrations. Gmax can be equally important for small-strain cyclic situations such as those caused by wind or wave loading. Small-strain Gmax is also vital for non-linear analyses of large strain situations, where the larger strain soil stiffness results could come from torsional shear tests, for example. Shear wave velocity and Gmax can be used to compare different soil specimens in a laboratory testing program, and also for comparing laboratory and field measurements of these parameters.  
5.2 Torsional resonant column tests (Test Method D4015) are often used to determine properties of a soil specimen at small shear strains up to and possibly slightly beyond 0.01%. Resonant column test results can include Gmax versus time, shear modulus versus strain, damping ratio versus time and damping ratio versus strain. Bender element tests can only provide the first of these, Gmax versus time. The strain level in bender element tests is small (constant Gmax strain levels), but the strain magnitude is not known and the strain is not constant along the shear wave travel path due to material and geometric damping. Bender elements can therefore not be used to evaluate shear modulus versus strain and do not provide information about damping ratio. However, bender elements can be incorporated in a variety of different laboratory testing devices, allowing the measurement of small-strain and large-strain stiffness on the same specimen at the particular conditions of the test and possibly eliminating the need for additional resonant column tests.  
Note 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipmen...
SCOPE
1.1 This test method covers the laboratory use of piezo-ceramic bender elements to determine the shear wave velocity in soil specimens. A shear wave is generated at one boundary of a soil specimen and then received at an opposite boundary. The shear wave travel time is measured, which over a known travel distance yields the shear wave velocity. From this shear wave velocity and the density of the soil specimen the initial shear modulus (Gmax) can be determined, which is the result of primary interest from bender element tests.  
1.2 This shear wave velocity determination involves very small strains and is non-destructive to a test specimen. As such, bender element shear wave velocity determinations can be made at any time and any number of times during a laboratory test.  
1.3 This test method describes the use of bender elements in a triaxial type test (for example, Test Methods D3999, D4767, D5311, or D7181), but a similar procedure may be used for other laboratory applications, like in Direct Simple Shear (Test Method D6528) or oedometer tests (for example, Test Methods D2435 and D4186). Shear wave velocity can also be determined in unconfined soil specimens held together by matrix suction.  
1.4 Shear wave velocity can be determined in different directions in a triaxial test, for example vertically and horizontally. Shear waves generated to determine shear wave velocity can also be polarized in different directions, for example a horizontally propagating shear wave with either vertical or horizontal polarization. This test method describes the use of bender elements mounted in the top platen and base pedestal of a triaxial test specimen to measure shear wave velocity in the vertical direction. With additional bender elements mounted on opposite sides of a triaxial specimen, a similar procedure may be used to determine horizontal shear wave velocity.  
1.5 A variety of different interpretation methods to evaluate ...

SIGNIFICANCE AND USE
5.1 The seismic downhole method provides a designer with information pertinent to the seismic wave velocities of the materials in question (1)3. The P-wave and S-wave velocities are directly related to the important geotechnical elastic constants of Poisson’s ratio, shear modulus, bulk modulus, and Young’s modulus. Accurate in-situ P-wave and S-wave velocity profiles are essential in geotechnical foundation designs. These parameters are used in both analyses of soil behavior under both static and dynamic loads where the elastic constants are input variables into the models defining the different states of deformations such as elastic, elasto-plastic, and failure. Another important use of estimated shear wave velocities in geotechnical design is in the liquefaction assessment of soils.  
5.2 A fundamental assumption inherent in the test methods is that a laterally homogeneous medium is being characterized. In a laterally homogeneous medium the source wave train trajectories adhere to Snell’s law of refraction. Another assumption inherent in the test methods is that the stratigraphic medium to be characterized can have transverse isotropy. Transverse isotropy is a particularly simple form of anisotropy because velocities only vary with vertical incidence angle and not with azimuth. By placing and actuating the seismic source at offsets rotated 90° in plan view, it may be possible to confirm that a more complex model is needed to evaluate the field data.  
5.3 In soft saturated soil, where the P-wave velocity of the soil is less than the P-wave velocity of water, which is about 1450 m/s [4750 ft/s], the P-wave velocity measurement will primarily be controlled by the P-wave velocity of water and a direct measurement of the soil P-wave velocity will not be possible.
Note 1: The quality of the results produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities. Agencies that meet the crit...
SCOPE
1.1 These test methods address compression (P) and shear (S) waves propagating in the downward direction in a nearly vertical plane. The seismic waves can be denoted as PV or PZ for a downward propagating compression wave and as SVH or SZX for downward propagating and horizontally polarized shear wave. The SVH or SZX is also referred to as an SH wave. These test methods are limited to the determination of the interval velocities from arrival times and relative arrival times of compression (P) waves and vertically (SV) and horizontally (SH) oriented shear (S) seismic waves which are generated near surface and travel down to an array of vertically installed seismic sensors. Two methods are discussed, which include using either one or two downhole sensors (receivers).  
1.2 Various applications of the data will be addressed and acceptable procedures and equipment, such as seismic sources, receivers, and recording systems will be discussed. Other items addressed include source-to-receiver spacing, drilling, casing, grouting, a procedure for borehole installation, and conducting actual borehole and seismic cone tests. Data reduction and interpretation is limited to the identification of various seismic wave types, apparent velocity relation to true velocity, example computations, use of Snell's law of refraction, and assumptions.  
1.3 There are several acceptable devices that can be used to generate a high-quality P or SV source wave or both and SH source waves. Several types of commercially available receivers and recording systems can also be used to conduct an acceptable downhole survey. Special consideration should be given to the types of receivers used and their configuration to provide an output that accurately reflects the input motion. These test methods primarily concern the actual test procedure, data interpretation, and specifications for equipment which will yield uniform test results.  
1.4 All recorded and ...

SIGNIFICANCE AND USE
5.1 The seismic downhole method provides a designer with information pertinent to the seismic wave velocities of the materials in question (1)3. The P-wave and S-wave velocities are directly related to the important geotechnical elastic constants of Poisson’s ratio, shear modulus, bulk modulus, and Young’s modulus. Accurate in-situ P-wave and S-wave velocity profiles are essential in geotechnical foundation designs. These parameters are used in both analyses of soil behavior under both static and dynamic loads where the elastic constants are input variables into the models defining the different states of deformations such as elastic, elasto-plastic, and failure. Another important use of estimated shear wave velocities in geotechnical design is in the liquefaction assessment of soils.  
5.2 A fundamental assumption inherent in the test methods is that a laterally homogeneous medium is being characterized. In a laterally homogeneous medium the source wave train trajectories adhere to Snell’s law of refraction. Another assumption inherent in the test methods is that the stratigraphic medium to be characterized can have transverse isotropy. Transverse isotropy is a particularly simple form of anisotropy because velocities only vary with vertical incidence angle and not with azimuth. By placing and actuating the seismic source at offsets rotated 90° in plan view, it may be possible to evaluate the transverse anisotropy of the medium.  
5.3 In soft saturated soil, where the P-wave velocity of the soil is less than the P-wave velocity of water, which is about 1450 m/s [4750 ft/s], the P-wave velocity measurement will be controlled by the P-wave velocity of water and a direct measurement of the soil P-wave velocity will not be possible.
Note 1: The quality of the results produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities. Agencies that meet the criteria of Practice D3740 are gener...
SCOPE
1.1 These test methods are limited to the determination of the interval velocities from arrival times and relative arrival times of compression (P) waves and vertically (SV) and horizontally (SH) oriented shear (S) seismic waves which are generated near surface and travel down to an array of vertically installed seismic sensors. Two methods are discussed, which include using either one or two downhole sensors (receivers).  
1.2 Various applications of the data will be addressed and acceptable procedures and equipment, such as seismic sources, receivers, and recording systems will be discussed. Other items addressed include source-to-receiver spacing, drilling, casing, grouting, a procedure for borehole installation, and conducting actual borehole and seismic cone tests. Data reduction and interpretation is limited to the identification of various seismic wave types, apparent velocity relation to true velocity, example computations, use of Snell's law of refraction, and assumptions.  
1.3 There are several acceptable devices that can be used to generate a high-quality P or SV source wave or both and SH source waves. Several types of commercially available receivers and recording systems can also be used to conduct an acceptable downhole survey. Special consideration should be given to the types of receivers used and their configuration to provide an output that accurately reflects the input motion. These test methods primarily concern the actual test procedure, data interpretation, and specifications for equipment which will yield uniform test results.  
1.4 All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026.  
1.4.1 The procedures used to specify how data are collected/recorded and calculated in these test methods are regarded as the industry standard. In addition, they are representative of the significant digits that should generally be re...

SIGNIFICANCE AND USE
5.1 The equivalent elastic shear modulus and damping capacity of a given soil, as measured by the resonant column technique herein described, depend upon the strain amplitude of vibration, the state of effective stress, and the void ratio of the soil, temperature, time, etc. Since the application and control of the static axial and lateral stresses and the void ratio are not prescribed in these methods, the applicability of the results to field conditions will depend on the degree to which the application and control of the static axial and lateral stresses and the void ratio, as well as other parameters such as soil structure, duplicate field conditions. The techniques used to simulate field conditions depend on many factors and it is up to the engineer to decide on which techniques apply to a given situation and soil type. The results of these tests are useful for calculations involving soil-structure interaction and seismic response of soil deposits.
Note 1: The quality of the results produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.
SCOPE
1.1 These test methods cover the determination of shear modulus and shear damping as a function of shear strain amplitude for solid cylindrical specimens of soil in intact and remolded conditions by vibration using resonant column devices. The vibration of the specimen may be superposed on a controlled static state of stress in the specimen. The vibration apparatus and specimen may be enclosed in a triaxial chamber and subjected to an all-around pressure and axial load. In addition, the specimen may be subjected to other controlled conditions (for example, pore-water pressure, degree of saturation, temperature). These test methods of modulus and damping determination are considered nondestructive when the shear strain amplitudes of vibration are less than 10–2 % (10–4 in./in.), and many measurements may be made on the same specimen and with various states of static stress.  
1.2 Two device configurations are covered by these test methods: Device Type 1 where a known torque is applied to the top of the specimen and the resulting rotational motion is measured at the top of the specimen, and Device Type 2 where an uncalibrated torque is applied to the top of the specimen and the torque transmitted through the specimen is measured by a torque transducer at the base of the specimen. For both devices, the torque is applied to the active end (usually top) of the specimen and the rotational motion also is measured at the active end of the specimen.  
1.3 These test methods are limited to the determination of the shear modulus and shear damping, the necessary vibration, and specimen preparation procedures related to the vibration, etc., and do not cover the application, measurement, or control of the axial and lateral static normal stresses. The latter procedures may be covered by, but are not limited to, Test Method D2850, D3999/D3999M, D4767, D5311/D5311M, or D7181.  
1.4 Significant Digits—All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026.  
1.4.1 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 o...

SIGNIFICANCE AND USE
5.1 The equivalent elastic shear modulus and damping capacity of a given soil, as measured by the resonant column technique herein described, depend upon the strain amplitude of vibration, the state of effective stress, and the void ratio of the soil, temperature, time, etc. Since the application and control of the static axial and lateral stresses and the void ratio are not prescribed in these methods, the applicability of the results to field conditions will depend on the degree to which the application and control of the static axial and lateral stresses and the void ratio, as well as other parameters such as soil structure, duplicate field conditions. The techniques used to simulate field conditions depend on many factors and it is up to the engineer to decide on which techniques apply to a given situation and soil type. The results of these tests are useful for calculations involving soil-structure interaction and seismic response of soil deposits.
Note 1: The quality of the results produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.
SCOPE
1.1 These test methods cover the determination of shear modulus and shear damping as a function of shear strain amplitude for solid cylindrical specimens of soil in intact and remolded conditions by vibration using resonant column devices. The vibration of the specimen may be superposed on a controlled static state of stress in the specimen. The vibration apparatus and specimen may be enclosed in a triaxial chamber and subjected to an all-around pressure and axial load. In addition, the specimen may be subjected to other controlled conditions (for example, pore-water pressure, degree of saturation, temperature). These test methods of modulus and damping determination are considered nondestructive when the shear strain amplitudes of vibration are less than 10–2 % (10–4 in./in.), and many measurements may be made on the same specimen and with various states of static stress.  
1.2 Two device configurations are covered by these test methods: Device Type 1 where a known torque is applied to the top of the specimen and the resulting rotational motion is measured at the top of the specimen, and Device Type 2 where an uncalibrated torque is applied to the top of the specimen and the torque transmitted through the specimen is measured by a torque transducer at the base of the specimen. For both devices, the torque is applied to the active end (usually top) of the specimen and the rotational motion also is measured at the active end of the specimen.  
1.3 These test methods are limited to the determination of the shear modulus and shear damping, the necessary vibration, and specimen preparation procedures related to the vibration, etc., and do not cover the application, measurement, or control of the axial and lateral static normal stresses. The latter procedures may be covered by, but are not limited to, Test Method D2850, D3999/D3999M, D4767, D5311/D5311M, or D7181.  
1.4 Significant Digits—All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026.  
1.4.1 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 o...

SIGNIFICANCE AND USE
5.1 The seismic downhole method provides a designer with information pertinent to the seismic wave velocities of the materials in question (1). The P-wave and S-wave velocities are directly related to the important geotechnical elastic constants of Poisson’s ratio, shear modulus, bulk modulus, and Young’s modulus. Accurate in-situ P-wave and S-wave velocity profiles are essential in geotechnical foundation designs. These parameters are used in both analyses of soil behavior under both static and dynamic loads where the elastic constants are input variables into the models defining the different states of deformations such as elastic, elasto-plastic, and failure. Another important use of estimated shear wave velocities in geotechnical design is in the liquefaction assessment of soils.  
5.2 A fundamental assumption inherent in the test methods is that a laterally homogeneous medium is being characterized. In a laterally homogeneous medium the source wave train trajectories adhere to Snell’s law of refraction. Another assumption inherent in the test methods is that the stratigraphic medium to be characterized can have transverse isotropy. Transverse isotropy is a particularly simple form of anisotropy because velocities only vary with vertical incidence angle and not with azimuth. By placing and actuating the seismic source at offsets rotated 90° in plan view, it may be possible to evaluate the transverse anisotropy of the medium.
Note 1: The quality of the results produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factor...
SCOPE
1.1 These test methods are limited to the determination of the interval velocities from arrival times and relative arrival times of compression (P) and vertically (SV) and horizontally (SH) polarized shear (S) seismic waves which are generated near surface and travel down to an array of vertically installed seismic sensors. A preferred method intended to obtain data for use on critical projects where the highest quality data is required is included. Also included is an optional method intended for use on projects which do not require measurements of a high degree of precision.  
1.2 Various applications of the data will be addressed and acceptable procedures and equipment, such as seismic sources, receivers, and recording systems will be discussed. Other items addressed include source-to-receiver spacing, drilling, casing, grouting, a procedure for borehole installation, and conducting actual borehole and seismic cone tests. Data reduction and interpretation is limited to the identification of various seismic wave types, apparent velocity relation to true velocity, example computations, use of Snell's law of refraction, and assumptions.  
1.3 There are several acceptable devices that can be used to generate a high-quality P or SV source wave or both and SH source waves. Several types of commercially available receivers and recording systems can also be used to conduct an acceptable downhole survey. Special consideration should be given to the types of receivers used and their configuration. Heavily-damped sensors should not be used so that spectral smearing, phase shifting, and latency response between sensors is avoided. These test methods primarily concern the actual test procedure, data interpretation, and specifications for equipment which will yield uniform test results.  
1.4 All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026.  
1.4.1 ...

SIGNIFICANCE AND USE
Cyclic triaxial strength test results are used for evaluating the ability of a soil to resist the shear stresses induced in a soil mass due to earthquake or other cyclic loading.
Cyclic triaxial strength tests may be performed at different values of effective confining pressure on isotropically consolidated specimens to provide data required for estimating the cyclic stability of a soil.
Cyclic triaxial strength tests may be performed at a single effective confining pressure, usually equal to 100 kN/m2 (14.5 lb/in.2), or alternate pressures as appropriate on isotropically consolidated specimens to compare cyclic strength results for a particular soil type with that of other soils, Ref (2).
The cyclic triaxial test is a commonly used technique for determining cyclic soil strength.
Cyclic strength depends upon many factors, including density, confining pressure, applied cyclic shear stress, stress history, grain structure, age of soil deposit, specimen preparation procedure, and the frequency, uniformity, and shape of the cyclic wave form. Thus, close attention must be given to testing details and equipment.
There are certain limitations inherent in using cyclic triaxial tests to simulate the stress and strain conditions of a soil element in the field during an earthquake.
Nonuniform stress conditions within the test specimen are imposed by the specimen end platens. This can cause a redistribution of void ratio within the specimen during the test.
A 90° change in the direction of the major principal stress occurs during the two halves of the loading cycle on isotropically consolidated specimens.
The maximum cyclic shear stress that can be applied to the specimen is controlled by the stress conditions at the end of consolidation and the pore-water pressures generated during testing. For an isotropically consolidated contractive (volume decreasing) specimen tested in cyclic compression, the maximum cyclic shear stress that can be applied to the specimen ...
SCOPE
1.1 This test method covers the determination of the cyclic strength (sometimes called the liquefaction potential) of saturated soils in either intact or reconstituted states by the load-controlled cyclic triaxial technique.
1.2 The cyclic strength of a soil is evaluated relative to a number of factors, including: the development of axial strain, magnitude of applied cyclic stress, number of cycles of stress application, development of excess pore-water pressure, and state of effective stress. A comprehensive review of factors affecting cyclic triaxial test results is contained in the literature (1).  
1.3 Cyclic triaxial strength tests are conducted under undrained conditions to simulate essentially undrained field conditions during earthquake or other cyclic loading.
1.4 Cyclic triaxial strength tests are destructive. Failure may be defined on the basis of the number of stress cycles required to reach a limiting strain or 100 % pore pressure ratio. See Section 3 for Terminology.
1.5 This test method is generally applicable for testing cohesionless free draining soils of relatively high permeability. When testing well-graded materials, silts, or clays, pore-water pressures monitored at the specimen ends may not represent pore-water pressure values throughout the specimen. However, this test method may be followed when testing most soil types if care is taken to ensure that problem soils receive special consideration when tested and when test results are evaluated.
1.6 The values stated in either SI units or inch-pound units [presented in brackets] are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method. ...

SIGNIFICANCE AND USE
The cyclic triaxial test permits determination of the secant modulus and damping coefficient for cyclic axial loading of a prismatic soil specimen in hydrostatically consolidated, undrained conditions. The secant modulus and damping coefficient from this test may be different from those obtained from a torsional shear type of test on the same material.  
The secant modulus and damping coefficient are important parameters used in dynamic, performance evaluation of both natural and engineered structures under dynamic or cyclic loads such as caused by earthquakes, ocean wave, or blasts. These parameters can be used in dynamic response analyses including, finite elements, finite difference, and linear or non-linear analytical methods.
Note 1—The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.
SCOPE
1.1 These test methods cover the determination of the modulus and damping properties of soils in either intact or reconstituted states by either load or stroke controlled cyclic triaxial techniques. The standard is focused on determining these properties for soils in hydrostatically consolidated, undrained conditions.
1.2 The cyclic triaxial properties of initially saturated or unsaturated soil specimens are evaluated relative to a number of factors including: strain level, density, number of cycles, material type, and effective stress.
1.3 These test methods are applicable to both fine-grained and coarse-grained soils as defined by the unified soil classification system or by Classification D2487. Test specimens may be intact or reconstituted by compaction in the laboratory.
1.4 Two test methods are provided for using a cyclic loader to determine the secant Young's modulus (E) and damping coefficient (D) for a soil specimen. The first test method (A) permits the determination of E and D using a constant load apparatus. The second test method (B) permits the determination of E and D using a constant stroke apparatus. The test methods are as follows:
1.4.1 Test Method A—This test method requires the application of a constant cyclic load to the test specimen. It is used for determining the secant Young's modulus and damping coefficient under a constant load condition.
1.4.2 Test Method B—This test method requires the application of a constant cyclic deformation to the test specimen. It is used for determining the secant Young's modulus and damping coefficient under a constant stroke condition.
1.5 The development of relationships to aid in interpreting and evaluating test results are left to the engineer or office requesting the test.
1.6 Limitations—There are certain limitations inherent in using cyclic triaxial tests to simulate the stress and strain conditions of a soil element in the field during an earthquake, with several summarized in the following sections. With due consideration for the factors affecting test results, carefully conducted cyclic triaxial tests can provide data on the cyclic behavior of soils with a degree of accuracy adequate for meaningful evaluations of modulus and damping coefficient below a shearing strain level of 0.5 %.
1.6.1 Nonuniform stress conditions within the test specimen are imposed by the specimen end platens.
1.6.2 A 90° change in the direction of the major principal stress occurs during the two halves of the loading cycle on isotropically confined specimens.
1.6.3 The maximum cyclic axial stress that can be applied to a saturated specimen is controlled by t...

SIGNIFICANCE AND USE
The seismic downhole method provides a designer with information pertinent to the seismic wave velocities of the materials in question (1). The P-wave and S-wave velocities are directly related to the important geotechnical elastic constants of Poisson’s ratio, shear modulus, bulk modulus, and Young’s modulus. Accurate in-situ P-wave and S-wave velocity profiles are essential in geotechnical foundation designs. These parameters are used in both analyses of soil behavior under both static and dynamic loads where the elastic constants are input variables into the models defining the different states of deformations such as elastic, elasto-plastic, and failure. Another important use of estimated shear wave velocities in geotechnical design is in the liquefaction assessment of soils.
A fundamental assumption inherent in the test methods is that a laterally homogeneous medium is being characterized. In a laterally homogeneous medium the source wave train trajectories adhere to Snell’s law of refraction. Another assumption inherent in the test methods is that the stratigraphic medium to be characterized can have transverse isotropy. Transverse isotropy is a particularly simple form of anisotropy because velocities only vary with vertical incidence angle and not with azimuth. By placing and actuating the seismic source at offsets rotated 90° in plan view, it may be possible to evaluate the transverse anisotropy of the medium.
Note 1—The quality of the results produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities. Agencies that meet the criteria of Practice D 3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D 3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D 3740 provides a means of evaluating some of those factors.
SCOPE
1.1 These test methods are limited to the determination of the interval velocities from arrival times and relative arrival times of compression (P) and vertically (SV) and horizontally (SH) polarized shear (S) seismic waves which are generated near surface and travel down to an array of vertically installed seismic sensors. A preferred method intended to obtain data for use on critical projects where the highest quality data is required is included. Also included is an optional method intended for use on projects which do not require measurements of a high degree of precision.
1.2 Various applications of the data will be addressed and acceptable procedures and equipment, such as seismic sources, receivers, and recording systems will be discussed. Other items addressed include source-to-receiver spacing, drilling, casing, grouting, a procedure for borehole installation, and conducting actual borehole and seismic cone tests. Data reduction and interpretation is limited to the identification of various seismic wave types, apparent velocity relation to true velocity, example computations, use of Snell's law of refraction, and assumptions.
1.3 There are several acceptable devices that can be used to generate a high-quality P or SV source wave or both and SH source waves. Several types of commercially available receivers and recording systems can also be used to conduct an acceptable downhole survey. Special consideration should be given to the types of receivers used and their configuration. Heavily-damped sensors should not be used so that spectral smearing, phase shifting, and latency response between sensors is avoided. These test methods primarily concern the actual test procedure, data interpretation, and specifications for equipment which will yield uniform test results.
1.4 All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D 6026.
1.4.1 The proced...

SIGNIFICANCE AND USE
The seismic downhole method provides a designer with information pertinent to the seismic wave velocities of the materials in question (1). The P-wave and S-wave velocities are directly related to the important geotechnical elastic constants of Poisson’s ratio, shear modulus, bulk modulus, and Young’s modulus. Accurate in-situ P-wave and S-wave velocity profiles are essential in geotechnical foundation designs. These parameters are used in both analyses of soil behavior under both static and dynamic loads where the elastic constants are input variables into the models defining the different states of deformations such as elastic, elasto-plastic, and failure. Another important use of estimated shear wave velocities in geotechnical design is in the liquefaction assessment of soils.
A fundamental assumption inherent in the test methods is that a laterally homogeneous medium is being characterized. In a laterally homogeneous medium the source wave train trajectories adhere to Snell’s law of refraction and Fermat’s principle of least time. Another assumption inherent in the test methods is that the stratigraphic medium to be characterized can have transverse isotropy. Transverse isotropy is a particularly simple form of anisotropy because velocities only vary with vertical incidence angle and not with azimuth.
Note 1—The quality of the results produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities. Agencies that meet the criteria of Practice D 3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D 3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D 3740 provides a means of evaluating some of those factors.
SCOPE
1.1 These test methods are limited to the determination of the interval velocities from arrival times and relative arrival times of compression (P) and vertically (SV) and horizontally (SH) polarized shear (S) seismic waves which are generated near surface and travel down to an array of vertically installed seismic sensors. A preferred method intended to obtain data for use on critical projects where the highest quality data is required is included. Also included is an optional method intended for use on projects which do not require measurements of a high degree of precision.
1.2 Various applications of the data will be addressed and acceptable procedures and equipment, such as seismic sources, receivers, and recording systems will be discussed. Other items addressed include source-to-receiver spacing, drilling, casing, grouting, a procedure for borehole installation, and borehole and seismic cone actual test conduct. Data reduction and interpretation is limited to the identification of various seismic wave types, apparent velocity relation to true velocity, example computations, use of Snell's law of refraction, and assumptions.
1.3 There are several acceptable devices that can be used to generate a high-quality P or SV source wave or both and SH source waves. Several types of commercially available receivers and recording systems can also be used to conduct an acceptable downhole survey. Special consideration should be given to the types of receivers used and their configuration. Heavily-damped sensors should not be used so that spectral smearing, phase shifting, and latency response between sensors is avoided. These test methods primarily concern the actual test procedure, data interpretation, and specifications for equipment which will yield uniform test results.
1.4 All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D 6026.
1.4.1 The procedures used to specify how data are collected/recorded and calculated in these test methods are regarded as the industry stand...

SIGNIFICANCE AND USE
The modulus and damping of a given soil, as measured by the resonant-column technique herein described, depend upon the strain amplitude of vibration, the ambient state of effective stress, and the void ratio of the soil, temperature, time, etc. Since the application and control of the ambient stresses and the void ratio are not prescribed in these methods, the applicability of the results to field conditions will depend on the degree to which the application and control of the ambient stresses and the void ratio, as well as other parameters such as soil structure, duplicate field conditions. The techniques used to simulate field conditions depend on many factors and it is up to the engineer to decide on which techniques apply to a given situation and soil type.
SCOPE
1.1 These test methods cover the determination of shear modulus, shear damping, rod modulus (commonly referred to as Young's modulus), and rod damping for solid cylindrical specimens of soil in the undisturbed and remolded conditions by vibration using the resonant column. The vibration of the specimen may be superposed on a controlled ambient state of stress in the specimen. The vibration apparatus and specimen may be enclosed in a triaxial chamber and subjected to an all-around pressure and axial load. In addition, the specimen may be subjected to other controlled conditions (for example, pore-water pressure, degree of saturation, temperature). These test methods of modulus and damping determination are considered nondestructive when the strain amplitudes of vibration are less than 104 rad (104 in./in.), and many measurements may be made on the same specimen and with various states of ambient stress.
1.2 These test methods cover only the determination of the modulus and damping, the necessary vibration, and specimen preparation procedures related to the vibration, etc., and do not cover the application, measurement, or control of the ambient stress. The latter procedures may be covered by, but are not limited to, Test Methods D 2166 or D 2850.
1.3 All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D 6026.
1.3.1 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 users 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.
1.3.2 Measurements made to more significant digits or better sensitivity than specified in this standard shall not be regarded a nonconformance with this standard.
1.4 The values stated in SI units are to be regarded as the standard. Reporting test results in units other than SI shall be regarded as conformance with these test methods.
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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
The seismic crosshole method provides a designer with information pertinent to the seismic wave velocities of the materials in question (1).2 This data may be used as input into static/dynamic analyses, as a means for computing shear modulus, Young’modulus, and Poisson’ratio, or simply for the determination of anomalies that might exist between boreholes.
Fundamental assumptions inherent in the test methods are as follows:
5.2.1 Horizontal layering is assumed.
5.2.2 Snell’laws of refraction will apply. If Snell’laws of refraction are not applied, velocities obtained will be unreliable.
SCOPE
1.1 These test methods are limited to the determination of horizontally traveling compression (P) and shear (S) seismic waves at test sites consisting primarily of soil materials (as opposed to rock). A preferred test method intended for use on critical projects where the highest quality data must be obtained is included. Also included is an optional method intended for use on projects which do not require measurements of a high degree of precision.
1.2 Various applications of the data will be addressed and acceptable interpretation procedures and equipment, such as seismic sources, receivers, and recording systems will be discussed. Other items addressed include borehole spacing, drilling, casing, grouting, deviation surveys, and actual test conduct. Data reduction and interpretation is limited to the identification of various seismic wave types, apparent velocity relation to true velocity, example computations, effective borehole spacing, use of Snell's law of refraction, assumptions, and computer programs.
1.3 It is important to note that more than one acceptable device can be used to generate a high-quality P wave or S wave, or both. Further, several types of commercially available receivers and recording systems can also be used to conduct an acceptable crosshole survey. Consequently, these test methods primarily concern the actual test procedure, data interpretation, and specifications for equipment which will yield uniform test results.
1.4 All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D 6026.
1.4.1 The procedures used to specify how data are collected/recorded and calculated in these test methods 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 users 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 these test methods to consider significant digits used in analysis methods for engineering design.
1.4.2 Measurements made to more significant digits or better sensitivity than specified in these test methods shall not be regarded a nonconformance with this standard.
1.5 These test methods are written using SI units. Inch-pound units are provided for convenience. The values stated in inch pound units may not be exact equivalents; therefore, they shall be used independently of the SI system. Combining values from the two systems may result in nonconformance with these test methods.
1.5.1 The gravitational system of inch-pound units is used when dealing with inch-pound units. In this system, the pound (lbf) represents a 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.
1.5.2 It is common practice in the engineering/construction profession to concurrently use pounds to represent both a unit of mass (lbm) and of force (lbf). This implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. It is scientifically undesirable to com...

SIGNIFICANCE AND USE
Cyclic triaxial strength test results are used for evaluating the ability of a soil to resist the shear stresses induced in a soil mass due to earthquake or other cyclic loading.
Cyclic triaxial strength tests may be performed at different values of effective confining pressure on isotropically consolidated specimens to provide data required for estimating the cyclic stability of a soil.
Cyclic triaxial strength tests may be performed at a single effective confining pressure, usually equal to 14.5 lb/in. 2(100 kN/m2), or alternate pressures as appropriate on isotropically consolidated specimens to compare cyclic strength results for a particular soil type with that of other soils, Ref (2).
The cyclic triaxial test is a commonly used technique for determining cyclic soil strength.
Cyclic strength depends upon many factors, including density, confining pressure, applied cyclic shear stress, stress history, grain structure, age of soil deposit, specimen preparation procedure, and the frequency, uniformity, and shape of the cyclic wave form. Thus, close attention must be given to testing details and equipment.
SCOPE
1.1 This test method covers the determination of the cyclic strength (sometimes called the liquefaction potential) of saturated soils in either undisturbed or reconstituted states by the load-controlled cyclic triaxial technique.
1.2 The cyclic strength of a soil is evaluated relative to a number of factors, including: the development of axial strain, magnitude of applied cyclic stress, number of cycles of stress application, development of excess pore-water pressure, and state of effective stress. A comprehensive review of factors affecting cyclic triaxial test results is contained in the literature (1).  
1.3 Cyclic triaxial strength tests are conducted under undrained conditions to simulate essentially undrained field conditions during earthquake or other cyclic loading.
1.4 Cyclic triaxial strength tests are destructive. Failure may be defined on the basis of the number of stress cycles required to reach a limiting strain or 100 % pore pressure ratio. See Section 3 for Terminology.
1.5 This test method is generally applicable for testing cohesionless free draining soils of relatively high permeability. When testing well-graded materials, silts, or clays, it should be recognized that pore-water pressures monitored at the specimen ends to not in general represent pore-water pressure values throughout the specimen. However, this test method may be followed when testing most soil types if care is taken to ensure that problem soils receive special consideration when tested and when test results are evaluated.
1.6 There are certain limitations inherent in using cyclic triaxial tests to simulate the stress and strain conditions of a soil element in the field during an earthquake.
1.6.1 Nonuniform stress conditions within the test specimen are imposed by the specimen end platens. This can cause a redistribution of void ratio within the specimen during the test.
1.6.2 A 90° change in the direction of the major principal stress occurs during the two halves of the loading cycle on isotropically consolidated specimens.
1.6.3 The maximum cyclic shear stress that can be applied to the specimen is controlled by the stress conditions at the end of consolidation and the pore-water pressures generated during testing. For an isotropically consolidated contractive (volume decreasing) specimen tested in cyclic compression, the maximum cyclic shear stress that can be applied to the specimen is equal to one-half of the initial total axial pressure. Since cohesionless soils are not capable of taking tension, cyclic shear stresses greater than this value tend to lift the top platen from the soil specimen. Also, as the pore-water pressure increases during tests performed on isotropically consolidated specimens, the effective confining pressure is reduced, contributing to the tendenc...

SCOPE
1.1 These test methods are limited to the determination of horizontally traveling compression (P) and shear (S) seismic waves at test sites consisting primarily of soil materials (as opposed to rock). A preferred test method intended for use on critical projects where the highest quality data must be obtained is included. Also included is an optional method intended for use on projects which do not require measurements of a high degree of precision.
1.2 Various applications of the data will be addressed and acceptable interpretation procedures and equipment, such as seismic sources, receivers, and recording systems will be discussed. Other items addressed include borehole spacing, drilling, casing, grouting, deviation surveys, and actual test conduct. Data reduction and interpretation is limited to the identification of various seismic wave types, apparent velocity relation to true velocity, example computations, effective borehole spacing, use of Snell's law of refraction, assumptions, and computer programs.
1.3 It is important to note that more than one acceptable device can be used to generate a high-quality P wave or S wave, or both. Further, several types of commercially available receivers and recording systems can also be used to conduct an acceptable crosshole survey. Consequently, these test methods primarily concern the actual test procedure, data interpretation, and specifications for equipment which will yield uniform test results.
1.4 The values stated in either SI units or inch-pound units are to be regarded as standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other.
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 and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 These test methods cover the determination of shear modulus, shear damping, rod modulus (commonly referred to as Young's modulus), and rod damping for solid cylindrical specimens of soil in the undisturbed and remolded conditions by vibration using the resonant column. The vibration of the specimen may be superposed on a controlled ambient state of stress in the specimen. The vibration apparatus and specimen may be enclosed in a triaxial chamber and subjected to an all-around pressure and axial load. In addition, the specimen may be subjected to other controlled conditions (for example, pore-water pressure, degree of saturation, temperature). These test methods of modulus and damping determination are considered nondestructive when the strain amplitudes of vibration are less than 10-4 rad (10-4 in./in.), and many measurements may be made on the same specimen and with various states of ambient stress.
1.2 These test methods cover only the determination of the modulus and damping, the necessary vibration, and specimen preparation procedures related to the vibration, etc., and do not cover the application, measurement, or control of the ambient stress. The latter procedures may be covered by, but are not limited to, Test Methods D2166 or D2850.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the determination of the cyclic strength (sometimes called the liquefaction potential) of saturated soils in either undisturbed or reconstituted states by the load-controlled cyclic triaxial technique.
1.2 The cyclic strength of a soil is evaluated relative to a number of factors, including: the development of axial strain, magnitude of applied cyclic stress, number of cycles of stress application, development of excess pore-water pressure, and state of effective stress. A comprehensive review of factors affecting cyclic triaxial test results is contained in the literature (1).  
1.3 Cyclic triaxial strength tests are conducted under undrained conditions to simulate essentially undrained field conditions during earthquake or other cyclic loading.
1.4 Cyclic triaxial strength tests are destructive. Failure may be defined on the basis of the number of stress cycles required to reach a limiting strain or 100% pore pressure ratio. See Section 3 for Terminology.
1.5 This test method is generally applicable for testing cohesionless free draining soils of relatively high permeability. When testing well-graded materials, silts, or clays, it should be recognized that pore-water pressures monitored at the specimen ends to not in general represent pore-water pressure values throughout the specimen. However, this test method may be followed when testing most soil types if care is taken to ensure that problem soils receive special consideration when tested and when test results are evaluated.
1.6 There are certain limitations inherent in using cyclic triaxial tests to simulate the stress and strain conditions of a soil element in the field during an earthquake.
1.6.1 Nonuniform stress conditions within the test specimen are imposed by the specimen end platens. This can cause a redistribution of void ratio within the specimen during the test.
1.6.2 A 90° change in the direction of the major principal stress occurs during the two halves of the loading cycle on isotropically consolidated specimens.
1.6.3 The maximum cyclic shear stress that can be applied to the specimen is controlled by the stress conditions at the end of consolidation and the pore-water pressures generated during testing. For an isotropically consolidated contractive (volume decreasing) specimen tested in cyclic compression, the maximum cyclic shear stress that can be applied to the specimen is equal to one-half of the initial total axial pressure. Since cohesionless soils are not capable of taking tension, cyclic shear stresses greater than this value tend to lift the top platen from the soil specimen. Also, as the pore-water pressure increases during tests performed on isotropically consolidated specimens, the effective confining pressure is reduced, contributing to the tendency of the specimen to neck during the extension portion of the load cycle, invalidating test results beyond that point.
1.6.4 While it is advised that the best possible undisturbed specimens be obtained for cyclic strength testing, it is sometimes necessary to reconstitute soil specimens. It has been shown that different methods of reconstituting specimens to the same density may result in significantly different cyclic strengths. Also, undisturbed specimens will almost always be stronger than reconstituted specimens.
1.6.5 The interaction between the specimen, membrane, and confining fluid has an influence on cyclic behavior. Membrane compliance effects cannot be readily accounted for in the test procedure or in interpretation of test results. Changes in pore-water pressure can cause changes in membrane penetration in specimens of cohesionless soils. These changes can significantly influence the test results.
1.6.6 The mean total confining pressure is asymmetric during the compression and extension stress application when the chamber pressure is constant. This is totally different from the symmetric stress in the simple shear case...

SCOPE
1.1 These test methods cover the determination of the modulus and damping properties of soils in either undisturbed or reconstituted states by either load or stroke controlled cyclic triaxial techniques.  
1.2 The cyclic triaxial properties of soil are evaluated relative to a number of factors including: strain level, density, number of cycles, material type, saturation, and effective stress.  
1.3 These test methods are applicable to both fine-grained and coarse-grained soils as defined by the unified soil classification system or by Classification D2487. Test specimens may be undisturbed or reconstituted by compaction in the laboratory.  
1.4 Two test methods are provided for using a cyclic loader to determine Young's modulus (E) and damping (D) properties. The first test method (A) permits the determination of E and D using a constant load apparatus. The second test method (B) permits the determination of E and D using a constant stroke apparatus. The test methods are as follows:  
1.4.1 Test Method A -This test method requires the application of a constant cyclic load to the test specimen. It is used for determining the Young's modulus and damping under a constant load condition.  
1.4.2 Test Method B -This test method requires the application of a constant cyclic deformation to the test specimen. It is used for determining the Young's modulus and damping under a constant stroke condition.  
1.5 The development of relationships to aid in interpreting and evaluating test results are left to the engineer or office requesting the test.  
1.6 Limitations -There are certain limitations inherent in using cyclic triaxial tests to simulate the stress and strain conditions of a soil element in the field during an earthquake.  
1.6.1 Nonuniform stress conditions within the test specimen are imposed by the specimen end platens.  
1.6.2 A 90° change in the direction of the major principal stress occurs during the two halves of the loading cycle on isotropically confined specimens and at certain levels of cyclic stress application on anisotropically confined specimens.  
1.6.3 The maximum cyclic axial stress that can be applied to a saturated specimen is controlled by the stress conditions at the end of confining stress application and the pore-water pressures generated during testing. For an isotropically confined specimen tested in cyclic compression, the maximum cyclic axial stress that can be applied to the specimen is equal to the effective confining pressure. Since cohesionless soils are not capable of taking tension, cyclic axial stresses greater than this value tend to lift the top platen from the soil specimen. Also, as the pore-water pressure increases during tests performed on isotropically confined specimens, the effective confining pressure is reduced, contributing to the tendency of the specimen to neck during the extension portion of the load cycle, invalidating test results beyond that point.  
1.6.4 While it is advised that the best possible undisturbed specimens be obtained for cyclic testing, it is sometimes necessary to reconstitute soil specimens. It has been shown that different methods of reconstituting specimens to the same density may result in significantly different cyclic behavior. Also, undisturbed specimens will almost always be stronger than reconstituted specimens of the same density.  
1.6.5 The interaction between the specimen, membrane, and confining fluid has an influence on cyclic behavior. Membrane compliance effects cannot be readily accounted for in the test procedure or in interpretation of test results. Changes in pore-water pressure can cause changes in membrane penetration in specimens of cohesionless soils. These changes can significantly influence the test results.  
1.6.6 Despite these limitations, with due consideration for the factors affecting test results, carefully conducted cyclic triaxial tests can provide data on the cyclic behavior of soils with a...

SIGNIFICANCE AND USE
Cyclic triaxial strength test results are used for evaluating the ability of a soil to resist the shear stresses induced in a soil mass due to earthquake or other cyclic loading.
5.1.1 Cyclic triaxial strength tests may be performed at different values of effective confining pressure on isotropically consolidated specimens to provide data required for estimating the cyclic stability of a soil.
5.1.2 Cyclic triaxial strength tests may be performed at a single effective confining pressure, usually equal to 14.5 lb/in. 2(100 kN/m2), or alternate pressures as appropriate on isotropically consolidated specimens to compare cyclic strength results for a particular soil type with that of other soils, Ref (2).
The cyclic triaxial test is a commonly used technique for determining cyclic soil strength.
Cyclic strength depends upon many factors, including density, confining pressure, applied cyclic shear stress, stress history, grain structure, age of soil deposit, specimen preparation procedure, and the frequency, uniformity, and shape of the cyclic wave form. Thus, close attention must be given to testing details and equipment.
SCOPE
1.1 This test method covers the determination of the cyclic strength (sometimes called the liquefaction potential) of saturated soils in either undisturbed or reconstituted states by the load-controlled cyclic triaxial technique.
1.2 The cyclic strength of a soil is evaluated relative to a number of factors, including: the development of axial strain, magnitude of applied cyclic stress, number of cycles of stress application, development of excess pore-water pressure, and state of effective stress. A comprehensive review of factors affecting cyclic triaxial test results is contained in the literature ().
1.3 Cyclic triaxial strength tests are conducted under undrained conditions to simulate essentially undrained field conditions during earthquake or other cyclic loading.
1.4 Cyclic triaxial strength tests are destructive. Failure may be defined on the basis of the number of stress cycles required to reach a limiting strain or 100 % pore pressure ratio. See Section for Terminology.
1.5 This test method is generally applicable for testing cohesionless free draining soils of relatively high permeability. When testing well-graded materials, silts, or clays, it should be recognized that pore-water pressures monitored at the specimen ends to not in general represent pore-water pressure values throughout the specimen. However, this test method may be followed when testing most soil types if care is taken to ensure that problem soils receive special consideration when tested and when test results are evaluated.
1.6 There are certain limitations inherent in using cyclic triaxial tests to simulate the stress and strain conditions of a soil element in the field during an earthquake.
1.6.1 Nonuniform stress conditions within the test specimen are imposed by the specimen end platens. This can cause a redistribution of void ratio within the specimen during the test.
1.6.2 A 90 change in the direction of the major principal stress occurs during the two halves of the loading cycle on isotropically consolidated specimens.
1.6.3 The maximum cyclic shear stress that can be applied to the specimen is controlled by the stress conditions at the end of consolidation and the pore-water pressures generated during testing. For an isotropically consolidated contractive (volume decreasing) specimen tested in cyclic compression, the maximum cyclic shear stress that can be applied to the specimen is equal to one-half of the initial total axial pressure. Since cohesionless soils are not capable of taking tension, cyclic shear stresses greater than this value tend to lift the top platen from the soil specimen. Also, as the pore-water pressure increases during tests performed on isotropically consolidated specimens, the effective confining pressure is reduced, contributing to the tendency...

SIGNIFICANCE AND USE
The cyclic triaxial modulus and damping test provides parameters that may be considered for use in dynamic, linear and non-linear analytical methods. These test methods are used for the performance evaluation of both natural and engineered structures under dynamic of cyclic loads such as caused by earthquakes, ocean wave, or blast.
One of the primary purposes of these test methods is to obtain data that are used to calculate Young’modulus.
Note 1—The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D 3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D 3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D 3740 provides a means of evaluating some of those factors.
SCOPE
1.1 These test methods cover the determination of the modulus and damping properties of soils in either undisturbed or reconstituted states by either load or stroke controlled cyclic triaxial techniques.
1.2 The cyclic triaxial properties of soil are evaluated relative to a number of factors including: strain level, density, number of cycles, material type, saturation, and effective stress.
1.3 These test methods are applicable to both fine-grained and coarse-grained soils as defined by the unified soil classification system or by Classification D 2487. Test specimens may be undisturbed or reconstituted by compaction in the laboratory.
1.4 Two test methods are provided for using a cyclic loader to determine Young's modulus (E) and damping (D) properties. The first test method (A) permits the determination of E and D using a constant load apparatus. The second test method (B) permits the determination of E and D using a constant stroke apparatus. The test methods are as follows:
1.4.1 Test Method AThis test method requires the application of a constant cyclic load to the test specimen. It is used for determining the Young's modulus and damping under a constant load condition.
1.4.2 Test Method BThis test method requires the application of a constant cyclic deformation to the test specimen. It is used for determining the Young's modulus and damping under a constant stroke condition.
1.5 The development of relationships to aid in interpreting and evaluating test results are left to the engineer or office requesting the test.
1.6 LimitationsThere are certain limitations inherent in using cyclic triaxial tests to simulate the stress and strain conditions of a soil element in the field during an earthquake.
1.6.1 Nonuniform stress conditions within the test specimen are imposed by the specimen end platens.
1.6.2 A 90 change in the direction of the major principal stress occurs during the two halves of the loading cycle on isotropically confined specimens and at certain levels of cyclic stress application on anisotropically confined specimens.
1.6.3 The maximum cyclic axial stress that can be applied to a saturated specimen is controlled by the stress conditions at the end of confining stress application and the pore-water pressures generated during testing. For an isotropically confined specimen tested in cyclic compression, the maximum cyclic axial stress that can be applied to the specimen is equal to the effective confining pressure. Since cohesionless soils are not capable of taking tension, cyclic axial stresses greater than this value tend to lift the top platen from the soil specimen. Also, as the pore-water pressure increases during tests performed on isotropically confined specimens, the effective confining pressure is reduced, contributing to the tendency of the specimen to neck during the extension portion of the load cycle, invalidating test results beyond that point.
1.6.4 While it is ...

SIGNIFICANCE AND USE
5.1 The seismic crosshole method provides a designer with information pertinent to the seismic wave velocities of the materials in question (1).2 This data may be used as follows:  
5.1.1 For input into static/dynamic analyses;  
5.1.2 For computing shear modulus, Young's modulus, and Poisson's ratio (provided density is known or assumed);  
5.1.3 For determining Seismic Site Class using the appropriate Building Code; and  
5.1.4 For assessing liquefaction potential.  
5.2 Fundamental assumptions inherent in the test methods are as follows:  
5.2.1 Horizontal layering is assumed.  
5.2.2 Snell’s law of refraction applies to P-waves and S-waves and to the velocities derived from crosshole tests. If Snell’s law of refraction is not considered in the analysis of Crosshole seismic testing data, the report shall so state, and the P-wave and S-wave velocities obtained may be unreliable for certain depth intervals near changes in stratigraphy (2). Note 1—The quality of the results produced by these test methods is dependent on the competence of the personnel performing it and the suitability of the equipment and facilities. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection and so forth. Users of these test methods are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.
SCOPE
1.1 These test methods are limited to the determination of the velocity of two types of horizontally travelling seismic waves in soil materials; primary compression (P-wave) and secondary shear (S-wave) waves. The standard assumes that the method used to analyze the data obtained is based on first arrival times or interval arrival times over a measured distance.  
1.2 Acceptable interpretation procedures and equipment, such as seismic sources, receivers, and recording systems are discussed. Other items addressed include borehole spacing, drilling, casing, grouting, deviation surveys, and actual test procedures.  
1.3 These test methods are primarily concerned with the actual test procedure, data interpretation, and specifications for equipment which will yield uniform test results.  
1.4 All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026.  
1.4.1 The procedures used to specify how data are collected/recorded and calculated in these test methods are regarded as the industry standard. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives. Measurements made to more significant digits or better sensitivity than specified in these test methods shall not be regarded a nonconformance with this standard.  
1.5 Units—The values stated in either SI units or inch-pound units [presented in brackets] are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method.  
1.6 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 and health practices and determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
These test methods are limited to the determination of the velocity of two types of horizontally travelling seismic waves in soil materials; primary compression (P-wave) and secondary shear (S-wave) waves. The standard assumes that the method used t...

SIGNIFICANCE AND USE
5.1 Cyclic triaxial strength test results are used for evaluating the ability of a soil to resist the shear stresses induced in a soil mass due to earthquake or other cyclic loading.  
5.1.1 Cyclic triaxial strength tests may be performed at different values of effective confining pressure on isotropically consolidated specimens to provide data required for estimating the cyclic stability of a soil.  
5.1.2 Cyclic triaxial strength tests may be performed at a single effective confining pressure, usually equal to 100 kN/m2 [14.5 lb/in.2], or alternate pressures as appropriate on isotropically consolidated specimens to compare cyclic strength results for a particular soil type with that of other soils, Ref (2).  
5.2 The cyclic triaxial test is a commonly used technique for determining cyclic soil strength.  
5.3 Cyclic strength depends upon many factors, including density, confining pressure, applied cyclic shear stress, stress history, grain structure, age of soil deposit, specimen preparation procedure, and the frequency, uniformity, and shape of the cyclic wave form. Thus, close attention must be given to testing details and equipment.  
5.4 There are certain limitations inherent in using cyclic triaxial tests to simulate the stress and strain conditions of a soil element in the field during an earthquake.  
5.4.1 Nonuniform stress conditions within the test specimen are imposed by the specimen end platens. This can cause a redistribution of void ratio within the specimen during the test.  
5.4.2 A 90° change in the direction of the major principal stress occurs during the two halves of the loading cycle on isotropically consolidated specimens.  
5.4.3 The maximum cyclic shear stress that can be applied to the specimen is controlled by the stress conditions at the end of consolidation and the pore-water pressures generated during testing. For an isotropically consolidated contractive (volume decreasing) specimen tested in cyclic compression, the maximum cy...
SCOPE
1.1 This test method covers the determination of the cyclic strength (sometimes called the liquefaction potential) of saturated soils in either intact or reconstituted states by the load-controlled cyclic triaxial technique.  
1.2 The cyclic strength of a soil is evaluated relative to a number of factors, including: the development of axial strain, magnitude of applied cyclic stress, number of cycles of stress application, development of excess pore-water pressure, and state of effective stress. A comprehensive review of factors affecting cyclic triaxial test results is contained in the literature (1).2  
1.3 Cyclic triaxial strength tests are conducted under undrained conditions to simulate essentially undrained field conditions during earthquake or other cyclic loading.  
1.4 Cyclic triaxial strength tests are destructive. Failure may be defined on the basis of the number of stress cycles required to reach a limiting strain or 100 % pore pressure ratio. See Section 3 for Terminology.  
1.5 This test method is generally applicable for testing cohesionless free draining soils of relatively high permeability. When testing well-graded materials, silts, or clays, pore-water pressures monitored at the specimen ends may not represent pore-water pressure values throughout the specimen. However, this test method may be followed when testing most soil types if care is taken to ensure that problem soils receive special consideration when tested and when test results are evaluated.  
1.6 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026. The procedures in Practice D6026 that are used to specify how data are collected, recorded, and calculated are regarded as the industry standard. In addition, they are representative of the significant digits that should generally be retained. The procedures do not consider material variation, purpose for obtaining ...

SIGNIFICANCE AND USE
5.1 The cyclic triaxial test permits determination of the secant modulus and damping coefficient for cyclic axial loading of a prismatic soil specimen in hydrostatically consolidated, undrained conditions. The secant modulus and damping coefficient from this test may be different from those obtained from a torsional shear type of test on the same material.  
5.2 The secant modulus and damping coefficient are important parameters used in dynamic, performance evaluation of both natural and engineered structures under dynamic or cyclic loads such as caused by earthquakes, ocean wave, or blasts. These parameters can be used in dynamic response analyses including, finite elements, finite difference, and linear or non-linear analytical methods.Note 1—The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.
SCOPE
1.1 These test methods cover the determination of the modulus and damping properties of soils in either intact or reconstituted states by either load or stroke controlled cyclic triaxial techniques. The standard is focused on determining these properties for soils in hydrostatically consolidated, undrained conditions.  
1.2 The cyclic triaxial properties of initially saturated or unsaturated soil specimens are evaluated relative to a number of factors including: strain level, density, number of cycles, material type, and effective stress.  
1.3 These test methods are applicable to both fine-grained and coarse-grained soils as defined by the unified soil classification system or by Practice D2487. Test specimens may be intact or reconstituted by compaction in the laboratory.  
1.4 Two test methods are provided for using a cyclic loader to determine the secant Young's modulus (E) and damping coefficient (D) for a soil specimen. The first test method (A) permits the determination of E and D using a constant load apparatus. The second test method (B) permits the determination of E and D using a constant stroke apparatus. The test methods are as follows:  
1.4.1 Test Method A—This test method requires the application of a constant cyclic load to the test specimen. It is used for determining the secant Young's modulus and damping coefficient under a constant load condition.  
1.4.2 Test Method B—This test method requires the application of a constant cyclic deformation to the test specimen. It is used for determining the secant Young's modulus and damping coefficient under a constant stroke condition.  
1.5 The development of relationships to aid in interpreting and evaluating test results are left to the engineer or office requesting the test.  
1.6 Limitations—There are certain limitations inherent in using cyclic triaxial tests to simulate the stress and strain conditions of a soil element in the field during an earthquake, with several summarized in the following sections. With due consideration for the factors affecting test results, carefully conducted cyclic triaxial tests can provide data on the cyclic behavior of soils with a degree of accuracy adequate for meaningful evaluations of modulus and damping coefficient below a shearing strain level of 0.5 %.  
1.6.1 Nonuniform stress conditions within the test specimen are imposed by the specimen end platens.  
1.6.2 A 90° change in the direction of the major principal stress occurs during the two halves of the loading cycle on isotropically confined specimens.  
1.6.3 The maximum cyclic axial stress that can be applied to a saturated specimen is contro...