scholarly journals Study and Application of Similar Material Ratio in Collapsible Loess

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Bingchao Zhao ◽  
Yunxiang Ma ◽  
Yaxin Guo ◽  
Hao Sun ◽  
Jingbin Wang ◽  
...  
Keyword(s):  
Internal Friction ◽  
Moisture Content ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Similar Material ◽  
Range Analysis ◽  
River Sand ◽  
Collapsible Loess ◽  
Seam Mining ◽  
Similar Simulation

The similar material of collapsible loess is the basis and premise of the experimental study on the surface movement and deformation law of coal seam mining in collapsible loess-covered areas. The orthogonal experiment is used to make up similar material with different proportions using river sand and barite powder as aggregate, clay and gypsum as cementing material, and diatomite as adjusting material. The reasonable proportion of similar material in collapsible loess is studied by using range analysis, similar simulation, and field measurement. The results show that the content of diatomite plays a leading role in the collapsibility coefficient of similar material, and the collapsibility coefficient is positively correlated with the content of diatomite; moisture content is the main control of the cohesion of the material, and cohesion is negatively correlated with the moisture content; the ratio of bone-to-glue has the most significant effect on the internal friction angle, and the internal friction angle is positively correlated with the ratio of bone-to-glue. The reasonable ratio of the similar material in collapsible loess is 8 : 2 of the ratio of bone-to-glue, the ratio of clay-to-gypsum is 9 : 1, the barite powder content is 6%, the diatomite content is 23%, and the moisture content is 13%, and the mechanical parameters of the collapsible loess are 5.3%–6.3% different from the target value of similar material through laboratory tests, which can meet the experimental requirements. It is verified by a similar simulation experiment that the maximum surface subsidence value and the surface fracture width in the simulation results are 6.9% and 7.8% different from the field measured results, indicating a high degree of agreement. The results of the study have important references and guiding significance for the preparation of similar material with similar models.

Characterization of Shear Strength and Interface Friction of Organic Soil

2020 ◽  
Vol 857 ◽  
pp. 203-211
Author(s):  
Majid Hamed ◽  
Waleed S. Sidik ◽  
Hanifi Canakci ◽  
Fatih Celik ◽  
Romel N. Georgees
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Internal Friction ◽  
Moisture Content ◽  
Water Content ◽  
Friction Angle ◽  
Structural Materials ◽  
Organic Soil ◽  
Internal Friction Angle ◽  
Interface Friction

This study was undertaken to investigate some specific problems that limit a safe design and construction of structures on problematic soils. An experimental study was carried out to examine the influence of loading rate and moisture content on shear strength of organic soil. Influece of moisture content on interface friction between organic soil and structural materials was also attempted. A commonly used soil in Iraq was prepared at varying moisture contents of 39%, 57% and 75%. The experimental results showed that the increase in water content will decrease the shear stress and the internal friction angle. An increase of the shearing rate was found to decrease the shear stress and internal friction angle for all percetanges of water contents. Further, direct shear tests were carried out to detect the interface shear stress behavior between organic soil and structural materials. The results revealed that the increase in water content was shown to have significant negetavie effects on the interface internal friction and angle shear strength.

scholarly journals The influence of organic polymer on properties of mineral concentrates

2013 ◽  
Vol 20 (2) ◽  
pp. 90-93
Author(s):  
Marzenna Popek
Keyword(s):  
High Risk ◽  
Internal Friction ◽  
Moisture Content ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Organic Polymer ◽  
Biodegradable Materials

AbstractTransport of mineral concentrates is associated with high risk of liquefaction of the cargoes. This type of goods containing water may liquefy and shift dangerously across the cargo compartments. Therefore, it is rational to limit the moisture content of the cargoes which may liquefy. To prevent sliding and shifting of ore concentrates in storage biodegradable materials composed of starch are added to the mineral concentrates. The influence of adding starch materials to the mineral concentrates on its parameters determining ability for safe shipment was assessed on the basis of determination of the following parameters: permeability, cohesion and internal friction angle of concentrates.

scholarly journals Experimental Study on the Effect of Freezing and Thawing on the Shear Strength of the Frozen Soil in Qinghai-Tibet Railway Embankment

2022 ◽  
Vol 2022 ◽  
pp. 1-12
Author(s):  
B. Wang ◽  
J. H. Gao ◽  
Y. Q. Wang ◽  
X. J. Quan ◽  
Y. W. Gong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Internal Friction ◽  
Moisture Content ◽  
Initial Moisture Content ◽  
Friction Angle ◽  
Frozen Soil ◽  
Internal Friction Angle ◽  
Freezing Process ◽  
Dry Density ◽  
Freezing And Thawing

The direct shear tests of different dry density and moisture content samples at different temperatures of the frozen soil in the Qinghai-Tibet Railway embankment between Tanggula South and Anduo section were carried out to analyze the influence rules of each experimental factor on the mechanical properties of frozen soil during the freeze-thaw process. The results show the following. (1) When the frozen soil temperature is below 0°C and continues to drop during the freezing and thawing process, each sample shows the law of a significant increase in cohesion and a slight decrease in the internal friction angle. In the meantime, the cohesion obtained during the thawing process of the sample at the same temperature point is higher than that obtained during the freezing process. In contrast, the internal friction angles exhibit an opposite law, where the internal friction angle during the melting process is lower than the internal friction angle during the freezing process. After freezing-thawing action, it deserves to be mentioned that the cohesion increases slightly while the internal friction angles present a slight decrease trend compared to the initial state. (2) With the decrease in temperature and the gradual increase in cohesion, the temperature curve can be divided into a fast-growing section from 0 to −2°C, a slow-growing section from −2 to −8°C, and a second fast-growing section from −8 to −10°C owing to the combined effect of the pressure-thawing action and ice-water phase change. In addition, the rate of decrease in the internal friction angle also shows a similar pattern. (3) The cohesion and the internal friction angle of samples both tend to increase first and then decrease with the rise of the initial moisture content, and the critical initial moisture content is near the optimal moisture content of 15%. (4) Both the cohesion and the internal friction angle of the samples increase with dry density growth. The growth rate of cohesion will gradually increase as the temperature decreases. Moreover, the growth rate of cohesion of low dry density samples is more susceptible to temperature, while the internal friction angle growth rate is not affected by temperature.

The Sensitivity Analysis of Stability Factors of Rocky Slope with Ecological Restoration

2011 ◽  
Vol 361-363 ◽  
pp. 2003-2007
Author(s):  
Xian Yang Cai ◽  
Wen Nian Xu ◽  
Zhen Yao Xia ◽  
Zheng Jun Zhou
Keyword(s):  
Internal Friction ◽  
Ecological Restoration ◽  
Slope Angle ◽  
Base Material ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Sensitivity Factor ◽  
Range Analysis ◽  
Rocky Slope ◽  
Analysis Of Stability

Based on orthogonal experiment, the thickness of protection habitat base material (PHBM), the cohesion of PHBM, the internal friction angle of PHBM, the slope height, the slope angle and the density of PHBM are selected as influencing factors of stability of rocky slope with ecological restoration (RSER) and each factor is considered three levels. Then, using strength reduction FEM by the software ANSYS, the safety factor of RSER in various combinations is analyzed. Finally, the range analysis and comprehensive assessment are applied to the assessment of results. It is showed that the cohesion of PHBM is the dominant sensitivity factor which affects the stability of RSER, flowing by the slope height, the slope angle, the thickness of PHBM, the internal friction angle of PHBM, the density of PHBM.

scholarly journals Theoretical Analysis of Mining Induced Overburden Subsidence Boundary with the Horizontal Coal Seam Mining

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Weitao Yan ◽  
Junjie Chen ◽  
Yi Tan ◽  
Wenzhi Zhang ◽  
Lailiang Cai
Keyword(s):  
Theoretical Analysis ◽  
Internal Friction ◽  
Coal Seam ◽  
Underground Mining ◽  
Random Medium ◽  
Boundary Curve ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Horizontal Line ◽  
Seam Mining

The overburden subsidence induced by underground mining has caused great damage to the ecological environmental and seriously threatens the safe use of underground structures. Focusing on the overburden subsidence, this paper uses theoretical analysis method to study the overburden subsidence boundary with a horizontal coal seam mining. In this paper, the viscoelastic theory and the random medium theory are used separately to deduce and analyze the subsidence boundary of bedrock and unconsolidated stratum, which are two media with different lithology. For bedrock, the results show that the subsidence boundary of bedrock is 1/4 of the wavelength of pressure wave from the mining boundary, strata subsidence boundary expands with the increase of vertical distance between calculated strata and coal seam, and the subsidence boundary in bedrock is an upward concave curve. For unconsolidated stratum, the results show that the larger the internal friction angle, the greater the angle between subsidence boundary and horizontal line. From the bottom to the surface of the unconsolidated stratum, the internal friction angle decreases gradually and the angle between subsidence boundary and horizontal line also decreases gradually, so the subsidence boundary curve in the unconsolidated stratum is convex. Combined with the bedrock and unconsolidated stratum, it is concluded that the subsidence boundary of the whole overburden is bowl-shaped. This study is helpful to reveal the black box of rock subsidence and can provide theoretical support for the establishment of overburden subsidence prediction model and transparent mine in the later stage.

Experimental Study on Shear Strength of West Sichuan Unsaturated Mixed-Soil

2013 ◽  
Vol 353-356 ◽  
pp. 772-778 ◽  
Author(s):  
Kai Cui ◽  
Bang Wen Huang
Keyword(s):  
Internal Friction ◽  
Moisture Content ◽  
Water Content ◽  
Mineral Water ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Cohesive Force ◽  
Dry Density ◽  
Control Matrix ◽  
Matrix Suction

By controlling moisture content to control matrix suction indirectly, three typical unsaturated remolded mixed-soil from west Sichuan are studied by the consolidated untrained triaxial shear test .The test data show that for different kinds of soil samples, the sample with less amount of clay and high content of quartz has bigger internal friction angle relatively, and the sample with hydrophilic mineral and high content of clay has bigger cohesive force. Meanwhile, for the sample without or less hydrophilic mineral, cohesive force is affected mainly by water content, and for the sample with large content of hydrophilic mineral, water content and dry density affect cohesive force together. For a certain sample, the variation of moisture content and dry density affects internal friction angle less, while affects cohesive force more. In addition, the change of internal friction angle resulting from the variation of matrix suction is less, and cohesive force increases as matrix suction increases.

Determine the Shear Strength of Aeolian Sand and Bearing Capacity

2014 ◽  
Vol 580-583 ◽  
pp. 165-168
Author(s):  
Ying Zi Yin ◽  
Ya Lei Wang
Keyword(s):  
Internal Friction ◽  
Moisture Content ◽  
Bearing Capacity ◽  
Retaining Wall ◽  
Friction Angle ◽  
Optimum Moisture Content ◽  
Internal Friction Angle ◽  
Dry Density ◽  
Filling Material ◽  
Aeolian Sand

In this article, through aeolian sand sample study in Inner Mongolia Baotou area, to determine the aeolian sand maximum dry density and optimum moisture content. On this basis, the aeolian sand cohesion and internal friction angle were measured by the quick direct shear test when aeolian sand was at the optimum moisture content and near the most largest compactness. And the bearing capacity of retaining wall model which regarded aeolian sand as fillers was determined. Then bearing capacity change of aeolian sand wrapped before and after was compared. Experimental results showed that: when the aeolian sand was in the wet and compacted state, its cohesion was 3.31 kPa and internal friction angle was 36.8°. The aeolian sand bearing capacity was 153.8kPa by the plate loading test. The aeolian sand wrapped with a geotextile bearing capacity was 194.1kPa. Through the aeolian sand research of Baotou area, it provides a useful reference for the construction of highway and railway and application of wrap-reinforced retaining wall which is a new retaining structure in the region, and the aeolian sand is treated as a special filling material in these structures.  

Active Limit Equilibrium Method of the Stability Analysis for Soil Slopes

2012 ◽  
Vol 594-597 ◽  
pp. 636-641
Author(s):  
Ying Huang ◽  
Zu Lian Zhang ◽  
Ke Sheng Jin
Keyword(s):  
Internal Friction ◽  
Moisture Content ◽  
Limit Equilibrium ◽  
Earth Pressure ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Critical Moisture Content ◽  
Soil Slopes ◽  
Critical Moisture ◽  
The Relationship

The stability of the soil slopes can be judged according to the critical moisture content and the actual moisture content when the soil slopes be in the limit equilibrium state. From the perspective of earth pressure, the critical moisture content is the moisture content when the soil slopes be in the active limit equilibrium state, at this time, the active earth pressure is 0. The critical moisture content can be determined and the stability of the slopes can be judged according to the relationship of the soil parameters and the moisture content and the active earth pressure being 0. The critical moisture content of the upright or declining cohesionless slopes can be determined according to the relationship of the internal friction angle and the moisture content. The critical moisture content of the upright cohesive slopes can be determined by solving the equation of the critical moisture content. For the declining cohesive slopes, first, the cohesive soil having the cohesion and internal friction angle is replaced by only having the equivalent internal friction angle of the cohesionless soil according to the principle of the equal strength, then, the critical moisture content can be determined according to the relationship of the equivalent internal friction angle and the moisture content of the declining cohesionless.

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