True Three-Dimensional Geomechanical Model Tests for Stability Analysis of Surrounding Rock During the Excavation of a Deep Underground Laboratory

2019 ◽  
Vol 53 (2) ◽  
pp. 517-537 ◽  
Author(s):  
Qiangyong Zhang ◽  
Chuancheng Liu ◽  
Kang Duan ◽  
Zhenjie Zhang ◽  
Wen Xiang
Keyword(s):  
Stability Analysis ◽  
Three Dimensional ◽  
Model Tests ◽  
Surrounding Rock ◽  
Underground Laboratory ◽  
Geomechanical Model ◽  
Deep Underground

Geo-Stress Measurement and its Application in the Yangchangwan Coal Mine

2013 ◽  
Vol 353-356 ◽  
pp. 398-402
Author(s):  
Xiao Yu Zhang ◽  
Feng Ming Liu ◽  
Gang Chen
Keyword(s):  
Stability Analysis ◽  
Coal Mine ◽  
Basic Parameter ◽  
Stress Measurement ◽  
Three Dimensional ◽  
Stress Relief ◽  
Tectonic Stress ◽  
Surrounding Rock ◽  
Support Design ◽  
Rock Stability

The initial stress of rock is a basic parameter, which can be used for surrounding rock stability analysis, exploitation and support design. By utilizing stress relief method of hollow inclusion with its characters of high precision and obtaining three dimensional stress at one time, we have measured three dimensional stress magnitude and direction in north wing roadway (-850m) and 710 open-off cut (-1000m), respectively. The results show that the horizontal tectonic stress is obvious in this coal area.

Large-scale geomechanical model testing of an underground cavern group in a true three-dimensional (3-D) stress state

2010 ◽  
Vol 47 (9) ◽  
pp. 935-946 ◽  
Author(s):  
W. S. Zhu ◽  
Q. B. Zhang ◽  
H. H. Zhu ◽  
Y. Li ◽  
J.-H. Yin ◽  
...  
Keyword(s):  
Stress State ◽  
Large Scale ◽  
Three Dimensional ◽  
Great Depth ◽  
Model Tests ◽  
Geomechanical Model ◽  
Testing Procedures ◽  
Test Initiation ◽  
The Stability ◽  
Made In

The stability of a large cavern group at great depth is discussed on the basis of large-scale three-dimensional (3-D) geomechanical model tests and numerical simulations. The model tests are described in detail. Improvements in the tests were made in terms of experimental techniques and advanced measurement methods. The model tests utilized active loading on six sides of a rock mass in a true 3-D stress state. During the model construction, precast blocks were fabricated and monitoring holes were defined prior to test initiation. Newly developed combination ball-sliding walls were installed on each of the major loading surfaces to reduce the friction induced by model deformation. A unique grouting and installation technique employing prestressed cables was adopted in the tests. A digital photogrammetric technique, displacement sensing bars using fiber Bragg grating (FBG) technology, and mini multipoint extensometers were developed for measuring deformation. Overloading tests were then conducted for different overburden depths, and 3-D numerical analyses were performed to simulate the testing procedures. Conclusions regarding the stability of the cavern group were developed based on a comparison between the experimental and numerical results.

scholarly journals The Elastoplastic Solutions of Deep Buried Roadway Based on the Generalized 3D Hoek-Brown Strength Criterion considering Strain-Softening Properties

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Rui Wang ◽  
Jian-biao Bai ◽  
Shuai Yan ◽  
Zhi-guo Chang ◽  
Yuan-ba Song ◽  
...  
Keyword(s):  
Strain Softening ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Strength Criterion ◽  
Surrounding Rock ◽  
Theoretical Research ◽  
Flow Rule ◽  
Softening Behavior ◽  
Deep Underground ◽  
Elastoplastic Solutions

The deep underground roadways are widely used in the mining industries at present, but the relevant theoretical bases are not fully understood. In this paper, the numerical solutions for strain-softening surrounding rock under the generalized three-dimensional (3D) Hoek-Brown (GZZ) strength criterion are developed incorporating the confinement-dependent characteristics of ψ and η ∗ and their influences on the stress and displacement of equivalent circular roadway. On the basic of a finite difference, method for the strain-softening model is proposed to consider the variation of ψ and η ∗ in analyzing the strain-softening behavior of rock masses. Combining the equilibrium equation and strength criterion, the stress conditions for each annulus are calculated analytically. The displacement for each step is obtained analytically by solving the differential equation through invoking flow rule and Hooke’s law. The accuracy of the proposed method is verified through the comparison between the results and the previous studies. The effect of intermediate principal stress of GZZ strength criterion is considered; the rationality of the proposed method is verified by two aspects. First, by comparing with the two-dimensional narrow and generalized H-B strength criterion, the advantage of GZZ strength criterion that considers the effect intermediate main stress is highlighted. On the other hand, compared with the three-dimensional linear D-P criterion, the advantage of GZZ strength criterion in the theoretical research of deep underground roadway in coal mine is highlighted. The results show that the strain-softening of the surrounding rock in the plastic zone of the roadway can reduce the pressure of the surrounding rock, but it will greatly increase its deformation. In the high field stress areas, the strain-softening of surrounding rock is the key reason for the destruction of the roadway. It is suggested that in the design and calculation of the support system of the roadway, the strain-softening characteristics of the surrounding rock should be considered, which is very important to avoid large deformation and damage of roadway.

Numerical solutions for strain-softening surrounding rock under three-dimensional principal stress condition

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sheng Yu-ming ◽  
Li Chao ◽  
Xia Ming-yao ◽  
Zou Jin-feng
Keyword(s):  
Finite Element ◽  
Principal Stress ◽  
Stress Condition ◽  
Strain Softening ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Strength Criterion ◽  
Surrounding Rock ◽  
Flow Rule ◽  
Finite Element Software

Abstract In this study, elastoplastic model for the surrounding rock of axisymmetric circular tunnel is investigated under three-dimensional (3D) principal stress states. Novel numerical solutions for strain-softening surrounding rock were first proposed based on the modified 3D Hoek–Brown criterion and the associated flow rule. Under a 3D axisymmetric coordinate system, the distributions for stresses and displacement can be effectively determined on the basis of the redeveloped stress increment approach. The modified 3D Hoek–Brown strength criterion is also embedded into finite element software to characterize the yielding state of surrounding rock based on the modified yield surface and stress renewal algorithm. The Euler implicit constitutive integral algorithm and the consistent tangent stiffness matrix are reconstructed in terms of the 3D Hoek–Brown strength criterion. Therefore, the numerical solutions and finite element method (FEM) models for the deep buried tunnel under 3D principal stress condition are presented, so that the stability analysis of surrounding rock can be conducted in a direct and convenient way. The reliability of the proposed solutions was verified by comparison of the principal stresses obtained by the developed numerical approach and FEM model. From a practical point of view, the proposed approach can also be applied for the determination of ground response curve of the tunnel, which shows a satisfying accuracy compared with the measuring data.

scholarly journals Stability analysis and attractor dynamics of three-dimensional dark solitons with localized dissipation

2021 ◽  
Vol 103 (4) ◽  
Author(s):  
Christian Baals ◽  
Alexandre Gil Moreno ◽  
Jian Jiang ◽  
Jens Benary ◽  
Herwig Ott
Keyword(s):  
Stability Analysis ◽  
Three Dimensional ◽  
Dark Solitons ◽  
Attractor Dynamics
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