Constant-volume friction angle of granular materials

1988 ◽  
Vol 25 (1) ◽  
pp. 50-55 ◽  
Author(s):  
D. Negussey ◽  
W. K. D. Wijewickreme ◽  
Y. P. Vaid
Keyword(s):  
Phase Transformation ◽  
Steady State ◽  
Granular Materials ◽  
Friction Angle ◽  
Confining Pressure ◽  
Constant Volume ◽  
Ring Shear ◽  
Ring Shear Apparatus ◽  
Initial Packing ◽  
Undrained Shear

The postulate that the constant-volume friction angle [Formula: see text] of a granular material is unique and a function of mineral composition is verified experimentally. Granular materials comprised of particles ranging from minerals to metals are tested in a ring shear apparatus. Test samples are subjected to large shear displacements until a constant lower bound friction angle [Formula: see text] is mobilized. Possible effects of confining pressure, initial packing density, gradation, and particle shape on the value of [Formula: see text] are investigated. Friction angles mobilized in drained shear at the instant of maximum contraction and in undrained shear at phase transformation and steady state are compared with [Formula: see text] values. The experimental results confirm a broader fundamental significance of [Formula: see text] as a material parameter in that it is a consistent minimum drained friction angle equal to friction angles mobilized at phase transformation and steady state in undrained shear. Key words: granular materials, sand, friction angles, constant volume, steady state, phase transformation state, ring shear test.

Steady State Strength of Sands in a Constant Volume Ring Shear Apparatus

2002 ◽  
Vol 25 (4) ◽  
pp. 10402
Author(s):  
L David Suits ◽  
TC Sheahan ◽  
VK Garga ◽  
J-A Infante Sedano
Keyword(s):  
Steady State ◽  
Constant Volume ◽  
State Strength ◽  
Ring Shear ◽  
Ring Shear Apparatus

Constant-volume friction angle of granular materials: Reply

1989 ◽  
Vol 26 (1) ◽  
pp. 172-172 ◽  
Author(s):  
D. Negussey ◽  
W. K. D. Wijewickreme ◽  
Y. P. Vaid
Keyword(s):  
Granular Materials ◽  
Friction Angle ◽  
Constant Volume

Performing Undrained Shear Tests on Saturated Sands in a New Intelligent Type of Ring Shear Apparatus

2003 ◽  
Vol 26 (3) ◽  
pp. 10781 ◽  
Author(s):  
L David Suits ◽  
TC Sheahan ◽  
K Sassa ◽  
G Wang ◽  
H Fukuoka
Keyword(s):  
Shear Tests ◽  
Ring Shear ◽  
Saturated Sands ◽  
Ring Shear Apparatus ◽  
Undrained Shear

Constant Volume Ring Shear Apparatus

1996 ◽  
Vol 19 (1) ◽  
pp. 3 ◽  
Author(s):  
RC Chaney ◽  
K Demars ◽  
TD Stark ◽  
IA Contreras
Keyword(s):  
Constant Volume ◽  
Ring Shear ◽  
Ring Shear Apparatus

Geomembrane interface friction

1989 ◽  
Vol 26 (1) ◽  
pp. 165-169 ◽  
Author(s):  
D. Negussey ◽  
W. K. D. Wijewickreme ◽  
Y. P. Vaid
Keyword(s):  
Key Words ◽  
Granular Materials ◽  
Large Strain ◽  
Small Strain ◽  
Interface Friction ◽  
Ring Shear ◽  
Ring Shear Apparatus ◽  
Composite Interfaces ◽  
Peak Resistance

Interface friction between an HDPE geomembrane and an angular as well as a rounded sand, a gravel, and a geotextile was investigated in a ring shear apparatus. The results indicate development of peak resistance at small strain and constant residual interface friction angles at large strain. The magnitude and difference between peak and residual friction angles increase with angularity. Interface friction angles between a geotextile and geomembrane were very low with no distinction between peak and residual. At composite interfaces, sliding occurred much more readily at a finer grained than a coarsegrained geomembrane interface. Key words: geomembranes, geotextiles, interface friction, granular materials.

Post-failure mobility of saturated sands in undrained load-controlled ring shear tests

2002 ◽  
Vol 39 (4) ◽  
pp. 821-837 ◽  
Author(s):  
Gonghui Wang ◽  
Kyoji Sassa
Keyword(s):  
Shear Strength ◽  
Steady State ◽  
Stress State ◽  
Initial Stress ◽  
Shear Behavior ◽  
Shear Tests ◽  
Grain Crushing ◽  
Ring Shear ◽  
Ring Shear Tests ◽  
Undrained Shear

The undrained shear behavior of soils with progress of shear displacement is essential to the understanding of liquefied slope failures with long travel distance. In this paper, using a newly developed ring shear apparatus, a series of ring-shear tests were conducted on a silty sand to examine the undrained behavior of sand subjected to long shear displacement. Based on the test results, the undrained shear behavior of sands with a wide range of densities is discussed. A very low effective stress corresponding to liquefaction was observed at the steady state in all of the tests on loose, medium, as well as dense sand. The effects of stress state and shear history on the undrained shear behavior were examined by performing tests on a sample with different initial stress states and shearing the same specimen repeatedly (three times) at each initial stress state. The tests at different initial stress states proved that the initial stress state has an influence on static liquefaction resistance but has no effect on the steady-state shear strength. Repeated shear tests on the same specimen showed that with increasing shear times, both the peak shear strength and the steady-state shear strength for each specimen became greater. Detailed examination of the shear deformation revealed that the liquefaction phenomena in ring shear tests are localized in the shear zone, irrespective of the initial state of the sand. Grain crushing within the shear zone was examined. Finally, it was found that there was an optimal density at which the undrained brittleness index had a minimum value; meanwhile, the undrained brittleness index became greater with increasing initial normal and shear stresses, but decreased with shear times. These findings offer some basic understanding in assessing the postfailure mobility in landslides.Key words: excess pore pressure, localized liquefaction, shear resistance, ring-shear tests, grain crushing, silty sands.

scholarly journals Shear Strength Behavior of Sand Reinforced by Kraft Paper Using the Ring Shear Apparatus

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Wan-li Xie ◽  
Qianyi Guo ◽  
Nelson N.S. Chou ◽  
Rongsen Zhu ◽  
Maosheng Zhang
Keyword(s):  
Shear Plane ◽  
Friction Angle ◽  
Test Results ◽  
Reinforcement Effect ◽  
Shear Tests ◽  
Kraft Paper ◽  
Ring Shear ◽  
Strength Behavior ◽  
Reinforcement Material ◽  
Ring Shear Apparatus

To explore the reinforcement effects of different reinforcement methods, kraft paper was used as reinforcement material, and shear tests were carried out in sand to study the reinforcement effects of kraft paper perpendicular and parallel to the shear plane. The test results show that the two reinforcement methods can effectively improve the strength of sand and the orthogonal reinforcement form is more superior. The existence of reinforced materials greatly improves the cohesion of sand, but does not significantly improve the internal friction angle. The width of reinforcement material has little effect on the reinforcement effect and shows different variation laws under different reinforcement forms.

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