scholarly journals GEOLOGICAL CONTROLS ON INTACT ROCK STRENGTH. THE EFFECT OF ANISOTROPY

2004 ◽  
Vol 36 (4) ◽  
pp. 1826
Author(s):  
χ. Σαρόγλου ◽  
Π. Μαρίνος ◽  
Γ. Τσιαμπάος
Keyword(s):  
Mechanical Properties ◽  
Rock Strength ◽  
Dynamic Properties ◽  
Intact Rock ◽  
Metamorphic Rocks ◽  
Deformation Characteristics ◽  
Strength Anisotropy ◽  
Ongoing Research ◽  
Strength And Deformation ◽  
Anisotropic Rocks

The factors that influence the strength and deformation of the intact rock are the mineral composition, the fabric, the grain size and the degree of alteration and weathering. Anisotropy is a characteristic of intact foliated metamorphic rocks (slates, gneisses, phyllites, schists). The current paper deals with the pronounced effect of the fabric of anisotropic rocks on the strength and deformation characteristics of intact rocks. It is part of ongoing research in the Department of Geotechnical Engineering, National Technical University of Athens. Testing was used to establish the anisotropic behaviour of selected metamorphic rocks. The effect of anisotropy on various mechanical properties (strength, deformation) and dynamic properties (wave velocity) was examined. The degree of strength anisotropy of these rocks can be indirectly estimated, by wave propagation through the rock, and thus they can be classified by means of geological and geotechnical indexes.

scholarly journals Improving the properties of composite materials for civil engineering

2019 ◽  
Vol 91 ◽  
pp. 02015
Author(s):  
Valentina Soloviova ◽  
Irina Stepanova ◽  
Nicholas Ershikov ◽  
Dmitry Soloviov
Keyword(s):  
Mechanical Properties ◽  
Chemical Activation ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Deformation Characteristics ◽  
Energy Effect ◽  
Composite Mixture ◽  
Strength And Deformation ◽  
New Generation ◽  
Hardening System

It is shown that a highly-efficient chemical activation of the cement-containing composite mixture with the help of a new generation nanostructural additive makes it possible to develop high-strength finegrained and heavy-weight concretes with the improved strength and deformation characteristics. The recommended nanostructural additive has an increased triple effect: reactive, catalytic, and plasticizing. The use of the proposed additive many times increases the hydration activity of the hardening system, exerting a double energy effect on it, chemical and thermal, thus making it possible to develop the composite building material of a new level of physical and mechanical properties.

scholarly journals Rock Strength Anisotropy in High Stress Conditions: A Case Study for Application to Shaft Stability Assessments

2015 ◽  
Vol 37 (1) ◽  
pp. 115-125 ◽  
Author(s):  
Julian Matthew Watson ◽  
Abouzar Vakili ◽  
Mateusz Jakubowski
Keyword(s):  
Rock Strength ◽  
Underground Mining ◽  
Failure Mechanisms ◽  
High Stress ◽  
Strength Anisotropy ◽  
Anisotropic Rock ◽  
Geotechnical Design ◽  
Anisotropic Rocks ◽  
Stress Environment

Abstract Although rock strength anisotropy is a well-known phenomenon in rock mechanics, its impact on geotechnical design is often ignored or underestimated. This paper explores the concept of anisotropy in a high stress environment using an improved unified constitutive model (IUCM), which can account for more complex failure mechanisms. The IUCM is used to better understand the typical responses of anisotropic rocks to underground mining. This study applies the IUCM to a proposed rock shaft located in high stress/anisotropic conditions. Results suggest that the effect of rock strength anisotropy must be taken into consideration when assessing the rock mass response to mining in high stress and anisotropic rock conditions.

STUDY OF THE INFLUENCE OF MOLECULAR MASS OF EPOXY OLIGOMERS AND HARDENERS ON THE OPERATIONAL PROPERTIES OF PAINT COATINGS

2021 ◽  
pp. 71-79
Author(s):  
V.A. Kuznetsova ◽  
◽  
S.A. Marchenko ◽  
V.V. Emelyanov ◽  
V.G. Zheleznyak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Resistance ◽  
Heat Resistance ◽  
Molecular Mass ◽  
Erosion Resistance ◽  
Physical And Mechanical Properties ◽  
Deformation Characteristics ◽  
Epoxy Oligomers ◽  
Strength And Deformation ◽  
Paint Coatings

The paper provides the results of studies of lacquer coatings made on the basis of epoxy oligomers of different molecular mass hardened by the amine type hardeners. Thermal resistance, erosion resistance, strength and deformation characteristics of free lacquer films, as well as their physical and mechanical properties have been examined. It has been determined that the properties of epoxy lacquer coatings are significantly influenced by the molecular mass of the oligomer and hardener used to produce these coatings. It is shown that with the increase in the molecular mass used to obtain coatings epoxy oligomers improve their operational properties, such as heat resistance, erosion resistance, physical and mechanical properties.

Integration of Chemofacies and Rock Mechanical Properties Using Machine Learning Algorithms: Implications for Geomechanics and Hydraulic Fracture Stimulations in Paleozoic Formations, Saudi Arabia

2021 ◽  
Author(s):  
Maaruf Hussain ◽  
Abduljamiu Amao ◽  
Khalid Al-Ramadan ◽  
Sunday Olatunji ◽  
Ardiansyah Negara
Keyword(s):  
Machine Learning ◽  
Mechanical Properties ◽  
Saudi Arabia ◽  
Spatial Distribution ◽  
Chemical Composition ◽  
Rock Strength ◽  
Machine Learning Algorithms ◽  
Unconventional Reservoirs ◽  
Geochemical Properties ◽  
Rock Mechanical Properties

Abstract The knowledge of rock mechanical properties is critical to reducing drilling risk and maximizing well and reservoir productivity. Rock chemical composition, their spatial distribution, and porosity significantly influenced these properties. However, low porosity characterized unconventional reservoirs as such, geochemical properties considerably control their mechanical behavior. In this study, we used chemostratigraphy as a correlation tool to separate strata in highly homogenous formations where other traditional stratigraphic methods failed. In addition, we integrated the chemofacies output and reduced Young's modulus to outline predictable associations between facies and mechanical properties. Thus, providing better understanding of lithofacies-controlled changes in rock strength that are useful inputs for geomechanical models and completions stimulations.

scholarly journals Effect of Grain Refinement on the Dynamic, Mechanical Properties, and Corrosion Behaviour of Al-Mg Alloy

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1825
Author(s):  
Haitham M. Ahmed ◽  
Hussin A. M. Ahmed ◽  
Mohammed Hefni ◽  
Essam B. Moustafa
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Corrosion Behaviour ◽  
Cast Alloy ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Xrd Analysis ◽  
Optical Microscope ◽  
Mg Alloy ◽  
Resonance Frequencies

In this investigation, aluminium Al-2.5% Mg cast alloy was modified by adding 0.5 Ti and 0.1 B wt % modifiers to investigate their impact on the dynamic behaviour, as well as the mechanical and microstructure properties. The dynamic properties were analysed experimentally using a free vibration impact test and predicted using finite element methods. This study used a high-resolution polarised optical microscope to analyse the microstructure of the studied alloys and X-ray Powder Diffraction (XRD) analysis to determine the developed phases. Microstructure and mechanical properties were mostly enhanced as a result of grain refining during solidification and through the metal segregation process. The microstructure analysis of the modified alloy showed a significant improvement in the grain refinement; hence, the grains were 10 times finer than the cast alloy. The modified Al-2.5% Mg/Ti-B alloy demonstrated reduced inter-granular corrosion (IGC) than the Al-2.5% Mg standard cast alloy. By incorporating Ti-B modifiers into the composition of the cast Al-Mg alloy, the ultimate tensile strength (UTS), strain (ε), and hardness values (HV) were increased by 30.5%, 100%, and 18.18%, respectively. The dynamic properties of the modified alloy showed an enhancement in the resonant (fn) and damping ratio (ζ) by 7% and 68%, respectively. The predicted resonance frequencies of the investigated alloys showed results close to the experimental dynamic tests.

scholarly journals Strength and Deformation Characteristics of the Neogene Siltstone, exampled from Middle Formation of Kazusa Group.

1993 ◽  
Vol 34 (5) ◽  
pp. 233-244 ◽  
Author(s):  
Takayasu HOSONO ◽  
Masayuki NAKAJIMA ◽  
Kazuhiro KOIZUMI ◽  
Nobutaka SUGITA ◽  
Shohji OGAWA
Keyword(s):  
Deformation Characteristics ◽  
Strength And Deformation
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