JGS 0543-2020

Japanese Geotechnical Society Standard (JGS 0543-2020)
Method for cyclic torsional shear test on hollow cylindrical specimens todetermine deformation properties of soils
1

Scope

This standard specifies a test method to obtain the deformation properties in cyclic loading of soils consolidated
under isotropic stress or anisotropic stress conditions, under drained states or undrained states, using cyclic
torsional shear equipment. The standard applies to cohesive soils and sandy soils.
Note 1: This standard applies to saturated specimen. Also this standard can be applied to specimen in the air dried stateand in the unsaturated state.
Note 2: This standard is also applicable to other geomaterials.

2

Normative references

The following standards shall constitute a part of this standard by virtue of being referenced in this standard.
The latest versions of these standards shall apply (including supplements).
The specimen to be used in this test shall be prepared and installed in accordance with the following standard.
JGS 0550

Practice for preparing hollow cylindrical specimens of soils for torsional shear test

When executing this test, the following standards shall be referred to for matters not prescribed in this standard.
JGS 0541
JGS 0542
JGS 0551

3

Method for cyclic undrained triaxial test on soils
Method for cyclic triaxial test to determine deformation properties of geomaterials
Method for torsional shear test on hollow cylindrical specimens of soils

Terms and definitions

In addition to those specified in JIS A 0207, the main terminology and definitions used in this standard shall be
as follows.

3.1

Cyclic torsional shear test on hollow cylindrical specimens to determine deformation
properties

A test in which a constant-amplitude symmetrical cyclic torque is applied at a constant period to a horizontal
plane in a hollow cylindrical specimen that has been isotropically or anisotropically consolidated, under drainedor undrained states.
Note: Instead of a constant amplitude cyclic torque, a constant amplitude cyclic torsional displacement may be applied.

3.2

Deformation properties

The equivalent shear modulus obtained from the cyclic shear stress amplitude and the cyclic shear strain
amplitude, and the hysteretic damping factor obtained from the shear stress and shear strain hysteresis curve.

3.3

Axial stress

The stress acting on the specimen in the cylinder axis direction.

3.4

External pressure and internal pressure

The pressure acting on the specimen external lateral surface and hollow part, respectively.
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3.5

Lateral stress

When the external pressure and the internal pressure are equal, they are referred to as the lateral stress. The
value of the stress is defined at the mid-height of the specimen.

3.6

Back pressure

The pore water pressure applied to a specimen (refer to JIS A 1227).
Note: In this standard, the back pressure means the pore water pressure applied to the specimen to achieve a higher
degree of saturation of the specimen while maintaining a constant effective stress.

3.7

Anisotropic consolidation stress ratio

The effective lateral stress divided by the effective axial stress at completion of consolidation.

3.8

Consolidation stress

The stress in a soil element, leading to its consolidation.
Note: In this standard, the consolidation stress means the difference between the externally applied stress on the specimen
and the back pressure during the consolidation process.

3.9

Axial consolidation stress

The value of the consolidation stress on the specimen acting in the cylinder axis direction.

3.10 Lateral consolidation stress
The value of the consolidation stress on the specimen acting in the radial direction.

4

Equipment

The cyclic torsional shear testing equipment is configured from a pressure cell; an external pressure, internalpressure, and back pressure supply device; a torque and axial force loading device; and external pressure,internal pressure, torque, axial force, rotational angle, axial displacement, specimen volumetric change, andpore water pressure measuring and recording equipment, satisfying the following conditions. Figure 1 shows
an example of cyclic torsional shear test equipment. It may include capability of measuring volume changes of
the hollow part of the specimen.
a)

The equipment shall have sufficient load endurance and load capability with respect to the maximum
external pressure, internal pressure, and back pressure, and the maximum torque and axial load applied
to the specimen. The pressure cell shall be fixed to a loading platform or similar, so that the pressure cell
does not rotate when the torque is acting.

b)

The specimen shall be covered with a cap, a pedestal, and rubber sleeves, the prescribed externalpressure, internal pressure, back pressure, torque, and axial force shall be capable of being applied to this,and water shall be capable of being supplied to or drained from the top and bottom ends of the specimen.
The external diameter and the internal diameter of the cap and the pedestal shall be the same as theexternal diameter and internal diameter of the specimen as standard. The two surfaces of the cap and thepedestal shall be flat and parallel to each other, and shall be normal to the axial direction of the loading
piston. A porous plate with metal ribs and having sufficiently high water permeability shall be used as thedrainage surface, and when necessary appropriate filter paper shall be placed there. However, sliding shallnot occur between the specimen and the cap or the pedestal, and another format may be used provided
excessive disturbance is not caused to the specimen. Also, when the cyclic loading test is carried out inthe undrained state, the volumetric change of the pore water pressure measurement path due to changes
in water pressure shall be sufficiently small.

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Note:

The volumetric change properties of the pore water pressure measurement path due to changes in water pressure

shall preferably comply with Note of Section 4b) of JGS 0541 Method for cyclic undrained triaxial test on soils.

c)

The apparatus shall be capable of continuously applying the prescribed external pressure, internalpressure, back pressure, and axial stress during isotropic or anisotropic consolidation with fluctuations ofpressure within ±2 kN/m2 for less than 200 kN/m2, and within ±1% for 200 kN/m2 and higher. Also duringconsolidation it shall be capable of measuring the axial displacement and volumetric change of thespecimen to within an allowable tolerance of 0.02% and 0.05% of the specimen height and volume
respectively. The volumetric change of the specimen during isotropic or anisotropic consolidation shall bemeasured by a burette or a measuring device with equal or better performance.

Note: The burette shall be capable of applying the back pressure, and it is desirable that it has a structure such that thewater level within the burette does not change due to changes in back pressure.

d)

The torque during cyclic loading shall satisfy the following specifications.
1)

After isotropic or anisotropic consolidation, it shall be possible to continuously apply a constant
amplitude cyclic torque with a one-sided shear strain (γ)SA as defined in Section 5.4 ranging from0.001% or less to 0.1% or more, with a constant application period under drained or undrained
conditions.

2)

The wave form shall be a sine wave or a triangular wave, and the frequency shall be 0.05 to 1.0 Hz
as standard. The loading frequency need not be in the range 0.05 to 1.0 Hz, provided it has been
confirmed that the measurement accuracy prescribed in this standard can be satisfied. A rectangularwave or a trapezoidal wave shall not be used as the cyclic torque load wave form instead of the sine
wave or the triangular wave. The following conditions shall always be satisfied during cyclic loading.

3)

The cyclic loading should satisfy the following conditions.

3.1)

The fluctuation of the sum (TR + TL) of the one-sided amplitude TR of the clockwise torque and theone-sided amplitude TL of the counterclockwise torque TL defined from the stress state at the startof cyclic loading shall be 10% or less.

3.2)

0.8  TR / TL  1.2

The one-sided amplitude TR of the torque in the clockwise direction and the one-sided amplitude TL of
the torque in the counterclockwise direction are defined from the stress state prior to cyclic loading as
shown in Figure 2. Both have positive values. T (=TR + TL) is the double-sided amplitude of the cyclic
torque.
e)During cyclic loading the apparatus shall be capable of continuously applying the external pressure andthe internal pressure within a range of pressure fluctuation of ±2 kN/m2 for pressures less than 200 kN/m2,
and ±1% for pressures 200 kN/m2 or higher.

f)During cyclic loading the apparatus shall be capable of continuously measuring the external pressure andthe internal pressure (and the pore water pressure also for the undrained cyclic loading test) to within anallowable tolerance of 2 kN/m2 for pressures less than 200 kN/m2, and 1% for pressures 200 kN/m2 or
higher.

g)

Measurement of the torque during cyclic loading shall satisfy the following specifications.
1)

When cyclic loading with a one-sided shear strain (γ)SA of 0.01% or more is applied, the apparatus
shall be capable of continuously measuring the cyclic torque acting on the specimen to within anallowable tolerance of 1% of the double-sided amplitude of the prescribed torque, using a torque meter
whose hysteresis properties can be ignored, installed within the pressure cell.

2)

An electrical torque meter installed within the pressure cell shall be used for measurement of the cyclic
torque.

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3)

The torque meter output shall not change due to changes in the external pressure. It shall not beaffected by the axial force either. In addition, during cyclic loading for each wave, the measured torqueshall not have a drift of 1% or more, and a calibrated value change of 1% or more, of that measured
during a cycle with one-sided shear strain (γ)SA of 0.01%.

4)

The relationship between the torque meter output and the actual torque shall be obtained for loading
and unloading and the hysteresis property hLC obtained for cyclic loading shall be obtained by themethod shown in Figure 3. It shall be confirmed that the value of hLC is 5% or less of the hysteretic
damping factor h of the specimen when the one-sided amplitude shear strain (γ)SA is 0.01%. The
maximum value of the torque applied to the torque meter shall be the maximum value of the torqueapplied in the actual test.
Torque meter hysteresis property hLC = (1/2π)∙X/X

h)The rotation measurement during cyclic loading shall satisfy the following specifications.
1)

During cyclic loading with a one-sided amplitude shear strain (γ)SA of 0.01% or more, the apparatus
shall be capable of continuously measuring the rotational angle to within an allowable tolerance of 1%of the double-sided amplitude of the prescribed rotational angle, using a rotational angle measuring
device whose hysteresis properties can be ignored. For one-sided amplitude shear strains (γ)SA ofless than 0.1%, the rotational angle of the cap can be directly measured by the rotational angle
measuring device installed within the pressure cell.

2)

If the rotational angle of the specimen during cyclic loading is measured with an electrical rotational
angle measuring device installed outside the pressure cell, the deformation of the loading piston,
torque meter, etc., located between the rotational angle measuring device and the specimen, and thedeformation of the fixing position of the rotational angle measuring device, etc., shall be 1% or less of
the rotational angle of the specimen when the one-sided shear strain (γ)SA is 0.1%.

3)

The output of the rotational angle measuring device shall not change due to changes in the cellpressure. In addition, during cyclic loading for each wave, the measured rotation shall not have a drift
of 1% or more, and a calibrated value change of 1% or more, of that measured during a cycle with
one-sided shear strain (γ)SA of 0.01%.

4)

The relationship between the rotational angle measuring device output and the rotational angle applied
to the rotational angle measuring device shall be obtained by increasing and decreasing the static
rotational angle, and the hysteresis property hDT obtained for cyclic loading shall be obtained by themethod shown in Figure 4. It shall be confirmed that the value of hDT is 5% or less of the hysteretic
damping factor h of the specimen when the one-sided amplitude shear strain (γ)SA is 0.01%. The
maximum value of the applied rotational angle shall be the maximum value of the rotational angle
applied in the actual test.
Rotational angle measurement device hysteresis property hLC = (1/2π)∙Y/Yi)

4

Data recording during cyclic loading shall satisfy the following specifications.
1)

The apparatus shall be capable of continuously and simultaneously recording the cyclic torque andthe cyclic rotational angle. If necessary it shall be capable of continuously recording the pore waterpressure.

2)

During cyclic loading the measured values of torque, rotational angle, and if necessary the externalpressure, internal pressure, and pore water pressure shall be continuously recorded using an electrical
recording device such as a digital data recorder. The number of data points in one cycle shall be 40
or more, so that it is possible to sufficiently interpolate values between two consecutive digital
measurement values.

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3)

It shall be confirmed that the error in the hysteretic damping factor due to phase shift between themeasured results of torque and rotational angle is not more than 5% of the hysteretic damping factorof the specimen when the one-sided shear strain (γ)SA is 0.01%. If the hysteretic damping factor
linearly increases (decreases) as the frequency increases when a non-viscous specimen is tested,
there is likely to be a time delay (advance) between the records of torque T and rotational angle θ
(Figure 5).

5

Test method

5.1

Preparation and installation of the specimen

Preparation and installation of the specimen shall be carried out in accordance with the method specified by
JGS 0550 Practice for preparing hollow cylindrical specimens of soils for torsional shear test.

5.2

Checking the specimen saturation

The pore water pressure coefficient B (B value) shall be measured prior to consolidation, and if necessary after
consolidation. The B value shall be obtained by the method described in Section 5.2 of JGS 0541 Method for
cyclic undrained triaxial test on soils. However, if anisotropic consolidation is being carried out, the B value shallbe measured during the isotropic consolidation prior to the anisotropic consolidated state.

5.3

Consolidation process

Isotropic consolidation or anisotropic consolidation shall be carried out in accordance with the test objectives.
The axial displacement of the specimen Hc (mm) and the volumetric change of the specimen Vc (mm3) due
to consolidation shall be measured. During consolidation the back pressure shall be constant.
Note: This shall be carried out in accordance with Section 5.3 of JGS 0551 Method for torsional shear test on hollow
cylindrical specimens of soils.

a)

b)

5.4

Isotropic consolidation process1)

In the drained state, the lateral stress shall be increased while maintaining the isotropic stress state,
until the prescribed value at completion of consolidation is reached.

2)

Consolidation shall continue until completion of primary consolidation at least.

Anisotropic consolidation process1)

In the drained state, the axial stress shall be increased so as to satisfy the prescribed anisotropic
consolidation stress ratio relative to the effective lateral stress in the initial isotropic consolidationstress state.

2)

The lateral stress and the axial stress shall be increased in stages in the combination to obtain theprescribed anisotropic consolidation stress ratio, until the final anisotropic consolidation stress state isreached.

3)

Consolidation shall continue until completion of primary consolidation at least.

Cyclic loading process

The cyclic loading process shall be carried out in accordance with the following requirements.
a)

Check that the state is the prescribed isotropic or anisotropic stress state.

b)

Apply the cyclic torsional load in accordance with the following requirements 1) to 3). The axial stress during
the cyclic loading shall be kept constant within an allowable tolerance of 2 kN/m2 for pressures less than
200 kN/m2, and ±1% for pressures 200 kN/m2 or higher.

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JGS 0543-2020

Note 1: The maximum cyclic torque amplitude may be determined as appropriate in accordance with the state of thespecimens and the objectives of the test.
Note 2: Figure 6 shows an example of record of the cyclic torsional shear test.

1)

First loading

1.1)

For an undrained test, the drainage valve shall be closed.

1.2)

Apply 11 cycles of cyclic torque with a sinusoidal or triangular wave form with a constant amplitude
and a constant frequency in the range 0.05 to 1.0 Hz, so that the one-sided shear strain (γ)SA is
0.001% or less. During loading the cyclic torque, the rotational angle, and if necessary the porewater pressure shall be continuously recorded.

1.3)

The change in the height and the change in the volume of the specimen due to the cyclic loading
shall be measured. When undrained conditions are applied during cyclic loading, the drainage
valve shall be opened and any excess pore water pressure shall be dissipated. The change inheight and the change in volume of the specimen that occurs as a result shall be measured.

2)

Second loading

2.1)

For an undrained test, the drainage valve shall be closed.

2.2)

The cyclic loading shall be carried out in the same way as the first loading, so that the one-sided
shear strain (γ)SA is about double that in the first loading.

2.3)

The change in the height and the change in the volume of the specimen due to the cyclic loading
shall be measured. When undrained conditions are applied during cyclic loading, the drainage
valve shall be opened and any excess pore water pressure shall be dissipated. The change inheight and the change in volume of the specimen that occurs as a result shall be measured.

3)

Third and subsequent loadings
The loading shall be applied in the same way as for the second loading. The loading shall repeat thiscyclic loading stage as much as possible.

c)

The state of deformation of the specimen shall be observed and recorded.

d)

The oven dried mass of the specimen ms (g) shall be measured.

6

Processing test results

6.1

Specimen state prior to consolidation

The state of the specimen prior to consolidation shall be obtained from the following equations.
a)

The volume of the specimen prior to consolidation V0 (mm3) shall be calculated from the following equation.

V0 = Vi − Vi
where

Vi : Initial volume of the specimen (mm3)Vi : Volumetric change in the specimen produced from the initial state until prior to consolidation(mm3) (volume reduction is taken positive)b)

The height of the specimen H0 (mm) prior to consolidation shall be calculated from the following equation.

H0 = Hi − Hi

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JGS 0543-2020

where

Hi : Initial height of the specimen (mm)Hi : Change in height of the specimen produced from the initial state until prior to consolidation (mm)(compression is taken positive)c)

The external diameter Do0 (mm) and the internal diameter Di0 (mm) of the specimen prior to consolidation
shall be calculated from the following equations.
Do0 = Doi × √(1 − εvi /100)/(1 − εai /100)
Di0 = Dii × √(1 − εvi /100)/(1 − εai /100)
where
Do0:
Di0:
εvi:
εai:

6.2

Initial external diameter of the specimen (mm)Initial internal diameter of the specimen (mm)Volumetric compressive strain (%) produced from the initial state until prior to consolidation(=Vi /Vi)
Axial compressive strain (%) produced from the initial state until prior to consolidation(=Hi /Hi)

Pore water pressure coefficient B

The B value of the specimen shall be calculated as follows, and the value shall be rounded to two significant
digits.
B=

∆u
∆σ

where

σ:
u:

6.3

Increment of isotropic stress (kN/m2)
Increment of pore water pressure associated with σ (kN/m2)

Consolidation process

The method of calculating and analyzing the consolidation process shall be as follows.
a)

The volume of the specimen Vc (mm3) after consolidation shall be calculated from the following equation.

VC = V0 − VC
whereVc : Volumetric change due to consolidation (mm3) (volume reduction is taken positive)b)

The specimen height Hc (mm) after consolidation shall be calculated from the following equation.

HC = H0 − HC
whereHc: Axial displacement due to consolidation (mm) (compression is taken positive)c)

The specimen cross-sectional area Ac (mm2) after consolidation shall be calculated from the following
equation.

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VC
HC

AC =
d)

The specimen external diameter Doc (mm) and internal diameter Dic (mm) after consolidation shall becalculated from the following equations.
Doc = Do0 × √(1 − εvc /100)/(1 − εac /100)
Dic = Di0 × √(1 − εvc /100)/(1 − εac /100)
where
εvc :
εac :

e)

Volumetric compressive strain (%) due to consolidation (=Vc /V0)
Axial compressive strain due to consolidation (=Hc /H0)

The dry density ρdc (Mg/m3) of the specimen after consolidation shall be calculated from the following
equation.
ms
× 1000
Vc

ρdc =

where
ms:

Oven-dried mass of the specimen (g)Note: If necessary, the void ratio ec and the relative density Drc (%) of the specimen after consolidation shall be calculated
from the following equations.

ec =Vc /1000 × ρs
−1
ms

Dr c =

emax − ec 100emax − emin

where
ρs :
Soil particle density (Mg/m3)
emax: Void ratio of the sample from a minimum density test
emin: Void ratio of the sample from a maximum density test

6.4

Cyclic loading process

The method of calculating and analyzing the cyclic loading process shall be as follows.
a)

The volume Vn (mm), height Hn (mm), cross-sectional area An (mm2), external diameter Don (mm), andinternal diameter Din (mm), of the specimen at the start of each loading stage carried out with constant
amplitude cyclic torque shall be calculated.

Note: If necessary the void ratio en at the start of each loading stage shall be calculated from the following equation. The
void ratio en at the start of the initial cyclic loading stage is equal to the void ratio ec after consolidation.

en =
1)

8

Vn /1000 × ρs
−1ms

The specimen volume Vn (mm3) at the start of each loading stage shall be calculated from the following
equation.

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JGS 0543-2020

Vn = Vc − VnwhereVn: Volumetric change in the specimen from completion of consolidation until commencementof each loading stage (mm3) (volume reduction is taken positive)
2)

The specimen height H n (mm) at the start of each loading stage shall be calculated from the following
equation.

Hn = Hc − HnwhereHn: Axial displacement from completion of consolidation until commencement of each loading
stage (mm) (compression is taken positive)
3)

The specimen cross-sectional area An (mm2) at the start of each loading stage shall be calculated fromthe following equation.

An =

4)

Vn
Hn

The specimen external diameter Don (mm) and internal diameter Din (mm) at the start of each loading
stage shall be calculated from the following equation.
Don = Doc × √(1 − εvn /100)/(1 − εan /100)
Din = Dic × √(1 − εvn /100)/(1 − εan /100)
where
εvn :
εan :

b)

Volumetric compressive strain (%) from completion of consolidation until the start of eachloading stage (=Vn /Vc)
Axial compressive strain (%) from completion of consolidation until the start of each loading
stage (=Hn /Hc)

In each cyclic loading stage in which a cyclic torque with a constant amplitude is applied, the one-sided
shear stress amplitude 𝜏d (kN/m2), the one-sided shear strain amplitude (γ)SA (%), the equivalent shear
modulus Geq (MN/m2), and the hysteretic damping factor h (%) shall be calculated for the 5th and 10th
loading cycles.

Note: Depending on the objectives of the test, the equivalent shear modulus Geq (MN/m2) and the hysteretic damping factor
h (%) may be calculated at loading cycles other than the 5th and 10th loading cycles.

1)

The one-sided amplitude of the cyclic shear stress 𝜏d (kN/m2) shall be calculated from the following
equation. The calculated value shall be rounded to three significant digits. When it is beyond theprecision of the measuring devices, it shall be rounded to two significant digits.
𝜏d =TR + TL× 106
22π(ron + rin2 )(ron +rin )where© JGS 2018 – All rights reserved

9JGS 0543-2020

TR, TL:The right and left one-sided cyclic torque amplitude (N∙m) in that loading cycle (eachhaving positive values)
Specimen external radius at start of that cyclic loading stage (m) (= Don/2)
Specimen internal radius at start of that cyclic loading stage (m) (= Din/2)

ron :
rin :
2)

The one-sided shear strain amplitude (γ)SA (%) shall be calculated from the following equation androunded to three significant digits. When it is beyond the precision of the measuring devices, it shallbe rounded to two significant digits.
(γ)SA =

θ(ron +rin )
4Hn

× 100

where

θ:
Hn :
3)

Double-sided amplitude of rotational angle of specimen in that loading cycle (rad)Specimen height at the start of that cyclic loading stage (mm)The equivalent shear modulus Geq (MN/m2) shall be calculated from the following equation androunded to three significant digits. When it is beyond the precision of the measuring devices, it shallbe rounded to two significant digits.
Geq =

𝜏d
1
×
(γ)SA 10

Note: Figure 7 is an explanatory diagram for the equivalent shear modulus Geq (MN/m2) showing an example of hysteresis
curve drawn from the shear stress and shear strain obtained using the specimen height, external diameter, and internal
diameter at the start of that loading cycle.

4)

The hysteretic damping factor h (%) shall be calculated from the following equation and rounded tothree significant digits. When it is beyond the precision of the measuring devices, it shall be rounded
to two significant digits.

h=

1 W
・
 100
2 W

where

W: The damping energy in that loading cycle, given by the area (N∙m) of the hysteresis curve
produced with the torque T and the rotational angle θ

Note 1:W:

The equivalent elastic energy in that loading cycle, calculated from the following equationW=(TR + TL )θ(N∙m)
4

Figure 8 is a diagram explaining the hysteretic damping factor h=(1/2π)∙ΔW/W.

Note 2: When the hysteresis curve does not close, as shown in Figure 9, W (N∙m) shall be taken to be the sum of thearea of the hysteresis curve gbh and the area of the hysteresis curve hdf.

7

Reporting

The following items of the test results shall be reported.
a)Method of preparation of the specimenb)Specimen dimensions prior to consolidation

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JGS 0543-2020c)

B value and its method of measurementd)Volumetric change (mm3) and axial displacement (mm) due to consolidation

Note: If consolidation required a long period of time, such as for cohesive soils, etc., the relationship between time (min)and the axial displacement (mm) or the volumetric change (mm3) shall also be reported.

e)Oven-dried mass (g) of the specimen and dry density (Mg/m3) after consolidation

Note: If necessary, the void ratio and relative density (%) after consolidation shall be reported.

f)

The magnitude of the axial stress (kN/m2), external pressure (kN/m2), internal pressure (kN/m2), and backpressure (kN/m2) after consolidationg)

The axial consolidation stress σ'ac (kN/m2), the lateral consolidation stress σ'rc (kN/m2), and if necessary
the anisotropic consolidation stress ratio σ'rc /σ'ac (= K)h)

The loading frequency, loading wave form, and drainage states during cyclic loadingi)

Method of measurement of the torque and rotational angle during cyclic loading

Note: The position of the torque meter and rotational angle measuring device within the pressure cell shall be reported.

j)Dimensions of the specimen at the start of each of the second to final cyclic loading stages

Note: If necessary, the void ratio at the start of each loading stage shall also be reported.

k)Torque and rotational angle time history in each loading stage, and the hysteresis curve for the torque androtational angle in the 5th and 10th loading cycles

Note: The time history and hysteresis curve for the shear stress and the shear strain may also be reported. The 10th loading
cycle can be taken to be the representative value, and the 5th to be a reference value.

The equivalent shear modulus Geq (MN/m2), the hysteretic damping factor h (%), and the corresponding
one-sided shear strain amplitude (γ)SA (%) at the 5th and 10th loading cycles in each cyclic loading stagel)Note: If necessary, the equivalent shear modulus Geq (MN/m2), the hysteretic damping factor h (%), and the corresponding
one-sided shear strain amplitude (γ)SA (%) at all the 2nd to 10th loading cycles shall be reported.

m) Relationship between the equivalent shear modulus Geq (MN/m2), the hysteretic damping factor h (%), andthe logarithm of the one-sided shear strain amplitude (γ)SA (%) in the 5th and 10th loading cycles
Note: Figure 10 shows a standard example of a summary of a series of test results.

n)

If a method that partially differs from this standard was used, give details of the points of difference.

o)Other reportable matters, including the following
1)

an outline of the test equipment, the method of saturating the specimen, the hysteresis properties of
the torque meter and the rotational angle measuring device, and the material and thickness of therubber sleeve.

2)

The dimensions, positions, and number of the metal ribs embedded in the porous plate, or the statusof the slip prevention used instead of the metal ribs.

3)

The state of alternation of strata in the specimen, the state of deformation, such as necking, etc.

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JGS 0543-2020

Axial load application device

Torque application device
Loading frame

Axial displacement gauge(small-large strain)
External pressure(air pressure)
Load cell, torque meter

Axial displacement gauge(very small - small strain)

Rotational angle measuring device(small-large strain)

Rotational angle measuring device(very small - small strain)

Internal pressure(air pressure)

Pore water pressure
measuring device

Double-walled tube
burettePedestal

Water

Specimen

Double-walled tube
buretteCap

Back pressure(air pressure)Internal pressure
measuring device
Loading platform

TorqueFigure 1 Example of cyclic torsional shear test equipment

Time

Figure 2 Definition of clockwise one-sided torque amplitude TR and counterclockwise onesided torque amplitude TL for sinusoidal cyclical torque

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JGS 0543-2020

Torque meter output
X = [Δabc area] + [Δdae area]

Torque applied to torque meter
Hysteresis area ΔX

Figure 3 Definition of torque meter hysteresis properties

Rotational angle measuring
device output

Y = [Δabc area] + [Δdae area]

Rotational angle applied to rotational
angle measuring device
Hysteresis area ΔY

Figure 4 Definition of rotational angle measuring device hysteresis properties

When rotational
angle isrecorded late.

When torque is recordedlate.

Figure 5 Apparent dependence on loading frequency f of h measured from the phase shift
between the measured results for the torque and the rotational angle when h has nofrequency dependence (h0 is the correct value, hd is the apparent value at f1)© JGS 2018 – All rights reserved

13

Toyoura sand, air-pluviation method, ec = 0.678, σc' = 98 kN/m2
f = 0.1 Hz, H = 20 cm, Do = 10 cm, Di = 6 cm

Shear strain γ (%)

Shear stress τ (kN/m2)

JGS 0543-2020

Figure 6 Example of cyclic torsional shear test record when wave form is a sine wave

Shear stress τ (kN/m2)

10th cyclic load

Shear strain γ (%)

Figure 7 Example of typical hysteresis curve

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Cylic torque T acting on specimen
T (N∙m)W = [Δabc area] + [Δdae area]

Rotational angle θ of specimen
Hysteresis area ΔW

Figure 8 Explanatory diagram for the hysteretic damping factor hCylic torque T acting on specimen
T (N∙m)Rotational angle θ of specimen
Hysteresis area ΔW

Toyoura sand, air-pluviation method, ec = 0.688, σc' = 98 kN/m2
f = 0.1 Hz, H = 200 mm, Do = 100 mm, Di = 60 mm(Drained load)○: 10th cyclic load△: 5th cyclic load

Hysteretic damping factor h (%)

Equivalent shear modulus Geq (MN/m2)

Figure 9 Explanatory diagram for the hysteretic damping factor h when the hysteresis
curve does not close

One-sided shear strain amplitude (γ)SA (%)

Figure 10 Example of summary of series of test results© JGS 2018 – All rights reserved

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