scholarly journals Technological solutions for mining of off-balance gypsum reserves in difficult geological conditions

2020 ◽  
Vol 168 ◽  
pp. 00064
Author(s):  
Serhii Skipochka ◽  
Viktor Serhiienko ◽  
Volodymyr Amelin ◽  
Oleh Sytnichenko ◽  
Thibault Faucher
Keyword(s):  
Mechanical Properties ◽  
Quantitative Assessment ◽  
Underground Mining ◽  
Physical And Mechanical Properties ◽  
Strength Characteristics ◽  
Maximum Width ◽  
Geological Conditions ◽  
Selective Mining

Mining technological solutions for underground mining of offbalance gypsum reserves in difficult mining and geological conditions were justified. An analysis of typical geological disturbances of gypsum seams is carried out using the Artemivsk deposit (Ukraine) as an example. Physical and mechanical properties of rocks in disturbed zones are determined. A quantitative assessment of strength characteristics of rocks during their moistening is carried out. The minimum permissible values of the width of the tape pillar and the power of the protective stack above the camera in the presence of a violation in the roof are calculated. The use of selective mining of the lower part of the seam by combines of the “Roadheader” type is recommended. The maximum width and height of the chamber are determined by the type of combine. The technology has been tested and realized at the gypsum mine of the Additional Liability Company “Siniat”.

scholarly journals Laboratory Study of Deformation Behaviour of Two New Reinforcing Polymeric TSLs and Their Potential Application in Deep Underground Coal Mine

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2205
Author(s):  
Han Liang ◽  
Jun Han ◽  
Chen Cao ◽  
Shuangwen Ma
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Underground Mining ◽  
Deformation Behaviour ◽  
Polymer Materials ◽  
Surface Protection ◽  
Steel Mesh ◽  
Geological Conditions ◽  
Deep Underground ◽  
Roadway Support

Thin spray-on liner (TSL) is a surface protection technology used by spraying a polymer film, which is widely used for mine airtightness and waterproofing. A reinforcing TSL can replace steel mesh, which is a new method for roadway support. This paper reviews the development of a reinforcing TSL. Considering the deterioration of geological conditions in deep underground mining and the demand for reinforcing automation, two kinds of polymeric reinforcing TSL (RPTSL) materials are developed. The mechanical characteristics of the new TSL materials are studied experimentally. Results show that the average compressive strength, tensile strength, cohesion, and internal friction angle of the two TSL materials are 52 and 32 MPa, 12 and 8 MPa, 6.2 and 17.2 MPa, and 33.6° and 25.9°, respectively. The bonding strength between the two materials and coal is greater than the tensile strength of coal itself, and the mechanical properties of the material for comparison are lower than those of both materials. Based on the TSL support mechanism, we examine the application of the two TSL materials to the mining environment and compare the mechanical properties of polymer materials and cement-based materials. The advantages of polymer materials include versatile mechanical properties, good adhesion, and high early strength. This study provides a new support material to replace steel mesh for roadway surface support, which satisfies the needs of different surface support designs under complex geological conditions, and promotes the automation of roadway support.

scholarly journals Influence of nanocellulose on the hydration process of Portland cement and concrete properties

2020 ◽  
Vol 17 (5) ◽  
pp. 155-160
Author(s):  
V. I. Khirkhasova ◽  
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Physical And Mechanical Properties ◽  
Cement Composite ◽  
High Density ◽  
Strength Characteristics ◽  
New Method ◽  
Concrete Properties ◽  
Hardening Process ◽  
Study Results

The paper deals with modification of cement composite and concrete with nanocellulose in low and high density. The author presents the study results of the influence of nanocellulose on the cement composite hardening process, as well as the physical and mechanical properties of heavy concrete. The influence of the used additive on the rheological and strength characteristics of concrete is revealed. A new method is proposed to improve the material performance.

scholarly journals Determination and quality classification of rock mass of the Diatomite mine, Algeria

2021 ◽  
Vol 1 ◽  
pp. 17-24
Author(s):  
Abdessattar LAMAMRA ◽  
◽  
Dmitriy Leonidovich NEGURITSA ◽  
Samir BEDR ◽  
Ariant A. REKA ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Underground Mining ◽  
Physical And Mechanical Properties ◽  
Friction Angle ◽  
Classification Systems ◽  
Natural Phenomenon ◽  
Underground Structures ◽  
Dilatancy Angle ◽  
Mining Work

Reserch relaevance. Most ground movements are generally due to rock instability, this natural phenomenon poses a risk to humanity. The properties of the rock mass directly influence the type of movement especially in underground structures. Research aim. Our goal is to characterize and classify the rock mass of diatomite from the sig mine using geomechanical classification systems such as the RQD and RMR in order to determine the quality of the rocks in the sig mine Western Algeria from the determination of the physical and mechanical properties. Methodology. In this article, the characterization analysis of the diatomite rock mass of the sig mine was carried out. First, determinations of the physical properties and carried out the triaxial test to determine the mechanical properties (young’s modulus, the friction angle, the dilatancy angle, the cohesion, the poisson’s ratio). Secondly to classify the deposit and give a recommendation to avoid stability problems. Research results. The results from physical and mechanical analyzes, it can be said that the nature of the rock present in the diatomite (underground mine) does not have enough resistance. Conclusion. Our study definitively proves that the rock mass of sig diatomite is of very low quality and it will be very dangerous for the underground mining work of the mine especially in places where the mineralized layer is very deep. And we suggest to replace the mining technique room and pillar currently used in the diatomite mine and put another mining method which includes roof support system to ensure the safety both of the miners and the equipment.

Fire-Retardant Plastering Mortars Based on Exfoliated Vermiculite and Volcanic Ash

2021 ◽  
Vol 1043 ◽  
pp. 133-139
Author(s):  
Tolya Khezhev ◽  
Artur Zhurtov ◽  
Alim Kazharov ◽  
Tamerlan Zrumov ◽  
Asharbek Samgurov
Keyword(s):  
Mechanical Properties ◽  
Volcanic Ash ◽  
Cement Mortar ◽  
Low Cost ◽  
Fire Retardant ◽  
Physical And Mechanical Properties ◽  
Strength Characteristics ◽  
Multifunctional Additive ◽  
Solution Density ◽  
Noticeable Increase

The research results on the development of fire-retardant composite cement mortar mixtures on exfoliated vermiculite and volcanic ash with the use of a multifunctional additive are presented D-5. Compositions of fire-retardant composite mortars, which make it possible to significantly improve the physical and mechanical properties of mortar mixtures and mortars, are proposed. Introduction of a multifunctional supplement D-5 in mortar mixtures makes it possible to improve the composite mortar mixtures properties and improve the solution characteristics. Replacement of finely dispersed fraction of exfoliated vermiculite d<0,63 mm volcanic ash by volume in mortar mixtures does not cause a noticeable increase in the solution density, while their strength characteristics increase. The developed composite mortar mixtures meet the requirements of GOST 28013–98 and have a low-cost price due to volcanic ash use.

scholarly journals Influence of various additives on properties of concrete

2020 ◽  
Vol 164 ◽  
pp. 14007
Author(s):  
Zalina Tuskaeva ◽  
Soslan Karyaev
Keyword(s):  
Mechanical Properties ◽  
Water Resistance ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Air Entrainment ◽  
Strength Characteristics ◽  
Chemical Additives ◽  
Construction Time ◽  
Design Strength ◽  
Multifunctional Additive

A comparative analysis of concrete samples without chemical additives and three concrete samples with additives was carried out The first sample contains the liquid additive, the other two contain the powder additive. The article aims at finding out the effectiveness of additives influence on the physical and mechanical properties of concrete and the basis for the application areas of modified types of concrete. By means of laboratory tests, the physical and mechanical properties of concrete mixtures are determined. To determine the strength characteristics of concrete samples, the IM-1250M testing machine was used. The tests were carried out under the same temperature and humidity conditions. According to the results of the experiments, the samples with the multifunctional additive "D-5" showed the best characteristics of concrete, and the samples with the dolomite flour additive were the cheapest. As a result of the experimental analysis, the effects of three additives on the strength characteristics of concrete and water resistance were determined. Cemplast and D-5 additives are highly effective modifiers of concrete and mortar. They can increase the strength by 20-40% at the age of 28 days at dosages of 1.6-6% with a decrease in water-cement ratio and a decrease of cement amount by 20%. Additives highly increase the workability of the mixture, air entrainment and water resistance. While using the chemical additives an early set of the concrete design strength is observed for the construction time reducing in 7 days.

Experimental Study on the Engineering Characteristics of Improved Soil

2010 ◽  
Vol 168-170 ◽  
pp. 1426-1431
Author(s):  
Zhi Qing Li ◽  
Zhen Dong Cui ◽  
Yan Ping Wang ◽  
Li Chao Wang ◽  
Duo Zhong
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Fly Ash ◽  
Physical And Mechanical Properties ◽  
Hybrid Structure ◽  
Strength Characteristics ◽  
Shanxi Province ◽  
Hydration Reaction ◽  
Test Results ◽  
Shearing Strength

According to the typical loess in Shuozhou in Shanxi province, tests involved in compaction characteristics, shearing strength characteristics and disintegration are carried out by using loess and three kinds of improved loess, namely lime and fly-ash, lime and cement, cement and fly-ash. The best improved soil method is selected. The test results indicate that the compact hybrid structure is formed by fly ash and loess. The activity of fly ash is activated as a result of the lime mixing. A series of hydration reaction prompt the intensity of modified loess. And the physical and mechanical properties of improved loess are improved noticeably.

Application of New Soil Consolidator in Road-Construction Engineering

2012 ◽  
Vol 238 ◽  
pp. 466-469
Author(s):  
Hong Zhang ◽  
Dong Liang Xun ◽  
Zhao Yang ◽  
Fu Quan Ji
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical And Mechanical Properties ◽  
Road Construction ◽  
Point Of View ◽  
Curing Time ◽  
Construction Engineering ◽  
Geological Conditions ◽  
Silt Layer

This paper contrastively analyses the consolidation instances of silt with HEC and HAS soil consolidators, also emphatically discusses the influence regularities of the compressive strength of solidified soil with the following factors: the dose of consolidators and the curing time. Meanwhile, from the point of view of experiment, this paper studies the physical and mechanical properties of solidified soil. Case study shows that HEC and HAS soil consolidators behave as well as cement and lime in road-construction engineering, and even that filling subgrade independently. Also, this paper proposes the appropriate value 6% of HEC and HAS soil consolidators for solidifying silt layer, which can be used as reference for the similar geological conditions.

scholarly journals IMPACT OF VARYING PROPERTIES OF GEOLOGICAL ENVIRONMENT ON THE FORMATION OF LOADS AT SHALLOW-LAYING UNDERGROUND STRUCTURES

2020 ◽  
pp. 13-19
Author(s):  
Natalia Zuievska ◽  
Liubov Shaidetska ◽  
Valentina Gubashova
Keyword(s):  
Urban Development ◽  
Physical And Mechanical Properties ◽  
Strength Characteristics ◽  
Soil Conditions ◽  
Joint Work ◽  
Cement Material ◽  
Future Design ◽  
Soil Cement ◽  
Jet Grouting ◽  
Geological Conditions

Purpose. The purpose of this work is to consider the prospects for the use of jet grouting in urban development. On the example of the considered engineering-geological conditions to show the possibility of wide application of soil-cement elements. Methodology. To consider the main characteristic features of jet grouting, which prevail over traditional geotechnical technologies. To show the possibility of performing soil-cement elements not only in the conditions of strengthening the soil bases, but also in the conditions of anti-filtration elements when performing the protection of ditches. To present the ranges of strength characteristics of soil-cement material for soil conditions of Ukraine. Findings. The type and physical and mechanical properties of soils in which the jet-grouted element is performed will be one of the main factors influencing the geometric size of the elements and the strength of the soil-cement material. Originality. Collected and analyzed strength characteristics of soil-cement material and the presented ranges of their numerical values will allow to use them for future design of jet-routed elements in different soil conditions of Ukraine without the available personal developed practical base. Practical implications. In the progressive rhythm of urban development, the issue of new construction in the immediate vicinity of existing buildings, or the reconstruction of those in disrepair is acute. Due to its features and advantages, the technology of jet cementation allows to solve construction problems where other geotechnologies do not have the opportunity to be applied. Low dynamic impact will allow to perform soil-cement elements at strengthening of buildings and constructions in an emergency condition, low water permeability - to use jet elements as antifiltration, both single, and in joint work with other elements of designs of protection of ditches. Numerical experimental values of the strength of the material obtained by performing jet cementation, will predict the strength characteristics of future soil-cement elements.

STUDY OF THE INFLUENCE OF STABILIZERS ON THE PROPERTIES OF CARBAMIDE FOR-MALDEHYDE BINDER AND FC PLYWOOD

2020 ◽  
Vol 10 (1) ◽  
pp. 136-143
Author(s):  
A. Fedotov ◽  
Tat'yana Vahnina ◽  
Andrey Titunin ◽  
Aleksandr Sviridov
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Strength Reduction ◽  
Cohesive Strength ◽  
Urea Formaldehyde Resin ◽  
Strength Characteristics ◽  
Formaldehyde Resin ◽  
Glycerol Mono

The problem of stabilizing the properties of the urea-formaldehyde binder during storage is relevant for both glued products and resins. Changing the performance of the resin during storage makes it difficult to apply a binder and leads to a deterioration in the physical and mechanical properties of plywood. The effect of glycerol, mono- and triethanolamine, as well as a mixture of glycerol and monoethanolamine on the nominal viscosity of the resin after 56 days of storage, has been studied. The use of glycerol and monoethanolamine (including in the complex) reduces the nominal viscosity of the resin by 13.5-24.8%. The use of triethanolamine as a stabilizer makes it possible to reduce the nominal viscosity by 35% in comparison with the index of an unstabilized oligomer. Mechanical properties of FC plywood based on the stabilized and unstabilized binder has been studied. It was found that glycerol additive (or glycerol in combination with monoethanolamine) significantly reduces strength characteristics of plywood, which makes it irrational to use these stabilizers. The addition of 0.2% triethanolamine to CFS allows a 35% reduction in the nominal viscosity of the resin, while the cohesive strength of the binder decreases by 1.5%. The result is within the framework of the dispersion of the indicator, i.e. strength reduction is negligible. The static bending strength of plywood with a stabilized triethanolamine binder is more important than that of control specimens without the addition of stabilizers. The results of the study enable to recommend the addition of triethanolamine in an amount of 0.2% by weight of urea-formaldehyde resin as a rational stabilizer

scholarly journals Effects of stabilization with cement on mechanical properties of cohesive soil – sandy-silty clay

2013 ◽  
Vol 45 (2) ◽  
pp. 193-205 ◽  
Author(s):  
Wojciech Sas ◽  
Andrzej Głuchowski
Keyword(s):  
Mechanical Properties ◽  
Ground Improvement ◽  
Physical And Mechanical Properties ◽  
Cohesive Soil ◽  
Strength Characteristics ◽  
Silty Clay ◽  
Foundation Design ◽  
Stress Strain ◽  
Clay Ground ◽  
The Relationship

Abstract Effects of stabilization with cement on mechanical properties of cohesive soil - sandy- -silty clay. Ground improvement as a result of stabilization with cement has its impact on soft soils such as sandy clay in engineering constructions. Stabilized soils are also used in foundation design, where improvement of mechanical properties is needed. Because of these reasons, knowledge of physical and mechanical properties is needed. The relationship stress - strain of soils stabilized with cement is often unclear and strength characteristics need to be clear. In this paper results of physical and mechanical properties soil stabilized with cement are presented

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