Design and Manufacture of a New Large-Scale Three-Dimensional Geomechanics Model Test System

2010 ◽  
Vol 97-101 ◽  
pp. 2770-2773
Author(s):  
Wei Shen Zhu ◽  
Yong Li ◽  
Min Yong ◽  
Q.B. Zhang ◽  
Shu Cai Li
Keyword(s):  
Model Test ◽  
Large Scale ◽  
Three Dimensional ◽  
Great Depth ◽  
Test System ◽  
Great Stability ◽  
Underground Caverns ◽  
Structural Frame ◽  
The Stability ◽  
Design And Manufacture

Geomechanics modeling has played important role in geotechnical engineering. In order to investigate on the stability of underground caverns at great depth, a large-scale geomechanics model test system was designed and manufactured. The system mainly consisted of a steel structural frame and a hydraulic loading control system, which can apply active loading on six sides with a true three-dimensional stress state. Newly developed combinational ball sliding walls were installed on each of the major loading surfaces, which were significantly reduced the friction due to model deformation. The system has apparent technical advantages such as high stiffness, great stability, and flexibility of assembly, and easy adjustment of its dimensions.

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 Safety Evaluation of Underground Caverns Based on Monte Carlo Method

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Qifeng Guo ◽  
Zhihong Dong ◽  
Meifeng Cai ◽  
Fenhua Ren ◽  
Jiliang Pan
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Three Dimensional ◽  
Safety Evaluation ◽  
Cumulative Distribution ◽  
Three Dimensional Model ◽  
Maximum Displacement ◽  
The Monte Carlo Method ◽  
Underground Caverns ◽  
The Stability

In order to study the influence of joint fissures and rock parameters with random characteristics on the safety of underground caverns, several parameters affecting the stability of surrounding rock of underground caverns are selected. According to the Monte Carlo method, random numbers satisfying normal distribution characteristics are established. A three-dimensional model of underground caverns with random characteristics is established by discontinuous analysis software 3DEC and excavation simulations are carried out. The maximum displacement at the numerical monitoring points of arch and floor is the safety evaluation index of the cavern. The probability distribution and cumulative distribution function of the displacement at the top arch and floor are obtained, and the safety of a project is evaluated.

Potential Flow Field Generated by Downstream Moving Bars and Propagated on a Turbine Blade at Low Reynolds Number

2011 ◽  
Author(s):  
Ve´ronique Penin ◽  
Pascale Kulisa ◽  
Franc¸ois Bario
Keyword(s):  
Boundary Layer ◽  
Large Scale ◽  
Numerical Study ◽  
Three Dimensional ◽  
Potential Effect ◽  
Navier Stokes ◽  
Turbine Cascade ◽  
Wake Interaction ◽  
Rotor Stator Interaction ◽  
The Stability

During the last few decades, the size and weight of turbo-machinery have been continuously reduced. However, by decreasing the distance between rows, rotor-stator interaction is strengthened. Two interactions now have the same magnitude: wake interaction and potential effect. Studying this effect is essential to understand rotor-stator interactions. Indeed, this phenomenon influences the whole flow, including the boundary layer of the upstream and downstream blades, ergo the stability of the flow and the efficiency of the machine. A large scale turbine cascade followed by a specially designed rotating cylinder system is used. Synchronised velocity LDA measurements on the vane profile show the flow and boundary layer behavior due to the moving bars. To help the general understanding and to corroborate our experimental results, numerical investigations are carried out with an unsteady three dimensional Navier-Stokes code. Moreover, the numerical study informs about the potential disturbance to the whole flow of the cascade.

Research on 3D Geomechanics Model Test for a Large-Scale Offspur Tunnel Project

2006 ◽  
Vol 326-328 ◽  
pp. 557-560
Author(s):  
Qiang Yong Zhang ◽  
Shu Cai Li ◽  
X.H. Guo
Keyword(s):  
Model Test ◽  
Large Scale ◽  
Similar Material ◽  
Original Design ◽  
Test Installation ◽  
Deformation Properties ◽  
Hydraulic Equipment ◽  
New Type ◽  
Design And Manufacture ◽  
Test Rack

Geomechanics model test has some distinctive advantages in simulating changing laws of stress and strain of rockmass as well as failure mechanism of surrounding rockmass of tunnel. In order to systematically study mechanics deformation properties of a large-scale offspur tunnel under excavation state, we design and manufacture a large scale 3D model test rack installation with hydraulic equipment. The test rack is 3.7 meters long, 2.2 meters wide and 4 meters high, which is the largest 3D geomechanics model test rack in present Chinese communication trades. The new-type similar material of model is a kind of cementitious composite which is mixed with iron ore powder, blanc fix, quartz sand, rosin, industrial alcohol and gypsum powder. 3D geomechanics model test for a large-scale offspur tunnel is carried out by utilizing the test installation and the similar material. The original design and construction of the offspur tunnel has been effectively optimized by results from model test.

Application of Damage Rheology Model in Study on an Underground Cavern Group

2011 ◽  
Vol 90-93 ◽  
pp. 760-763
Author(s):  
Yin Ping Qi ◽  
Lv Xiang ◽  
Wei Shen Zhu
Keyword(s):  
Large Scale ◽  
Southwest China ◽  
Back Analysis ◽  
Great Depth ◽  
Underground Cavern ◽  
In Situ Stresses ◽  
The Stability ◽  
Damage Rheology ◽  
Hydropower Stations

A great number of large-scale hydropower stations are to be constructed in southwest China. Many of them feature great depth or high in situ stresses. In this paper, a coupled damage and rheology method is adopted for stability analysis of an underground cavern group with time effect to consider the rock deformation. Meanwhile, a new method considering the crackopening displacement is used for back analysis. The stability of the surrounding rock masses is then evaluated.

scholarly journals A Large Goaf Group Treatment by means of Mine Backfill Technology

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Hanwen Jia ◽  
Baoxu Yan ◽  
Erol Yilmaz
Keyword(s):  
Group Treatment ◽  
Laser Scanning ◽  
Large Scale ◽  
Mechanical Characteristics ◽  
Three Dimensional ◽  
Stability Diagram ◽  
Surrounding Rock ◽  
Mine Backfill ◽  
Treatment Scheme ◽  
The Stability

There are few studies on the management methods of large-scale goaf groups per the specific surrounding rock mass conditions of each goaf. This paper evaluates comprehensively the stability of the multistage large-scale goaf group in a Pb-Zn mine in Inner Mongolia, China, via the modified Mathews stability diagram technique. The volume of each goaf to be backfilled was quantitatively analyzed in the combination of theoretical analysis and three-dimensional laser scanning technology. The corresponding mechanical characteristics of the filling were determined by laboratory testing while formulating the treatment scheme of the large goaf group using the backfill method. The applicability of the treatment scheme using the backfill was verified by the combination of the numerical results of the distribution of the surrounding rock failure zone and the monitored data of the surface subsidence. The research results and treatment scheme using the backfill can provide a reference for similar conditions of mines worldwide.

Large scale three-dimensional seepage analysis model test and numerical simulation research on undersea tunnel

2016 ◽  
Vol 59 ◽  
pp. 510-520 ◽  
Author(s):  
Shu-cai Li ◽  
Hong-liang Liu ◽  
Li-ping Li ◽  
Qian-qing Zhang ◽  
Kai Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Large Scale ◽  
Three Dimensional ◽  
Analysis Model ◽  
Seepage Analysis ◽  
Simulation Research

scholarly journals The Stability Principle and global weak solutions of the free surface semi-geostrophic equations in geostrophic coordinates

2019 ◽  
Vol 475 (2229) ◽  
pp. 20180787
Author(s):  
M. J. P. Cullen ◽  
T. Kuna ◽  
B. Pelloni ◽  
M. Wilkinson
Keyword(s):  
Weak Solutions ◽  
Large Scale ◽  
Optimal Transport ◽  
Three Dimensional ◽  
Mathematical Framework ◽  
Atmospheric Flows ◽  
Stability Principle ◽  
The Stability ◽  
Dimensional Domain ◽  
Upper Boundary

The semi-geostrophic equations are used widely in the modelling of large-scale atmospheric flows. In this note, we prove the global existence of weak solutions of the incompressible semi-geostrophic equations, in geostrophic coordinates, in a three-dimensional domain with a free upper boundary. The proof, based on an energy minimization argument originally inspired by the Stability Principle as studied by Cullen, Purser and others, uses optimal transport techniques as well as the analysis of Hamiltonian ODEs in spaces of probability measures as studied by Ambrosio and Gangbo. We also give a general formulation of the Stability Principle in a rigorous mathematical framework.

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