New Type Geo-Mechanical Similar Material Experiments Research and Its Application

2006 ◽  
Vol 326-328 ◽  
pp. 1801-1804
Author(s):  
Shu Cai Li ◽  
Han Peng Wang ◽  
Qiang Yong Zhang ◽  
Yong Li
Keyword(s):  
Rock Mass ◽  
Model Test ◽  
Mechanical Model ◽  
Iron Ore ◽  
Material Research ◽  
Similar Material ◽  
Mechanics Model ◽  
New Type ◽  
Stable Performance ◽  
The Ideal

It is very important to choose a similar material which simulates rock mass correctly in geo-mechanics model test. In this paper, we introduce similar material research status and analyze the principle of selecting and compounding. According to the experiences of similar material research, we develop a new similar material (we call it iron barites sand cementation material, abbreviate IBSCM) through hundreds of compounding experiment. This similar material is made up of iron ore powder, barites powder, sand, rosin, alcohol and gypsum powder. Iron ore powder, barites powder and sand are main materials, the solution of rosin and alcohol is glue, and gypsum powder is regulator. Specimen mechanics tests show that different rock mass can be simulated by the model materials with different materials compounding. The new similar material is easy to buy and its price is cheap, and it has some advantages, such as high density, stable performance, easy dryness, and easy cutting. The new similar material can simulate a lot of rock mass, so it is an ideal similar material. At last, we apply this new type similar material to tunnel geo-mechanical model test and gain the ideal result.

Research on Similar Materials for Rheological Test of Hard Rock Mass

2017 ◽  
Vol 744 ◽  
pp. 169-173
Author(s):  
Long Yun Zhang ◽  
Shang Yang Yang
Keyword(s):  
Rock Mass ◽  
Model Test ◽  
Rheological Behavior ◽  
Mechanical Model ◽  
Mechanical Tests ◽  
Surrounding Rock ◽  
Hydropower Station ◽  
Similar Material ◽  
Geological Conditions ◽  
Deep Rock

The analog material, used in the Geo-mechanical model test that is designed to study the unloading rheological behavior and failure characteristics of rock mass, must reflect the physico-mechanical behaviors of the actual rock mass. The surrounding rock of Meng-di-gou hydropower station is in complex geological conditions. With the excavation of the rock mass, the surrounding rock gradually unloading, and the property of the near rock mass. It is necessary to carry out Geo-mechanical model test to study the rheological properties of deep rock mass under complicated geological conditions. So the similar material, comprised of iron powder, barite powder, and quartz sands bound with a solution of alcohol and colophonium, is suggested to be improvable. Firstly, through more than 300 groups of mix proportion tests, the influence of different mix proportions of the ingredients are analyzed to obtain the optimal analog materials; Secondly, more than 1200 specimens are made into size Φ50mm×100mm; Lastly, physico-mechanical tests were conducted by using the specimens to test the mechanical property of the similar material, and the basic physico-mechanical parameters are obtained from the analog material. The results indicates that the property of the similar material matches well with that of the rock mass in site, so the similar material is suitable for the Geo-mechanical model test, and it can be used to test the unloading rheological behavior of rock mass of Meng-di-gou hydropower station.

Development of New-Type Similar Materials of Geomechanics Models Test for Geotechnical Engineering

2006 ◽  
Vol 326-328 ◽  
pp. 1781-1784
Author(s):  
Qiang Yong Zhang ◽  
Wei Shen Zhu ◽  
Yong Li ◽  
X.H. Guo
Keyword(s):  
Model Test ◽  
Quartz Sand ◽  
Iron Ore ◽  
Geotechnical Engineering ◽  
High Volume ◽  
Alcohol Solution ◽  
Volume Weight ◽  
Deformation Properties ◽  
Similar Materials ◽  
New Type

Geomechanics model test can simulate the real excavation process of geotechnical engineering and the mechanics deformation properties of the rockmass prototype on the condition of meeting the similar principles. In order to conducting geomechanics model test, similar material which can meet similar mechanical properties must be used. It is only after conducting a massive mechanics experiments that a new-type similar materials called iron crystal sand is developed in this paper. This material consists of iron ore powder, blanc fix, quartz sand, gypsum powder and rosin alcohol solution which are evenly mixed in certain proportion and pressed together. The iron ore powder, blanc fix and quartz sand among them are main materials. The rosin alcohol solution is the cementing agent and gypsum powder the regulator. The material mechanics experiments show that this material has following outstanding characteristics: high volume-weight, wide variable mechanical parameters, stable performance, low price, quick drying, simple processing and innocuity. It can simulate most rockmass material from soft to hard ones and can be widely used in geomechanics model tests in fields of energy sources, transportation, water conservancy and mining.

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.

New type electron gun with electrostatic and electromagnetic lenses

1978 ◽  
Vol 36 (1) ◽  
pp. 62-63
Author(s):  
T. Ichinokawa ◽  
H. Maeda
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Optimum Condition ◽  
Bias Voltage ◽  
Electron Gun ◽  
Charge Effect ◽  
Micro Fabrication ◽  
Maximum Brightness ◽  
New Type ◽  
The Ideal

I. IntroductionThermionic electron gun with the Wehnelt grid is popularly used in the electron microscopy and electron beam micro-fabrication. It is well known that this gun could get the ideal brightness caluculated from the Lengumier and Richardson equations under the optimum condition. However, the design and ajustment to the optimum condition is not so easy. The gun has following properties with respect to the Wehnelt bias; (1) The maximum brightness is got only in the optimum bias. (2) In the larger bias than the optimum, the brightness decreases with increasing the bias voltage on account of the space charge effect. (3) In the smaller bias than the optimum, the brightness decreases with bias voltage on account of spreading of the cross over spot due to the aberrations of the electrostatic immersion lens.In the present experiment, a new type electron gun with the electrostatic and electromagnetic lens is designed, and its properties are examined experimentally.

scholarly journals Stress wave propagation in different number of fissured rock mass based on nonlinear analysis

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaoming Lou ◽  
Mingwu Sun ◽  
Jin Yu
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Confining Pressure ◽  
Displacement Discontinuity ◽  
Stress Wave Propagation ◽  
Theoretical Derivation ◽  
Mechanics Model ◽  
Fissured Rock ◽  
Deep Rock ◽  
Theoretical Accuracy

AbstractThe fissures are ubiquitous in deep rock masses, and they are prone to instability and failure under dynamic loads. In order to study the propagation attenuation of dynamic stress waves in rock mass with different number of fractures under confining pressure, nonlinear theoretical analysis, indoor model test and numerical simulation are used respectively. The theoretical derivation is based on displacement discontinuity method and nonlinear fissure mechanics model named BB model. Using ABAQUS software to establish a numerical model to verify theoretical accuracy, and indoor model tests were carried out too. The research shows that the stress attenuation coefficient decreases with the increase of the number of fissures. The numerical simulation results and experimental results are basically consistent with the theoretical values, which verifies the rationality of the propagation equation.

The Study on the Ratio of Similar Material in Landslide Model Test

2011 ◽  
Vol 261-263 ◽  
pp. 1679-1684
Author(s):  
Xiao Ling Liu ◽  
Shi Mei Wang ◽  
Yun Zhi Tan ◽  
Xin Jiang Hu ◽  
Dai Peng Zhao
Keyword(s):  
Model Test ◽  
Influence Factors ◽  
Deformation Modulus ◽  
High Strength ◽  
Similar Material ◽  
Talcum Powder ◽  
Angle Of Internal Friction ◽  
Similar Materials ◽  
Mixed Material ◽  
Landslide Model

The choice of similar materials and the design of mix proportions is a key step in landslide model test. On the basis of experiment, we conduct a research for the similar materials which may sufficing volume weight, cohesive force, angle of internal friction, deformation modulus, and the infiltration coefficient on the same time. Then we put forward two kinds of schemes: one is the mixed material of high-strength glass micro beads and talcum powder; the other is the mixed material of lead beads, river sands, rubber powder and talcum powder. By analyzing the result of mix proportions test, We concluded the regularity that similar index varies along with different content of the similar material ingredients and found the notable influence factors , which provides important reference for the components of similar materials in the landslide model test.

Model Test Study on Influences of Layered Rock Mass Dip Angle on Stability of Deep-Buried Tunnel

2011 ◽  
Vol 90-93 ◽  
pp. 2363-2371
Author(s):  
Bin Wei Xia ◽  
Ke Hu ◽  
Yi Yu Lu ◽  
Dan Li ◽  
Zu Yong Zhou
Keyword(s):  
Rock Mass ◽  
Physical Model ◽  
Model Test ◽  
Physical Models ◽  
Physical Model Test ◽  
Stress Distributions ◽  
Failure Characteristics ◽  
Layered Rock ◽  
Layered Rock Mass ◽  
Dip Angle

Physical models of layered rock mass with different dip angles are built by physical model test in accordance with the bias failure characteristics of surrounding rocks of layered rock mass in Gonghe Tunnel. Bias failure characteristics of surrounding rocks in thin-layered rock mass and influences of layered rock mass dip angle on stability of tunnel are studied. The research results show that failure characteristics of physical models generally coincide with those of surrounding rocks monitored from the tunnel site. The failure regions of surrounding rock perpendicular to the stratification planes are obviously larger than those parallel to. The stress distributions and failure characteristics in the surrounding rocks are similar to each physical model of different dip angles. The stress distributions and failure regions are all elliptic in shape, in which the major axis is in the direction perpendicular to the stratification planes while the minor axis is parallel to them. As a result, obvious bias failure of surrounding rocks has gradually formed. The physical model tests provide reliable basis for theoretical analysis on the failure mechanism of deep-buried layered rock mass.

scholarly journals Experimental Study on the Ratio of Similar Materials in Weak Surrounding Rock Based on Orthogonal Design

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Pengfei Jiao ◽  
Xiao Zhang ◽  
Xinzhi Li ◽  
Bohong Liu ◽  
Haojie Zhang
Keyword(s):  
Model Test ◽  
Orthogonal Design ◽  
Surrounding Rock ◽  
Similar Material ◽  
Geomechanical Model ◽  
Geomechanical Model Test ◽  
Geological Conditions ◽  
Key Factor ◽  
Similar Materials ◽  
Weak Surrounding Rock

In the aspect of stability analysis of tunneling engineering, geomechanical model test is an important research method. A similar material is the prerequisite for the success of geomechanical model test. In the field of major engineering applications, a variety of similar materials are prepared for different geological conditions of surrounding rock and applied in some major engineering. With the use of standard sand, fine sand, and silt clay as materials, similar materials for weak surrounding rock were developed. Based on the orthogonal design method, through the direct shear test, the range analysis and variance analysis of various factors affecting the physical and mechanical parameters of weak surrounding rock are carried out. The results show similar material can meet the requirements in weak surrounding rock. Standard sand is the key factor that influences the internal friction angle of similar materials, and silt clay is the key factor affecting the cohesion of similar materials. Similar materials can meet the elastic modulus and severe requirements of the weak surrounding rock and can be used for the weak surrounding rock engineering. The new type of similar material configuration is widely used in shallow buried tunnel entrance section and urban shallow buried excavation engineering, in addition to tunnel engineering in loess stratum, and the problems of engineering design and construction are solved through geomechanical model test.

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