Influence of Loading and Unloading Stress Paths on the Deformation and Failure Features of Jinping Marble Under True Triaxial Compression

2020 ◽  
Vol 53 (7) ◽  
pp. 3287-3301
Author(s):  
Xia-Ting Feng ◽  
Hong Xu ◽  
Chengxiang Yang ◽  
Xiwei Zhang ◽  
Yaohui Gao
Keyword(s):  
Triaxial Compression ◽  
Deformation And Failure ◽  
True Triaxial ◽  
Loading And Unloading ◽  
True Triaxial Compression ◽  
Jinping Marble

Brittle-ductile transition and failure mechanism of Jinping marble under true triaxial compression

2018 ◽  
Vol 232 ◽  
pp. 160-170 ◽  
Author(s):  
Jun Zhao ◽  
Xia-Ting Feng ◽  
Xi-Wei Zhang ◽  
Yan Zhang ◽  
Yang-Yi Zhou ◽  
...  
Keyword(s):  
Failure Mechanism ◽  
Triaxial Compression ◽  
True Triaxial ◽  
Brittle Ductile Transition ◽  
True Triaxial Compression ◽  
Jinping Marble

Effect of high differential stress and mineral properties on deformation and failure mechanism of hard rocks

2020 ◽  
Author(s):  
Xia-Ting Feng ◽  
Jun Zhao ◽  
Zhaofeng Wang ◽  
Cheng-Xiang Yang ◽  
Qiang Han ◽  
...  
Keyword(s):  
Triaxial Compression ◽  
Strain Curve ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Differential Stress ◽  
Deformation And Failure ◽  
True Triaxial ◽  
Elastic Plastic ◽  
Hard Rocks ◽  
True Triaxial Compression

In order to study the deformation and failure mechanism of hard rocks, true triaxial compression tests were conducted on four type of hard rocks to obtain the complete stress-strain curve and failure modes. Under true triaxial compression condition, the shape of the complete stress-strain curve can be divided into three types: elastic-brittle (EB), elastic-plastic-brittle (EPB), and elastic-plastic-ductile (EPD) types. According to the different post-peak deformation behaviours, the stress-strain curves of elastic-plastic-brittle (EPB) type can be subdivided into three sub-categories: post-peak instantaneous brittle (EPB-I) type, post-peak multi-stage brittle (EPB-M) type, and post-peak delayed brittle (EPB-D) type. The stress-strain curves change from EPD to EPB-D to EPB-M to EPB-I to EB with increasing differential stress (σ2-σ3). The deformation characteristics are dependent on the σ2, σ3, mineral composition and mineral texture to the rock sample. An increase in σ3 leads to an increased ductility, while an increase in σ2 leads to an increased brittleness. Moreover, rocks with regular mineral texture and low mineral hardness are more prone to ductility. When the deformation curve is transformed from EPD to EPB to EB, the tensile crack is gradually dominant, and the macroscopic failure angle is gradually steeper.

scholarly journals ISRM Suggested Method: Determining Deformation and Failure Characteristics of Rocks Subjected to True Triaxial Compression

2019 ◽  
Vol 52 (6) ◽  
pp. 2011-2020 ◽  
Author(s):  
Xia-Ting Feng ◽  
Bezalel Haimson ◽  
Xiaochun Li ◽  
Chandong Chang ◽  
Xiaodong Ma ◽  
...  
Keyword(s):  
Triaxial Compression ◽  
Suggested Method ◽  
Failure Characteristics ◽  
Deformation And Failure ◽  
True Triaxial ◽  
True Triaxial Compression

Post-peak deformation and failure behaviour of Jinping marble under true triaxial stresses

2020 ◽  
Vol 265 ◽  
pp. 105444
Author(s):  
Zhi Zheng ◽  
Xia-Ting Feng ◽  
Cheng-Xiang Yang ◽  
Xi-Wei Zhang ◽  
Shao-Jun Li ◽  
...  
Keyword(s):  
Deformation And Failure ◽  
True Triaxial ◽  
Failure Behaviour ◽  
Triaxial Stresses ◽  
Jinping Marble

EXPERIMENTAL INVESTIGATION ON MULTI-FRACTAL CHARACTERISTICS OF ACOUSTIC EMISSION OF COAL SAMPLES SUBJECTED TO TRUE TRIAXIAL LOADING–UNLOADING

Fractals ◽  
2020 ◽  
Vol 28 (05) ◽  
pp. 2050092 ◽  
Author(s):  
RAN ZHANG ◽  
JIE LIU ◽  
ZHANYOU SA ◽  
ZAIQUAN WANG ◽  
SHOUQING LU ◽  
...  
Keyword(s):  
Damage Evolution ◽  
Dynamic Changes ◽  
Deformation And Failure ◽  
True Triaxial ◽  
Coal Deformation ◽  
Coal Rock ◽  
True Triaxial Stress ◽  
Fractal Characteristics ◽  
Loading And Unloading ◽  
Precursory Information

Coal–rock dynamic disasters seriously threaten safe production in coal mines, and an effective early warning is especially important to reduce the losses caused by these disasters. The occurrence of coal–rock dynamic disasters is determined by mining-induced stress loading and unloading. Therefore, it is of great significance to analyze the precursory information of coal deformation and failure during true triaxial stress loading and unloading. In this study, the deformation and failure of coal samples subjected to true triaxial loading and unloading, including fixed axial stress and unloading confining stress (FASUCS), are experimentally investigated. Meanwhile, acoustic emission (AE) during the deformation of coal samples is monitored, and the multi-fractal characteristics of AE are analyzed. Furthermore, combined with the deformation and failure of coal samples, the precursory information of coal deformation and rupture during true triaxial stress loading and unloading is obtained. Finally, the relationship between multi-fractal characteristics and damage evolution of coal samples under FASUCS is discussed. The results show that the multi-fractal spectral widths of AE time series under the conditions of FASUCS with different initial confining stresses or unloading rates are quite different, but the dynamic changes of multi-fractal parameters [Formula: see text] and [Formula: see text] are similar. This indicates that the microscopic complexity of AE events of coal samples under different conditions of FASUCS differs, but the macroscopic generation mechanism of AE events has inherent uniformity. The dynamic changes of [Formula: see text] and [Formula: see text] can reflect the stress and damage degree of coal samples. The dynamic change process of [Formula: see text] well accords with the damage evolution process of coal samples. A gradual decrease of [Formula: see text] corresponds to a slow increase of damage, while a sharp increase of it corresponds to a rapid growth of damage. At the same time, the mutation point of damage curve at distinct stress difference levels shares the same variation trend with the [Formula: see text] mutation point. The change of [Formula: see text] can reflect the damage process of coal samples, which can be used as precursor information for predicting coal–rock rupture. The finding is of great significance for the early warning of coal–rock dynamic disasters.

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