Numerical simulation of 3-d failure process in heterogeneous rocks

Author(s):  
Z.Z Liang ◽  
C.A Tang ◽  
H.X Li ◽  
T Xu ◽  
Y.B Zhang
2005 ◽  
Vol 83 (31-32) ◽  
pp. 2609-2631 ◽  
Author(s):  
X.S. Tang ◽  
J.R. Zhang ◽  
C.X. Li ◽  
F.H. Xu ◽  
J. Pan

2011 ◽  
Vol 378-379 ◽  
pp. 15-18
Author(s):  
Yong Bin Zhang ◽  
Zheng Zhao Liang ◽  
Shi Bin Tang ◽  
Jing Hui Jia

In this paper, a ring shaped numerical specimen is used to studying the failure process in brittle materials. The ring specimen is subjected to a compressive diametral load and contains two angled central cracks. Numerical modeling in this study is performed. It is shown that the obtained numerical results are in a very good agreement with the experiments. Effect of the crack orientation angle on the failure modes and loading-displace responses is discussed. In the range of 0°~40°, the fracture paths are curvilinear forms starting from the tip of pre-existing cracks and grow towards the loading points. For the crack orientation angle 90°, vertical fractures will split the specimen and the horizontal cracks do not influence the fracture process.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yan-Shuang Yang ◽  
Wei Cheng ◽  
Zhan-Rong Zhang ◽  
Hao-Yuan Tian ◽  
Kai-Yue Li ◽  
...  

The energy dissipation usually occurs during rock failure, which can demonstrate the meso failure process of rock in a relatively accurate way. Based on the results of conventional triaxial compression experiments on the Jinping marble, a numerical biaxial compression model was established by PFC2D to observe the development of the micro-cracks and energy evolution during the test, and then the laws of crack propagation, energy dissipation and damage evolution were analyzed. The numerical simulation results indicate that both the crack number and the total energy dissipated during the loading process increase with confining pressures, which is basically consistent with the experiment results. Two damage variables were presented in terms of the density from other researchers’ results and energy dissipation from numerical simulation, respectively. The energy-based damage variable varies with axial strain in the shape of “S,” and approaches one more closely than that based on density at the final failure period. The research in the rock failure from the perspective of energy may further understand the mechanical behavior of rocks.


2006 ◽  
Vol 324-325 ◽  
pp. 523-526 ◽  
Author(s):  
Gang Chen ◽  
Qing Ping Zhang ◽  
Zhong Fu Chen ◽  
Si Zhong Li ◽  
Yu Ze Chen

Cylindrical shell is a kind of common used structure in engineering. Interest in the response of cylindrical shells to local impact loading has increased over the last few years. A structure always endures working load more or less. For a cylindrical shell, the working load commonly is internally pressure. In this paper, a numeral simulation of wedge block impact internally Pressured cylindrical shell was carried out. The dynamic failure process of the structure was obtained. The consistency between experimental observation and numerical simulation is satisfactory.


2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Kai Zhang ◽  
Xiaojie Yang ◽  
Xuebin Cui ◽  
Yong Wang ◽  
Zhigang Tao

Nanfen open-pit iron mine is the largest single open-pit mine in Asia. Because of the lag of the extension project, the section has slowly spread in the shape of “V,” and disasters such as landslides occur frequently. In this study, first, the NPR anchor cable monitoring, which shows supernormal mechanical characteristics and can realize the monitoring and early warning target for the whole landslide process and early warning curve of bedding rock “2016-1101 landslide” in the lower wall of Nanfen open-pit mine, was analyzed, revealing the failure process of the bedding rock landslide and the force evolution characteristics of the NPR anchor cable. Then, based on the Fish language in FLAC3D and 3DEC software, the mechanical model of the NPR anchor cable was constructed, and numerical simulation was performed on the whole process of “16-1101 landslide” induced by accumulation of old landslide body. The results of this study indicate that the stress monitoring curves and failure characteristics of the NPR anchor cables in the whole process of landslide by the two numerical simulation methods are basically consistent with the field measurement results, providing a theoretical and practical basis for the mechanistic analysis and numerical simulation of other similar slopes.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Zengwei Zhang ◽  
Fan Chen ◽  
Chao Zhang ◽  
Chao Wang ◽  
Tuo Wang ◽  
...  

A grain-based rock model was developed and applied to study mechanical characteristics and failure micromechanics in thick-walled cylinder and wellbore stability tests. The rock is represented as an assembly of tetrahedral blocks with bonded contacts. Material heterogeneity is modeled by varying the tensile strength at the block contacts. This grain-based rock model differs from previous disk/sphere particle-based rock models in its ability to represent a zero (or very low) initial porosity condition, as well as highly interlocked irregular block shapes that provide resistance to movement even after contact breakage. As a result, this model can reach higher uniaxial compressive strength to tensile strength ratios and larger friction coefficients than the disk/sphere particle-based rock model. The model captured the rock fragmentation process near the wellbore due to buckling and spalling. Thin fragments of rock similar to onion skins were produced, as observed in laboratory breakout experiments. The results suggest that this approach may be well suited to study the rock disaggregation process and other geomechanical problems in the rock excavation.


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