scholarly journals Discussion: Radial Strain Behaviors and Stress State Interpretation of Soil Under Direct Simple Shear*

2016 ◽  
Vol 45 (2) ◽  
pp. 20150447
Author(s):  
Y. Li ◽  
Y. M. Yang ◽  
G. W. Roberts ◽  
H. S. Yu
Keyword(s):  
Stress State ◽  
Simple Shear ◽  
Radial Strain ◽  
Direct Simple Shear ◽  
State Interpretation

scholarly journals Effects of Spatially Varying Seismic Ground Motions and Incident Angles on Behavior of Long Tunnels

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Yundong Zhou ◽  
Yongxin Wu ◽  
Ziheng Shangguan ◽  
Zhanbin Wang
Keyword(s):  
Stress State ◽  
Strain Rate ◽  
Ground Motions ◽  
Pure Shear ◽  
Radial Strain ◽  
Complex Stress State ◽  
Asymmetric Effect ◽  
Principal Stresses ◽  
Input Motion ◽  
Spatially Varying

Seismic behavior of long circle tunnels is significantly influenced by the nature of input motion. This study, based on the 3D finite-element method (FEM), evaluates the effects of spatially varying seismic ground motions and uniform input seismic ground motions and their incident angles on the diameter strain rate and tensive/compressive principal stresses under different strata. It is found that (1) the spatially varying seismic ground motions induced larger diameter strain rate (radially deformation) than the uniform input seismic motion, (2) the spatially varying seismic ground motions had an asymmetric effect on the radial strain rate distributions, and (3) the rising incident angles changed the pure shear stress state into a complex stress state for tunnels under specified input motion.

scholarly journals The Influence of Apparatus Stiffness on the Results of Cyclic Direct Simple Shear Tests on Dense Sand

2020 ◽  
Vol 44 (5) ◽  
pp. 20190471
Author(s):  
M. Konstadinou ◽  
A. Bezuijen ◽  
G. Greeuw ◽  
C. Zwanenburg ◽  
H. M. Van Essen ◽  
...  
Keyword(s):  
Simple Shear ◽  
Shear Tests ◽  
Dense Sand ◽  
Direct Simple Shear

Water Content of Moist-Tamped Nonplastic Specimens for Constant-Volume Direct Simple Shear Testing

2021 ◽  
Vol 45 (2) ◽  
pp. 20210125
Author(s):  
Jiarui Chen ◽  
Scott M. Olson ◽  
Soham Banerjee ◽  
Mandar M. Dewoolkar ◽  
Yves Dubief
Keyword(s):  
Water Content ◽  
Simple Shear ◽  
Constant Volume ◽  
Shear Testing ◽  
Direct Simple Shear

Cyclic Simple Shear Apparatus for Low-Strain Soil Tests

1996 ◽  
Vol 1548 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Heather J. Miller ◽  
Pedro de Alba ◽  
Kenneth C. Baldwin
Keyword(s):  
Shear Modulus ◽  
Shear Strain ◽  
Simple Shear ◽  
Recovery Period ◽  
Triaxial Tests ◽  
Cyclic Shear ◽  
Aging Period ◽  
Direct Simple Shear ◽  
Fabric Evolution ◽  
Excess Pore Pressures

A testing system has been developed to study the behavior of saturated sand under low-level cyclic shearing strains. The system has been used to determine threshold shear strain levels for fabric destruction in sand aged for different time periods. The system includes a special soil chamber and a direct simple shear (DSS) machine. To impose very small shearing strains, the DSS machine was designed to apply and measure horizontal deformations as small as 0.0005 mm (2 × 10−5 inches). Data obtained to date support the results of previous investigators who performed triaxial tests on freshly deposited samples, indicating a threshold cyclic shear strain level of approximately 0.01 percent. At strains in excess of those levels, destruction of the sand fabric occurred, as evidenced by a reduction in shear modulus at low strain levels. Subsequent modest increases in shear modulus were observed after the specimens were allowed to recover for 24 hours and then tested again. During the recovery period, drainage valves were left open to allow for dissipation of excess pore pressures and for potential consolidation during the short aging period. The DSS system was found to work well for low strain measurements. Furthermore, since shear strains are measured directly under DSS conditions (as opposed to triaxial conditions), the DSS system shows much promise as a device for studying parameters that may influence threshold shear strain levels and fabric evolution and destruction in sands.

Mode of shear effects on yield and liquefied strength ratios

2008 ◽  
Vol 45 (4) ◽  
pp. 574-587 ◽  
Author(s):  
Scott M. Olson ◽  
Benjamin B. Mattson
Keyword(s):  
Simple Shear ◽  
Void Ratio ◽  
Triaxial Compression ◽  
State Parameter ◽  
Sloping Ground ◽  
Direct Simple Shear ◽  
Flow Failure ◽  
Triaxial Extension Test ◽  
Triaxial Extension ◽  
Rotational Shear

A database of 386 laboratory triaxial compression, direct simple shear, rotational shear, and triaxial extension test results was collected to examine yield and liquefied strength ratio concepts used in liquefaction analysis of sloping ground. These data envelope the yield and liquefied strength ratios obtained from back-analyses of liquefaction flow failure case histories. Generally, triaxial compression exhibits the highest yield and liquefied strength ratios, triaxial extension yields the lowest ratios, and direct simple shear – rotational shear shows intermediate responses. However, mode of shear appears to have a considerably smaller effect on laboratory-measured liquefied strength ratios for specimens with a positive state parameter (i.e., difference in consolidation void ratio and steady state void ratio at the same effective stress).

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