scholarly journals Shearing Performance of Lime-Reinforced Iron Tailing Powder Based on Energy Dissipation

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ping Jiang ◽  
Lingqi Qiu ◽  
Na Li ◽  
Wei Wang ◽  
Aizhao Zhou ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Resource Utilization ◽  
Shear Failure ◽  
Back Propagation ◽  
Direct Shear ◽  
Effective Measure ◽  
Accuracy Requirement ◽  
Direct Shear Tests ◽  
Neural Network Algorithm ◽  
Shear Energy

The resource utilization of iron tailing powder is an effective measure to reduce the risk of tailing stacking. Based on the research findings on lime soil, a method for using lime to strengthen iron tailing powder was proposed. F-s curves and c and φ values of iron tailing powder with 0%, 2%, 4%, 8%, and 10% lime were obtained through direct shear tests. The back propagation (BP) neural network algorithm was used to fit the F-s curve, and the fitting equation that met the accuracy requirement was obtained. Based on the energy dissipation theory, the shear failure energy dissipation of iron tailing powder with different lime doses was achieved in the form of definite integrals under different normal stresses of 100 kPa, 200 kPa, 300 kPa, and 400 kPa, respectively. It was concluded that the addition of lime could increase the shear energy dissipation of iron tailing powder. The shear energy dissipation of iron tailing powder first increased and then decreased with the increase in lime dose. The maximum value was reached with 4% lime, and the energy dissipation increased linearly with increasing normal stress. In this study, the shear performance of lime-reinforced iron tailing powder was studied through the direct shear test combined with the energy dissipation theory, providing a theoretical basis for the resource utilization of iron tailing powder.

scholarly journals Investigation on Direct Shear and Energy Dissipation Characteristics of Iron Tailings Powder Reinforced by Polypropylene Fiber

2019 ◽  
Vol 9 (23) ◽  
pp. 5098 ◽  
Author(s):  
Jiang ◽  
Lv ◽  
Wang ◽  
Li ◽  
Wang
Keyword(s):  
Mathematical Model ◽  
Energy Dissipation ◽  
Back Propagation ◽  
Polypropylene Fiber ◽  
Interfacial Strength ◽  
Distribution Model ◽  
Direct Shear ◽  
Test Results ◽  
Effective Measure ◽  
The Mathematical Model

Resource utilization of iron tailings powder is an effective measure to reduce the dam-break risk of an iron tailings reservoir. Adding polypropylene fiber to iron tailings powder can improve its shear performance. Direct shear tests were carried out on reinforced iron tailings powder with polypropylene fiber with dosages of 0%, 0.25%, 0.5%, 0.75%, and 1%, respectively. The normal stresses during the tests were 100, 200, 300, and 400 kPa, respectively. The test results show that with the increase of polypropylene fiber dosage, the cohesive force of iron tailings powder firstly increases and then decreases gradually, and the internal friction angle firstly decreases and then increases. The back propagation (BP)neural network was used to fit the shear force (F) and shear displacement (s) of the test to obtain the F-s function relationship that satisfies the accuracy. Based on the energy dissipation theory, the direct shear energy dissipation of polypropylene-fiber-reinforced iron tailings powder was calculated. The mathematical model of energy dissipation of fiber interfacial failure was derived by the fiber distribution model. The interfacial strength parameters of polypropylene fiber were calculated based on the direct shear test data and the mathematical model of fiber interfacial energy dissipation. The test results show that the addition of polypropylene fiber from the perspective of energy dissipation can improve the shear properties of iron tailings powder.

scholarly journals Analisis Kestabilan Lereng Berdasarkan Kekuatan Geser Massa Batuan Terhadap Perubahan Kandungan Air Pada Tambang Batubara Di Area Blok Menyango

PROMINE ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 71-77
Author(s):  
Novandri Kusuma Wardana
Keyword(s):  
Shear Strength ◽  
Natural Condition ◽  
Shear Failure ◽  
Friction Angle ◽  
Direct Shear ◽  
Test Results ◽  
Shear Tests ◽  
Direct Shear Tests ◽  
Wet Condition ◽  
The Impact

Mining activities is commonly to work with the problem of stability of rock mass, then befordesaining mine’s slope should know rock shear strength parameters, such as cohesion (c) andinternal friction angle value ( . Beside those parameters, also needed to know the impact ofwater content to the rocks. The water content will effect rock’s shear strength, proof by the rockcondition which is ductile when it is dry and soft when it is wet. Based on test results was doneusing sandstone with laboratory scale of direct shear test were analyzed using mohr – coulomband patton criteria (1966). It is known that the cohesion (c) of sandstone decreased from 510,35kPa at natural condition down to 133,75 kPa at wet condition. The internal friction angle ( ) alsodecreased from 54,56° at natural condition down to 48,45° at wet condition. The reduction of theshear strength is caused by fragments and clay minerals characteristics which are so reactiveand very easy to absorb water so that the cohesion of the sandstone reduce the active normalstress so that working the shear stress required to cause the shear failure becomeweaker. From the results, it is also known that the shear surface roughness had a lot ofinfluence on the shear strength the normal stresses applied on the direct shear tests werevery low under 20% of UCS.

scholarly journals Characterization of Short-Term Strength Properties of Fiber/Cement-Modified Slurry

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ping Jiang ◽  
Tianhao Mao ◽  
Na Li ◽  
Liang Jia ◽  
Fang Zhang ◽  
...  
Keyword(s):  
Cement Content ◽  
Back Propagation ◽  
Strength Properties ◽  
Term Strength ◽  
Compression Tests ◽  
Short Term ◽  
Accuracy Requirement ◽  
Strength Failure ◽  
Short Term Strength ◽  
Neural Network Algorithm

The recycling of construction waste slurry is an urgent issue that needs to be solved in urban construction. To satisfy the requirements of subgrade filling, mechanical properties of fiber/cement-modified slurry were investigated. Unconfined compression tests were conducted for 7-day-cured specimens with a cement content of 5%, 10%, 15%, 20%, 25%, and 30%, respectively. Moreover, the effects of fiber contents (0.25%, 0.5%, 0.75%, and 1%, respectively) were also investigated for the specimens with a cement content of 20%. A formula satisfying the accuracy requirement was obtained by fitting the stress-strain curves using the back propagation (BP) neural network algorithm. Five parameters, including peak strength, failure strain, initial elastic modulus, residual strength, and energy dissipation, were used to characterize the short-term strength properties of fiber/cement-modified slurry. The analysis revealed that the cement content had a dominant effect on the short-term strength properties of fiber/cement-modified slurry, while the influence of fiber content was insignificant.

Classroom Lighting Energy-Saving Control System Based on Machine Vision Technology

2018 ◽  
pp. 143-149 ◽  
Author(s):  
Ruijie CHENG
Keyword(s):  
Control System ◽  
Machine Vision ◽  
Energy Saving ◽  
Back Propagation ◽  
Back Propagation Neural Network ◽  
Lighting Control ◽  
Lighting Energy ◽  
Neural Network Algorithm ◽  
Energy Saving Control ◽  
Model Algorithm

In order to further improve the energy efficiency of classroom lighting, a classroom lighting energy saving control system based on machine vision technology is proposed. Firstly, according to the characteristics of machine vision design technology, a quantum image storage model algorithm is proposed, and the Back Propagation neural network algorithm is used to analyze the technology, and a multi­feedback model for energy­saving control of classroom lighting is constructed. Finally, the algorithm and lighting model are simulated. The test results show that the design of this paper can achieve the optimization of the classroom lighting control system, different number of signals can comprehensively control the light and dark degree of the classroom lights, reduce the waste of resources of classroom lighting, and achieve the purpose of energy saving and emission reduction. Technology is worth further popularizing in practice.

scholarly journals Sand- and Clay-Photocured-Geomembrane Interface Shear Characteristics Using Direct Shear Test

2021 ◽  
Vol 13 (15) ◽  
pp. 8201
Author(s):  
Lihua Li ◽  
Han Yan ◽  
Henglin Xiao ◽  
Wentao Li ◽  
Zhangshuai Geng
Keyword(s):  
Soil Surface ◽  
Friction Angle ◽  
Direct Shear ◽  
Tensile Crack ◽  
Shear Tests ◽  
Interface Shear ◽  
Direct Shear Tests ◽  
Carbon Black Powder ◽  
Shear Characteristics ◽  
Impermeable Layer

It is well known that geomembranes frequently and easily fail at the seams, which has been a ubiquitous problem in various applications. To avoid the failure of geomembrane at the seams, photocuring was carried out with 1~5% photoinitiator and 2% carbon black powder. This geomembrane can be sprayed and cured on the soil surface. The obtained geomembrane was then used as a barrier, separator, or reinforcement. In this study, the direct shear tests were carried out with the aim to investigate the interfacial characteristics of photocured geomembrane–clay/sand. The results show that a 2% photoinitiator has a significant effect on the impermeable layer for the photocured geomembrane–clay interface. As for the photocured geomembrane–sand interface, it is reasonable to choose a geomembrane made from a 4% photoinitiator at the boundary of the drainage layer and the impermeable layer in the landfill. In the cover system, it is reasonable to choose a 5% photoinitiator geomembrane. Moreover, as for the interface between the photocurable geomembrane and clay/sand, the friction coefficient increases initially and decreases afterward with the increase of normal stress. Furthermore, the friction angle of the interface between photocurable geomembrane and sand is larger than that of the photocurable geomembrane–clay interface. In other words, the interface between photocurable geomembrane and sand has better shear and tensile crack resistance.

scholarly journals Mechanical Properties and Micro Mechanism of Nano-Clay-Modified Soil Cement Reinforced by Recycled Sand

2021 ◽  
Vol 13 (14) ◽  
pp. 7758
Author(s):  
Biao Qian ◽  
Wenjie Yu ◽  
Beifeng Lv ◽  
Haibo Kang ◽  
Longxin Shu ◽  
...  
Keyword(s):  
Shear Strength ◽  
Void Ratio ◽  
Soil Mass ◽  
Direct Shear ◽  
Test Results ◽  
The Sustainable Development ◽  
Direct Shear Tests ◽  
Soil Cement ◽  
Nano Clay ◽  
New Material

To observe the effect of recycled sand and nano-clay on the improvement of the early strength of soil-cement (7d), 0%, 10%, 15% and 20% recycled sand were added. While maintaining a fixed moisture content of 30%, the ratios of each material are specified in terms of soil mass percentage. The shear strength of CSR (recycled sand blended soil-cement) was investigated by direct shear test and four groups of specimens (CSR-1, CSR-2, CSR-3 and CSR-4) were obtained. In addition, 8% nano-clay was added to four CSR groups to obtain the four groups of CSRN-1, CSRN-2, CSRN-3 and CSRN-4 (soil-cement mixed with recycled sand and nano-clay), which were also subjected to direct shear tests. A detailed analysis of the modification mechanism of soil-cement by recycled sand and nano-clay was carried out in combination with scanning electron microscopy (SEM) and IPP (ImagePro-Plus) software. The test results showed that: (1) CSR-3 has the highest shear strength due to the “concrete-like” effect of the incorporation of recycled sand. With the addition of 8% nano-clay, the overall shear strength of the cement was improved, with CSRN-2 having the best shear strength, thanks to the filling effect of the nano-clay and its high volcanic ash content. (2) When recycled sand and nano-clay were added to soil-cement, the improvement in shear strength was manifested in a more reasonable macroscopic internal structure distribution of soil-cement. (3) SEM test results showed that the shear strength was negatively correlated with the void ratio of its microstructure. The smaller the void ratio, the greater the shear strength. This shows that the use of reclaimed sand can improve the sustainable development of the environment, and at the same time, the new material of nano-clay has potential application value.

scholarly journals Rapid prototyping of geosynthetic interfaces: Investigation of peak strength using direct shear tests

2017 ◽  
Vol 45 (6) ◽  
pp. 674-687 ◽  
Author(s):  
Gary John Fowmes ◽  
Neil Dixon ◽  
Liwei Fu ◽  
Catalin Alexandru Zaharescu
Keyword(s):  
Rapid Prototyping ◽  
Peak Strength ◽  
Direct Shear ◽  
Shear Tests ◽  
Direct Shear Tests
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