Automatic Static and Cyclic Shear Testing Machine under Constant Normal Stiffness Boundary Conditions

2018 ◽  
Vol 41 (3) ◽  
pp. 20170083 ◽  
Author(s):  
S. M. Mahdi Niktabar ◽  
K. Seshagiri Rao ◽  
Amit Kumar Shrivastava
Keyword(s):  
Boundary Conditions ◽  
Testing Machine ◽  
Shear Testing ◽  
Normal Stiffness ◽  
Cyclic Shear ◽  
Constant Normal Stiffness

Shear rupture under constant normal stiffness boundary conditions

2014 ◽  
Vol 634 ◽  
pp. 76-90 ◽  
Author(s):  
R.P. Bewick ◽  
P.K. Kaiser ◽  
W.F. Bawden
Keyword(s):  
Boundary Conditions ◽  
Normal Stiffness ◽  
Shear Rupture ◽  
Constant Normal Stiffness

scholarly journals Research Progress on Shear Characteristics of Rock Joints under Constant Normal Stiffness Boundary Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Guansheng Han ◽  
Fei Xiong ◽  
Yu Zhou ◽  
Leibo Song ◽  
Xingkai Wang
Keyword(s):  
Boundary Conditions ◽  
Rock Joint ◽  
Test System ◽  
Rock Joints ◽  
Research Progress ◽  
Shear Tests ◽  
Underground Engineering ◽  
Normal Stiffness ◽  
Shear Characteristics ◽  
Constant Normal Stiffness

The constant normal stiffness (CNS) boundary condition is more representative for the underground engineering, in which the shear-induced dilation is restricted by surrounding rocks, resulting in an increase in the normal stress. Therefore, the use of CNS boundary conditions in the research of shear-slip failure of underground rock engineering is more in line with the actual situation. Taking the instability and failure of surrounding rock in underground engineering as the background, the present study introduces the engineering background of CNS boundary conditions and the research progress on shear characteristics of rock joints under CNS boundary conditions. Three key directions for future research are proposed based on the latest research results of shear characteristics of rock joint under CNS boundary conditions: ① developing a rock joint shear test system that can realize the function of “CNS boundary conditions + shear-seepage test + visualization”; ② carrying out the shear tests of real rock joints under CNS boundary conditions based on 3D scanning and 3D carving technology; and ③ carrying out the shear tests of rock joint network under CNS boundary conditions.

scholarly journals Experimental Study on the Shear-Flow Coupled Behavior of Tension Fractures Under Constant Normal Stiffness Boundary Conditions

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 57 ◽  
Author(s):  
Changsheng Wang ◽  
Yujing Jiang ◽  
Hengjie Luan ◽  
Jiankang Liu ◽  
Satoshi Sugimoto
Keyword(s):  
Surface Roughness ◽  
Shear Stress ◽  
Shear Flow ◽  
Boundary Conditions ◽  
Normal Stress ◽  
Growth Stage ◽  
Normal Stiffness ◽  
Peak Shear Stress ◽  
Hydraulic Aperture ◽  
Constant Normal Stiffness

This study experimentally investigated the effects of fracture surface roughness, normal stiffness, and initial normal stress on the shear-flow behavior of rough-walled rock fractures. A series of shear-flow tests were performed on two rough fractures, under various constant normal stiffness (CNS) boundary conditions. The results showed that the CNS boundary conditions have a significant influence on the mechanical and hydraulic behaviors of fractures, during shearing. The peak shear stress shows an increasing trend with the increases in the initial normal stress and fracture roughness. The residual shear stress increases with increasing the surface roughness, normal stiffness, and initial normal stress. The dilation of fracture is restrained more significantly under high normal stiffness and initial normal stress conditions. The hydraulic tests show that the evolutions of transmissivity and hydraulic aperture exhibit a three-stage behavior, during the shear process—a slight decrease stage due to the shear contraction, a fast growth stage due to shear dilation, and a slow growth stage due to the reduction rate of the mechanical aperture increment. The transmissivity and hydraulic aperture decreased, gradually, as the normal stiffness and initial normal stress increase.

Sign in / Sign up

Export Citation Format

Share Document