The stress-deformation state of rocks near underground workings excavated by drilling and blasting

Main goal of this article is to introduce an used methodology of analyses for excavation of surge tank enlargement of HEC MATKA1. The way of combining of the methods for analyses of discontinual and continual media are explained. The main information’s about existing geological and geotechnical properties are also given, as a basis for analytical and numerical analyses. Some of the results from the stability analyses of structural controlled instabilities during excavation of water tank are presented. The newly secondary stress – deformation state as a result from enlargement (excavation) is analysed with program Z-SOIL.

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The stress-deformation state of an elastic half-space with a spheroidal thermal inclusion

International Applied Mechanics ◽

10.1007/bf00847125 ◽

1992 ◽

Vol 28 (7) ◽

pp. 426-434

Author(s):

V. S. Kolesov ◽

N. M. Vlasov ◽

L. O. Tisovskii ◽

I. P. Shatskii

Keyword(s):

Half Space ◽

Elastic Half Space ◽

Deformation State ◽

Stress Deformation ◽

Thermal Inclusion

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Modeling of Post-Failure Behavior of the Rock Mass and its Effect on the Stress-Deformation State in the Vicinity of a Mining Excavation

Advances in Science and Technology – Research Journal ◽

10.12913/22998624/108647 ◽

2019 ◽

Vol 13 (2) ◽

pp. 130-140

Author(s):

Halina Marczak

Keyword(s):

Rock Mass ◽

Failure Behavior ◽

Deformation State ◽

Stress Deformation

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Stress-deformation state of compound reinforced concrete bars with high-strength reinforcement prone to long-term compression

Vestnik MGSU ◽

10.22227/1997-0935.2019.9.1121-1131 ◽

2019 ◽

pp. 1121-1131

Author(s):

Kristina I. Zarakovskaya ◽

Vladimir F. Zakharov

Keyword(s):

Reinforced Concrete ◽

Stress State ◽

Calculation Method ◽

High Strength ◽

Longitudinal Reinforcement ◽

Deformation State ◽

Stress Deformation ◽

Strain Stress ◽

Compound Section

Introduction. Considering that reinforced concrete is the most common material in construction and reconstruction of buildings and facilities, research of work of high-strength reinforcement in reinforced concrete elements, including compressed columns, are still relevant at present. Analysis of compound-section columns with high-strength longitudinal reinforcement is of particular interest since the method of sectional build-up is widespread enough in the reconstruction of buildings and facilities. However, no information on the work of this kind of reinforced concrete structures under long-term compression was found either in foreign or domestic literature; this fact provides relevance and academic novelty of the study. Materials and methods. The article provides the research of parameters of the strain-stress state of compound reinforced concrete bars with high-tensile reinforcement under long time compression employing the modern methods of mathematical simulation. Results. The developed calculation method allows determining additional parameters of the strain-stress state of the compressed compound-section reinforced concrete bars considering the concrete creep deformations forming in time of the long-term compression. When comparing the analytical study results with authors’ experimental data and previous results of other researchers, an adequate degree of reliability of the developed calculation method was confirmed. Conclusions. When applying the developed calculation method of stress-deformation state parameters for the compressed compound-section columns with high-strength longitudinal reinforcement, the study discovered that significant effort redistribution from concrete to high-strength reinforcement occurs under long-term compression. This fact was confirmed with the results of an experimental investigation on the resistance of the compound reinforced concrete bars with high-tensile reinforcement to the longtime compression.

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The effect of anisotropy of elastic properties of GFRP reinforcement on strength of compressed concrete structural elements

Vestnik MGSU ◽

10.22227/1997-0935.2019.6.669-679 ◽

2019 ◽

pp. 669-679

Author(s):

Mikhail G. Plyusnin ◽

Sergey V. Tsybakin

Keyword(s):

Numerical Simulation ◽

Elastic Properties ◽

Strength Reduction ◽

Fibre Glass ◽

Deformation State ◽

Stress Deformation ◽

Concrete Elements ◽

Lateral Reinforcement ◽

Gfrp Reinforcement ◽

Moduli Of Elasticity

Introduction. Despite the growing interest to the use of GFRP reinforcement in various concrete structures, its use in the concrete compressed zone is not investigated sufficiently. The use of GFRP reinforcement in compressed concrete elements is limited by a combination of low value of its modulus of elasticity and small ultimate deformation of concrete during compression. A number of researchers suggest solving this problem by means of increase the ultimate concrete deformation due to lateral reinforcement. However, unlike steel reinforcement, the elastic properties of composite reinforcement depend on the stress direction, which is due to the significant difference between the moduli of elasticity of the fibre glass and the binder. Consequently, the stress-deformation state of compressed concrete elements with longitudinal GFRP reinforcement and close-set lateral reinforcement will differ from the stress-deformation state of steel-reinforced concrete elements. Materials and methods. To clarify the effect of the anisotropy of fibre-glass reinforcement elastic properties on its work in the concrete compressed zone, a physical experiment and numerical simulation using the LIRA-SAPR software were carried out. Physical nonlinearity of materials was not taken into account in the model. Results. An assessment of the effect of anisotropy of elastic properties of fibre-glass reinforced plastic (GFRP) reinforcement on the strength of compressed concrete elements was accomplished for longitudinal reinforcement. The experiment showed that the location of the longitudinal GFRP reinforcement in the concrete compressed zone in the absence of lateral reinforcement led to a decrease in the average strength of the tested samples by 9.2 %, while the fracture nature of GFRP-reinforced samples differed from the fracture nature of control samples. As a result of the numerical simulation, it was revealed that the cause of the strength reduction is the anisotropy of the elastic properties of GFRP reinforcement, which affects the stress-deformation state of compressed concrete. Conclusions. The analysis of the results of experiment and numerical simulation showed that the reason for the decrease in strength is the low modulus of elasticity of GFRP when compressed in the lateral direction as compared with the similar characteristic of concrete. The degree of strength reduction will also depend on the relation between the moduli of elasticity of concrete and GFRP when compressed in the longitudinal direction.

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