Experimental Study on the Mechanical Characteristics of Cracked Rockmass under Lateral Constraints

2005 ◽  
Vol 297-300 ◽  
pp. 2642-2647
Author(s):  
Li Jun Han ◽  
Yong Nian He
Keyword(s):  
Rock Mass ◽  
Numerical Experiments ◽  
Mechanical Characteristics ◽  
Deformation Characteristics ◽  
Underground Engineering ◽  
Hardening Behavior ◽  
Deep Underground ◽  
Strength And Deformation ◽  
Triaxial Experiment ◽  
Equivalent Continuum

Surrounding rocks of deep underground engineering are generally cracked, between which and support exists combined effect that can be reflected by the mechanical characteristics of cracked rock mass under lateral Constraints. In this paper, the strength and deformation characteristics of the cracked rock mass under lateral Constraints are investigated with methods of physical and numerical experiments. The results show that the rock mass behaves as equivalent continuum and tends to stable after deforming and re-fracturing, and has stress hardening behavior. These characteristics are obviously different from that of shearing slippage of rock samples at the residual stage of triaxial experiment.

scholarly journals Strain Rockbursts Simulated by Low-Strength Brittle Equivalent Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Lang Li ◽  
Mingyang Wang ◽  
Pengxian Fan ◽  
Haiming Jiang ◽  
Yihao Cheng ◽  
...  
Keyword(s):  
Rock Mass ◽  
Boundary Effect ◽  
High Stress ◽  
In Situ Stress ◽  
Underground Engineering ◽  
Initial State ◽  
Sharp Drop ◽  
Tunnel Support ◽  
Dramatic Rise ◽  
Deep Underground

This paper presents experimental study on rockbursts that occur in deep underground excavations. To begin with, the boundary conditions for excavation in deep underground engineering were analysed and elastic adaptive boundary is an effective way to minimize the boundary effect of geomechanical model test. Then, in order to simulate an elastic adaptive loading boundary, Belleville springs were used to establish this loading boundary. With the aforementioned experimental set-ups and fabrication of similarity models for test, the phenomena of strain mode rockbursts were satisfactorily reproduced in laboratory. The internal stress, strain, and convergences of the openings of the model were instrumented by subtly preembedded sensors and transducers. Test results showed that, with an initial state of high stress from both upper layers’ gravitational effects and in situ stress due to tectonic movements, the excavation brings a dramatic rise in the hoop stress and sharp drop in radial stress, which leads to the splitting failure of rock mass. Finally a rockburst occurred associated with the release of strain energy stored in highly stressed rock mass. In addition, the failure of the surrounding rock demonstrated an obvious hysteresis effect which supplies valuable guide and reference for tunnel support. Not only do these results provide a basis for further comprehensive experiments, but also the data can offer assisting aids for further theoretical study of rockbursts.

Numerical Simulation of Damage and Deformation Characteristics of Rock Mass with Transfixion Joint

2013 ◽  
Vol 405-408 ◽  
pp. 369-372
Author(s):  
Lei Wang ◽  
Jiang Yu ◽  
Jian Xin Han
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Strain Curve ◽  
Simulation Method ◽  
Joint Surface ◽  
Deformation Characteristics ◽  
Stress Strain Curve ◽  
Deformation Parameters ◽  
Strength And Deformation ◽  
Set Up

Use FLAC3D, the interface command to define joint surface, set up rock mass models with 15 °, 30 °, 60 °, etc. different dip joint, and in accordance with the laboratory test data of rock and joint surface for a variety of strength and deformation parameters setting, carries on the numerical simulation of uniaxial compression. Got failure mode, plastic zone evolution and the stress strain curve of rock mass with different dip joint, and the result compared with the actual test has a higher similarity, to prove the feasibility of the numerical simulation method.

Study of Evaluation Method in Terms of Structural Planes Mechanical Characteristics in Engineering Rock Mass

2013 ◽  
Vol 353-356 ◽  
pp. 384-387 ◽  
Author(s):  
Mu Dan Guo ◽  
Fu Sheng Zhu ◽  
Shu Hong Wang ◽  
Xi Jiang Mu
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Efficient Method ◽  
Weight Distribution ◽  
Evaluation Method ◽  
Mechanical Characteristics ◽  
Significant Issue ◽  
Analytic Hierarchy ◽  
Intensity Parameters ◽  
Hierarchy Process

Study of mechanical characteristics of structural planes has been significant issue in engineering rock mass stability analysis. The factors that affect the mechanical behavior of structural planes are so complicated that it is quite essential to take an efficient method to quantificationally analyze these factors. Based on the basic principals of analytic hierarchy process (AHP), a structural plane classification method-CSPC method is proposed. It can conduct weight distribution in terms of the complicated factors, assess the structural planes comprehensively and also forecast the planes intensity parameters semiquantitatively. The classification and forecast parameters of structural planes appropriately fit the cases in engineering. Furthermore, the method is easy to master for the engineers and the application can be of great prospect.

Assessment of destressing drilling efficiency using numerical methods: A case-study of Oktyabrsky deposit

2021 ◽  
pp. 26-31
Author(s):  
M. P. Sergunin ◽  
T. P. Darbinyan ◽  
T. S. Mushtekenov ◽  
V. V. Balandin
Keyword(s):  
Rock Mass ◽  
Theoretical Research ◽  
Labor Input ◽  
Efficiency Criterion ◽  
Strength And Deformation ◽  
Low Efficiency ◽  
Full Scale Tests ◽  
Time Required ◽  
Polar Division

Mineral mining in rockburst-hazardous conditions should involve various precautions in compliance with federal regulations and standards. One of the main methods to prevent rock bursts is destressing drilling. In this method, a yielding zone is artificially created. The strength and deformation characteristics in this zone differ from the same characteristics of enclosing rock mass, and redistribution of stresses takes place as a result. Efficiency of destressing drilling is estimated in terms of ore body S-2 in Komsomolsky Mine. The efficiency criterion is selected to be the safety factor of rock mass with and without destressing drilling. Low efficiency of destressing drilling means that this method is readily replaceable by the other techniques of lesser labor input, for example, by reduction in the rate of mining, or by seasoning of underground excavations for some time required for redistribution of stresses to take place. Based on the theoretical research and the conclusions drawn at NorNickel’s Polar Division, the full-scale tests are scheduled for the implementation in order to gradually abandon destessing drilling in rockburst-hazardous Talnakh and Oktyabrsky ore fields. The authors appreciate participation of V. P. Marysyuk from NorNickel’s Polar Division in this study.

Mechanical and thermal behaviors of ultra-high molecular weight polyethylene triaxial braids: the influence of structural parameters

2018 ◽  
Vol 89 (16) ◽  
pp. 3362-3373 ◽  
Author(s):  
Shenglei Xiao ◽  
Charles Lanceron ◽  
Peng Wang ◽  
Damien Soulat ◽  
Hang Gao
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Mechanical Characteristics ◽  
Structural Parameters ◽  
Tensile Tests ◽  
Tensile Behavior ◽  
Experimental Database ◽  
Strength And Deformation ◽  
Braiding Angle ◽  
Ultra High Molecular Weight

Recently, triaxial braids made from ultra-high molecular weight polyethylene (UHMWPE) have been recognized as one of the most popular composite reinforcements in the aerospace and defense fields. To further explore the mechanical characteristics of this material, a detailed experimental study on tensile behavior is reported in this paper. The triaxial braids show a “double-peak” phenomenon in tensile strength and deformation, caused by axial yarns and the in-plane shearing of bias yarns. The evolution of the braiding angle, measured during these tensile tests, is discussed according to the braiding parameters (initial braiding angle, number of axial yarns). Using the high conductivity properties of the UHMWPE material, the temperature caused by inter-yarn friction during tensile tests is also studied. This temperature is related to the evolution of the braiding angle. The temperature increases with the increasing number of axial yarns and decreases with increasing braiding angle. This study provides an experimental database on the influence of braiding parameters on the tensile behavior of triaxial braids.

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