Macro–micro responses of crushable granular materials in simulated true triaxial tests

2015 ◽  
Vol 17 (4) ◽  
pp. 497-509 ◽  
Author(s):  
Wei Zhou ◽  
Lifu Yang ◽  
Gang Ma ◽  
Xiaolin Chang ◽  
Yonggang Cheng ◽  
...  
Keyword(s):  
Granular Materials ◽  
Triaxial Tests ◽  
True Triaxial ◽  
True Triaxial Tests

Simulation of triaxial and true triaxial tests on natural and reconstituted Pisa clay

Géotechnique ◽  
2002 ◽  
Vol 52 (9) ◽  
pp. 649-666 ◽  
Author(s):  
L. Callisto ◽  
A. Gajo ◽  
D. Muir Wood
Keyword(s):  
Triaxial Tests ◽  
True Triaxial ◽  
True Triaxial Tests

scholarly journals Research on the Reasonable Strengthening Time and Stability of Excavation Unloading Surrounding Rock of High-Stress Rock Mass

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wensong Xu ◽  
Wentao Xu ◽  
Yunhai Cheng
Keyword(s):  
Rock Mass ◽  
Plastic Zone ◽  
Failure Process ◽  
High Stress ◽  
Stable State ◽  
Surrounding Rock ◽  
Triaxial Tests ◽  
Uniaxial Compression Test ◽  
True Triaxial ◽  
True Triaxial Tests

This study is aimed at better understanding the deformation and failure mechanism of surrounding rock during excavation unloading of a high-stress rock mass and determining the reasonable reinforcement time for the surrounding rock. To fulfill this aim, true triaxial tests were carried out on different loading and unloading paths during the unilateral unloading of a high-stress rock mass. The variational condition for minimization of plastic complementary energy is obtained, the optimal reinforcement time is determined, and the range of the plastic zone in the surrounding rock reinforced by anchor mesh-cable-grouting is compared and analyzed. The results are as follows: (1) Based on the Mohr-Coulomb yield criterion and the deformation reinforcement theory of surrounding rock, the stable state with the minimum reinforcement force is obtained. (2) After the true triaxial tests on the unilateral unloading of the third principal stress were carried out under different confining pressures, loading continued to be performed. Compared with rock failure without confining pressure, in the conventional uniaxial compression test, the failure of samples is dominated by composite splitting-shear failure; the unilateral unloading stress-concentration failure is a progressive failure process of splitting into plates followed by cutting into blocks and then the ejection of blocks and pieces. (3) The relationship between the time steps of the surrounding rock stability and the excavation distance is obtained. The supporting time can be divided into four stages: presupport stage, bolt reinforcement stage, anchor cable reinforcement stage, and grouting reinforcement stage. (4) In the range of within 5 m behind the tunneling face, the plastic zone of the surrounding rock with support is reduced by 7 m as compared with that with no support. In the range of over 5 m behind the tunneling face, the plastic zone of the roadway floor with support is reduced by 2.6 m as compared with that without support, and the deformation is reduced by 90%. These results can serve as a reference for controlling the behavior of surrounding rock during excavation unloading of high-stress rock masses.

Shear Band Formation and Strength of Loess in True Triaxial Tests

2019 ◽  
Vol 47 (4) ◽  
pp. 20160506 ◽  
Author(s):  
Sheng-jun Shao ◽  
Fei Chen ◽  
Shuai Shao
Keyword(s):  
Shear Band ◽  
Triaxial Tests ◽  
Shear Band Formation ◽  
Band Formation ◽  
True Triaxial ◽  
True Triaxial Tests
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