Analysis of Mechanical Strength and Failure Morphology of Prefabricated Closed Cracked Rock Mass Under Uniaxial Compression

2020 ◽  
Vol 38 (5) ◽  
pp. 4905-4915
Author(s):  
Longyu Zhang ◽  
Jiming Zhu
Keyword(s):  
Rock Mass ◽  
Mechanical Strength ◽  
Uniaxial Compression ◽  
Failure Morphology

scholarly journals Self-potential response characteristics of red sandstone samples under uniaxial compression

2019 ◽  
Vol 16 (4) ◽  
pp. 742-752
Author(s):  
Cai Yang ◽  
Shengdong Liu ◽  
Haiping Yang
Keyword(s):  
Rock Mass ◽  
Uniaxial Compression ◽  
Inflection Point ◽  
Radial Direction ◽  
The Self ◽  
Potential Difference ◽  
Potential Response ◽  
Red Sandstone ◽  
Response Characteristics ◽  
Self Potential

Abstract Deformation and rupture of rock mass under loading cause the variation of electric potential. Response characteristics of self-potential and stress during the complete stress-strain process of red sandstones play an important role in evaluating the stress state of sandstone on the basis of self-potential. Experimental results demonstrate that the stress of red sandstone under uniaxial compression is linearly correlated with the self-potential difference before the first inflection point in the initial stage of loading. The average variation rate of self-potential difference and stress is 0.1325 mV MPa−1. As the loading pressure gradually increases and enters the softening stage (before the maximum loading point), the catastrophic points of uniaxial loading stress correspond to the inflection point of self-potential. The self-potential of red sandstone varies in a range of 0–45.6 mV in that case and it fluctuates most significantly around the maximum loading point, with a range of 0.3–195.5 mV. In the end stage of loading, the macroscopic rupture of the red sandstone sample is complete, the self-potential of red sandstone fluctuates slightly around the maximum load point and then gradually stabilizes. Moreover, it is found that self-potentials change more significantly in the radial direction than in the axial direction in the uniaxial compression experiment, indicating that self-potentials generated by rock mass rupture are more sensitive in the radial direction. The rupture process of red sandstone can be dynamically represented by the tempo-spatial evolution profiles of self-potential.

Research of Inclination Angle Effect on Joint Rock Macromechanical Parameters

2011 ◽  
Vol 704-705 ◽  
pp. 1089-1094
Author(s):  
Yan Feng Feng ◽  
Tian Hong Yang ◽  
Hua Wei ◽  
Hua Guo Gao ◽  
Zhe Zhang
Keyword(s):  
Rock Mass ◽  
Uniaxial Compression ◽  
Inclination Angle ◽  
Damage Mechanics ◽  
Deformation Modulus ◽  
Strain Curve ◽  
Uniaxial Compression Test ◽  
Joint Rock Mass ◽  
Test Result ◽  
Joint Rock

The joint of rock mass influences and controls the rock mass intensity, deformation characteristics and instability failure in the rock engineering to a great extent. Using the similar material simulation is of different inclination angle of non-penetration jointing and non-jointing rock mass, through using rigid servo compression machine to carry uniaxial compression test, we get a nearly same trend of joint rock mass stress-strain curve of different angle, the curve of inclination angle of 45 is analyzed, the test result shows that the compressive strength first decreases and then increases gradually with the increase of rock inclination angle. The compression intensity is its minimum when of the inclination angle of 45°, and the deformation modulus first decreases and then increases, but deformation modulus of 30° is its minimum. In addition, through the use of developed RFPA2D system to simulate on trial uniaxial compression value based on microscopic damage mechanics, we get the conclusion that the numerical analysis and test result is fitting approximately, it is validated that the numerical model can simulate joint rock well. Keywords: joint rock mass, inclination angle, uniaxial compression, compressive intensity, deformation modulus

scholarly journals Study on Strain Characterization and Failure Location of Rock Fracture Process Using Distributed Optical Fiber under Uniaxial Compression

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3853
Author(s):  
Shiang Xu ◽  
Shuangming Wang ◽  
Pingsong Zhang ◽  
Duoxing Yang ◽  
Binyang Sun
Keyword(s):  
Rock Mass ◽  
Optical Fiber ◽  
Uniaxial Compression ◽  
Circumferential Strain ◽  
Rock Fracture ◽  
Test System ◽  
Dynamic Strain ◽  
Strain Response ◽  
Strain Characterization ◽  
Distributed Optical Fiber

A rock fracture test is a very important method in the study of rock mechanics. Based on the Mechanics Test System (MTS), the dynamic strain response of the failure process of cylindrical granite specimens under uniaxial compression was observed by using distributed optical fiber strain sensors. Two groups of tests were designed and studied for rock sample fracturing. The main comparison and analysis were made between the distributed optical fiber testing technology and the MTS testing system in terms of the circumferential strain response curve and the evolution characteristics of strain with time. The strain characterization of distributed optical fiber in the process of rock fracturing was obtained. The results show that the ring strains measured by the distributed optical fiber sensor and the circumferential strain gauge were consistent, with a minimum ring strain error of 1.27%. The relationship between the strain jump or gradient band of the distributed optical fiber and the crack space on the sample surface is clear, which can reasonably determine the time of crack initiation and propagation, point out the location of the rock failure area, and provide precursory information about rock fracture. The distributed optical fiber strain sensor can realize the linear and continuous measurement of rock mass deformation, which can provide some reference for the study of macro damage evolution and the fracture instability prediction of field engineering rock mass.

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