scholarly journals Experimental Study on Low-Strength Similar-Material Proportioning and Properties for Coal Mining

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Shaojie Chen ◽  
Hailong Wang ◽  
Junwen Zhang ◽  
Huilin Xing ◽  
Huaiyuan Wang
Keyword(s):  
Elastic Modulus ◽  
Compression Strength ◽  
Sand Fly ◽  
Similar Material ◽  
Simulation Test ◽  
Cement Ratio ◽  
Binder Ratio ◽  
Similar Materials ◽  
Low Strength ◽  
Similar Material Simulation

Similar-material simulation test is an effective tool to study the practical problems in mining and civil engineering. This paper conducts an orthogonal study on low-strength similar materials comprising sand, fly ash, and plaster and analyses the sensitivity of the materials. The mechanical properties of the similar materials strongly depend on the proportioning ratio, and they can satisfy different similar-material simulation tests. The compression strength and elastic modulus of the similar material decrease as the sand-binder ratio or cement ratio increases. There are approximately linear relations between the compression strength/elastic modulus and sand-binder ratio and approximately power relations between the compression strength/elastic modulus and sand-binder ratio. Sensitivity analysis employing the range method shows that the effects of the cement ratio on the compression strength and elastic modulus are more obvious than the effects of the sand-binder ratio. Finally, one of similar materials is used in a simulation test of coal backfill mining.

scholarly journals Experimental Research and Sensitivity Analysis of Mudstone Similar Materials Based on Orthogonal Design

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Caoxuan Wen ◽  
Shanpo Jia ◽  
Xiaofei Fu ◽  
Lingdong Meng ◽  
Zhenyun Zhao
Keyword(s):  
Sensitivity Analysis ◽  
Compressive Strength ◽  
Experimental Research ◽  
Orthogonal Design ◽  
Triaxial Compression ◽  
Mass Ratio ◽  
Similar Material ◽  
River Sand ◽  
Binder Ratio ◽  
Similar Materials

Due to the strong hydration sensitivity of mudstone, drilling of deep mudstone is difficult and pricy, which results in the study on its physical and mechanical properties inseparable from similar material tests. On these bases, triaxial compression and Brazilian tensile tests of the original mudstone drilled from the caprock of the D5 aquifer structure are carried out. Then, orthogonal experiments of mudstone similar materials with river sand and barite powder as aggregate and cement and gypsum as the binder are conducted, which include 3 factors that, respectively, are mass ratio of aggregate to binder, mass ratio of cement to gypsum, and barite powder content, and each factor contains 5 levels, totalling 25 groups of 150 samples. By comparing the results of mudstone and artificial samples made of similar materials, it is obvious that artificial samples and mudstone are significantly similar in terms of density, compressive strength, elastic modulus, and compressive strength when the aggregate-binder ratio is about 4, 8, 5, and 4, respectively. Further sensitivity analysis showed that the aggregate-binder ratio played a major role in controlling the properties of artificial samples, while the sensitivity of different parameters to the cement-gypsum ratio and barite content was different. The results indicate that the selected raw materials and their proportion are feasible, which can meet similar requirements and can be a reference for similar material experimental research of target mudstone.

A Method for Subsidence Monitoring of Similar Material Simulation Test in Coal Mining

2013 ◽  
Vol 765-767 ◽  
pp. 2172-2175 ◽  
Author(s):  
Min Tao ◽  
Xin Chen ◽  
Qiu Qi Ding
Keyword(s):  
Coordinate System ◽  
Coal Mining ◽  
Measurement System ◽  
Transformation Method ◽  
Reference Points ◽  
Similar Material ◽  
Simulation Test ◽  
Deformation Stage ◽  
Basic Stage ◽  
Similar Material Simulation

To accurately monitoring the subsidence of similar material simulation test in coal mining, a static deformation measurement system is proposed based on the digital image processing and photogrammetry techniques. Firstly pastes reference points and observation points on model frame and working face respectively. Before exploitation, calculates the 3D coordinates of those artificial points, transfers the default coordinate system to user defined coordinate system using 3-2-1 transformation method, and defines this stage as basic stage. Then start mining, records enough images from different position and angle, and calculates the 3D coordinates of the deformation stage. Finally aligns the single deformation stage to the basic stage, by tracking and comparing the 3D coordinates of the homonymous points, the subsidence of observation points are obtained. One similar material simulation tests were conducted which prove good performance of the proposed measurement system.

scholarly journals Experimental Development Process of a New Cement and Gypsum-Cemented Similar Material considering the Effect of Moisture

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Qi Liu ◽  
Shaojie Chen ◽  
Shuai Wang ◽  
Jing Chai ◽  
Dingding Zhang
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Moisture Content ◽  
Uniaxial Compressive Strength ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Mass Ratio ◽  
Similar Material ◽  
Residual Moisture ◽  
Similar Materials

A new type of similar material considering water characteristics is developed through orthogonal experiments. The similar material is composed of river sand, barite powder, cement, gypsum, and water. We determine the best test development process. First, the proportion test scheme is designed based on the orthogonal test. Then, the effects of the moisture content, mass ratio of aggregate to binder and other components on the density, uniaxial compressive strength, elastic model, and Poisson’s ratio of similar materials are analyzed by range analysis. Finally, the multiple linear regression equation between the parameters and the composition of similar materials is obtained, and the optimal composition ratio is determined according to the relationship between the test’s influencing factors and the mechanical properties of similar materials. The results show that the selected raw materials and their proportioning method are feasible. The content of barite powder plays a major role in controlling the density and Poisson’s ratio of similar materials. The mass ratio of aggregate to binder is the main factor that affects the uniaxial compressive strength and elastic modulus of similar materials, while the moisture content has the second largest effect on the density, uniaxial compressive strength, elastic modulus, and Poisson’s ratio of similar materials. When the residual moisture content increased from 0 to 4%, the uniaxial compressive strength and elastic modulus of similar materials decrease by 49.5% and 53.3%, respectively, and Poisson’s ratio increases by 54.8%. Determining the residual moisture content that matches the design of similar material model tests is critical to improving the test accuracy and provides a reference to prepare similar materials with different requirements.

scholarly journals Comprehensive Experimental Study of Affecting Factors on Rectangular Roadway Stability

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Zhongcheng Qin ◽  
Bin Cao ◽  
Tan Li ◽  
Xin Yu ◽  
Guangbo Chen
Keyword(s):  
Numerical Simulation ◽  
Pressure Coefficient ◽  
Surrounding Rock ◽  
Affecting Factors ◽  
Similar Material ◽  
Simulation Test ◽  
Five Factors ◽  
Roadway Stability ◽  
The Stability ◽  
Similar Material Simulation

In this paper, two methods of orthogonal numerical simulation test and similar material simulation test are used to study the influence of five factors on the stability of rectangular roadway: roadway width, roadway height, roadway buried depth, lateral pressure coefficient of surrounding rock, and comprehensive strength of surrounding rock. The results show that five factors have influence on the stability of roadway, but the degree of influence is different. The depth of the tunnel and the coefficient of the side pressure of the surrounding rock are positively correlated with the stability of the tunnel; the comprehensive strength of the surrounding rock is negatively correlated with the stability of the tunnel, but the correlation between the width and height of the tunnel and the stability of the tunnel is not obvious. The results of orthogonal numerical simulation test and similar material simulation test verify each other. The results of the field practice of the Fucun coal mine are basically consistent with the results of the two test methods, which shows that the research results have a certain guiding effect on the field roadway support.

New Similar Material Simulation Test of Overburden Rock’s Separation

2011 ◽  
Vol 121-126 ◽  
pp. 1402-1406 ◽  
Author(s):  
Wan Peng Huang ◽  
Shi Zhong Lu ◽  
Liang Wang ◽  
Sha Huang
Keyword(s):  
New Method ◽  
Similar Material ◽  
Simulation Test ◽  
Simulation Laboratory ◽  
Temperature And Humidity ◽  
Hardening Curve ◽  
Major Factors ◽  
Similar Material Simulation

The temperature and humidity in the laboratory are major factors that affect the accuracy of the similar material simulation test. This paper introduced a new similar material simulation laboratory that can keep its temperature and humidity steady. Take the new laboratory as base, doing a test to simulate the rule of overburden rock’s separation precisely. The first step of test is measuring the simulated material’s hardening curve and regressively analyzing hardening curve function. Then doing errors correction to make the simulating result precise and deducing error-correcting formula. At last, getting the rule of a certain working face’s overburden separation using the new method of similar material simulation test.

scholarly journals Mixing Ratios and Cementing Mechanism of Similar Silty Mudstone Materials for Model Tests

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Hong-Yuan Fu ◽  
Shuang-Xing Qi ◽  
Zhen-Ning Shi ◽  
Ling Zeng
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Water Content ◽  
Uniaxial Compressive Strength ◽  
Dominant Factor ◽  
Similar Material ◽  
Silty Mudstone ◽  
Mixing Ratios ◽  
Similar Materials

The similarity model test is one of the important means to study the engineering properties of soft rock. This study aims to develop similar materials for silty mudstone, which has characteristics of low strength and water expansion, based on traditional materials including gypsum, barite powder, clay minerals, and distilled water. The orthogonal design method was used to determine the mixing ratios of the similar materials. The density, uniaxial compressive strength, tensile strength, elastic modulus, and Poisson’s ratio were selected as control indicators of the similar materials. The results show that the water content is the dominant factor for the density, tensile strength, elastic modulus, and Poisson’s ratio of the similar materials of silty mudstone, while the gypsum content is the dominant factor for the uniaxial compressive strength. The physical and mechanical properties of the similar material samples with water content of 19%, barite powder ratio of 32%, and gypsum mass of 250 g show good similarity to those of the raw silty mudstone. The water absorption and expansibility of similar materials with clay mineral ratio of 12% are consistent with those of the raw silty mudstone. The scanning electron microscopy (SEM) observation indicates that the similar material with optimal mixing ratios exhibits a similar microstructure to that of silty mudstone.

scholarly journals Optimal Proportion of Similar Materials and Rockburst Tendency of White Sandstone

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Chaoyi Ma ◽  
Zhengguo Zhu ◽  
Zhichun Fang ◽  
Zhaobin Li ◽  
Liu Liu
Keyword(s):  
Iron Powder ◽  
Quartz Sand ◽  
Orthogonal Test ◽  
Sand Particle ◽  
Test Design ◽  
Similar Material ◽  
Cement Ratio ◽  
Orthogonal Test Design ◽  
Similar Materials ◽  
Powder Content

To explore the tendency of rockburst, a similar material ratio was optimised based on white sandstone. Quartz sand, iron powder, gypsum, cement, retarder, and a water-reducing agent were used as the main materials. The orthogonal test design principle was used to determine the four-factor and four-level orthogonal test design with the quartz sand content, iron powder content, gypsum-cement ratio, and sand particle size as the influencing factors. Uniaxial compression tests and tensile tests were conducted on similar material models. The tensile strength and elastic modulus were analysed, the significance of each influencing factor was investigated, and the test results of the similar materials were fitted. The optimal ratios of the similar materials of white sandstone were found to be quartz sand content of 36%, iron powder content of 1.9%, gypsum-cement ratio of 1.8 : 1, and sand particle size of 2–4 mm. The physical and mechanical properties of the similar materials were consistent with those of white sandstone. The mechanical properties of the similar materials were compared with those of the original rock. By judging the rockburst propensity and verifying the index, it is concluded that the similar materials can effectively simulate the characteristics of white sandstone, which is an ideal similar material of rockburst, and they all show strong rockburst propensity. The rock specimens with optimal proportions were produced, and the internal energy changes and rockburst mechanisms of the model at different temperatures were discussed. The results show that the rockburst process is closely related to energy, such as thermal energy and elastic strain energy, and the rock failure process can be divided into three main stages: energy accumulation, microcrack formation and propagation, and crack penetration and bursting. It provides an experimental basis for the preparation of rockburst similar materials that are more in line with the actual situation of the project and provides a basis for discussing the energy criterion of rockburst.

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.

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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