scholarly journals THEORETICAL SOLUTION TO THE PROBLEM OF THE PROPAGATION OF STRESSES IN SOILS WHEN EXPOSED TO AXISYMMETRIC RADIAL EFFECTIVE STRESSES

2019 ◽  
Vol 10 (2) ◽  
pp. 51-58
Author(s):  
A. Z Khasanov ◽  
Z. A Khasanov ◽  
N. A Nabieva ◽  
J. A Khasanov
Keyword(s):  
Axisymmetric Problem ◽  
Soil Mass ◽  
Theoretical Studies ◽  
Effective Pressure ◽  
Tangential Stresses ◽  
Mathematical Expressions ◽  
Compression Region ◽  
Theory Equation ◽  
Space Conditions

The article discusses issues related to the determination of radial and tangential stresses in the well in the presence of gravitational pressure of the soil mass. The basis is the well-known theoretical solutions of the axisymmetric problem of a thick-walled pipe, namely, the Lame solution. The action of two pressures is considered: the internal pressure р 1 and the external р 2, uniformly distributed over the inner and outer surfaces of the hollow cylinder. As a result of theoretical studies, it was found that the use of the elasticity theory equation to determine radial and tangential stresses in a well with an internal effective pressure s r = р 1, leads to its slow horizontal decrease, which is not observed in practice. The authors proposed solutions that make it possible to obtain closer values of s r for soils. It was also experimentally proved that the value of the active compression region for soil wells with internal effective pressure р 1 is almost two times higher than the value obtained for stamp tests in half-space conditions. The authors obtained mathematical expressions of the strength and stability of wells from gravitational loads of soil.

Calculation of Technical Characteristics of the Technical Fleet Vessels Involved in Ensuring Safety of the Offshore Facilities of Oil and Gas Complex

2021 ◽  
pp. 7-13
Author(s):  
S.V. Matsenko ◽  
◽  
V.M. Minko ◽  
A.A. Koshelev ◽  
V.Yu. Piven ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Oil Pollution ◽  
Raw Materials ◽  
Experimental Studies ◽  
Industrial Safety ◽  
Theoretical Studies ◽  
Physical Processes ◽  
Oil Spill Response ◽  
Sea Area

Violation of industrial safety rules during the operation of offshore facilities for the production, storage and transportation of the hydrocarbon raw materials leads in the most cases to pollution of the marine environment with oil and its components. The works on localization and elimination of such pollution are carried out with the help of vessels of the technical support fleet and booms. When developing oil spill response plans at such facilities, a calculated determination of the technical characteristics of vessels and booms is required that are sufficient to carry out the planned activities. The basic design principles for determining the towing capacity of the technical fleet vessels involved in the localization and elimination of oil and oil product spills by trawling methods are given in the article. The calculation is based on theoretical studies performed by the authors of the physical processes occurring during the movement of objects of a mobile trawling order in the sea area. The results obtained during the course of theoretical studies were confirmed by the experimental studies carried out by the authors personally using the real pieces of equipment in the actual development of tasks for training spill containment by trawling. As a result, the empirical dependencies were obtained and experimentally confirmed, which can be used to calculate technical characteristics of the ships as part of the mobile orders and anchor systems as part of stationary orders intended for the localization and elimination of oil pollution. These results can be used, among other things, for the calculated substantiation of the technical characteristics of the technical fleet vessels designed to ensure safety of the offshore facilities for production, storage, and transportation of the hydrocarbon raw materials.

scholarly journals Parameters and modes of the technological process of scattered rice sowing

2021 ◽  
Vol 285 ◽  
pp. 02007
Author(s):  
Ivan Masienko ◽  
Sergey Shevchenko ◽  
Kirill Glytyan
Keyword(s):  
Technological Process ◽  
Radius Of Curvature ◽  
Theoretical Studies ◽  
Technological Operation ◽  
Design Features ◽  
Operating Modes ◽  
Seed Material

The paper presents the determination of main parameters and operating modes of scattered centrifugal devices of technical units when using them in the technology with scattered sowing when performing the technological operation of sowing rice in liquid-flexible soil. Theoretical studies of the dependence of design features of the blade of a spreading disk on the number of blades installed on it and the radius of curvature of the end bend on the height of blades are carried out. The values of the diameter of the disk of a centrifugal dispenser and parameters of blades are set, which will increase the uniformity of distribution of seed material for a given width of a gripper and reduce its consumption.

scholarly journals On the Algorithms Used to Compute the Standard Deviation of Wind Direction

2009 ◽  
Vol 48 (10) ◽  
pp. 2144-2151 ◽  
Author(s):  
Pierre S. Farrugia ◽  
James L. Borg ◽  
Alfred Micallef
Keyword(s):  
Standard Deviation ◽  
Wind Direction ◽  
Atmospheric Stability ◽  
Angular Distance ◽  
Circular Statistics ◽  
Horizontal Wind ◽  
Stability Class ◽  
Mathematical Expressions ◽  
Analytical Work

Abstract The standard deviation of wind direction is a very important quantity in meteorology because in addition to being used to determine the dry deposition rate and the atmospheric stability class, it is also employed in the determination of the rate of horizontal diffusion, which in turn determines transport and dispersion of air pollutants. However, the computation of this quantity is rendered difficult by the fact that the horizontal wind direction is a circular variable having a discontinuity at 2π radians, beyond which the wind direction starts again from zero, thus preventing angular subtraction from being a straightforward procedure. In view of such a limitation, this work is meant to provide new mathematical expressions that simplify both the computational and analytical work involved in handling the standard deviation of wind direction. This is achieved by deriving a number of Fourier series and Taylor expansions that can represent the minimum angular distance and its powers. Using these expressions, the relation between two algorithms commonly used to determine the standard deviation of wind direction is analyzed. Furthermore, given that these trigonometric expansions effectively reduce the mathematical complexity involved when dealing with circular statistics, their potential application to solve other problems is discussed.

A Rapid Method for the Determination of Principal Stresses Across Sections of Symmetry From Photoelastic Data

1938 ◽  
Vol 5 (1) ◽  
pp. A24-A28
Author(s):  
M. M. Frocht
Keyword(s):  
Free Boundary ◽  
Rapid Method ◽  
Circular Hole ◽  
Characteristic Curve ◽  
Principal Stresses ◽  
Recent Improvement ◽  
Tangential Stresses ◽  
Circular Holes ◽  
Photoelastic Data

Abstract The author discusses: (a) Mesnager’s theorem of isoclinics, (b) the characteristic curve of tangential stresses across a section of symmetry, (c) a formula for the maximum tangential stresses for the case of a central circular hole between fields of pure tension, (d) the slope of the p curve at a point corresponding to a cupic point, (e) recent improvement in the determination of free boundary stresses, and (f) formulas for the position of cupic points for two cases. A new method for the determination of the principal stresses across sections of symmetry from photoelastic data is illustrated with three examples: (1) Bars in tension or compression with central circular holes, (2) grooved beams in bending, and (3) rings or disks with circular central holes subjected to two concentrated diametral loads.

Determination of the relative stability of the two gauche and anti-configurations in the synthesis of new β-aminophosphonate esters: theoretical studies

2013 ◽  
Vol 40 (8) ◽  
pp. 2703-2719
Author(s):  
Sayyed Mostafa Habibi-Khorassani ◽  
Malek Taher Maghsoodlou ◽  
Fatemeh Ghodsi ◽  
Nurollah Hazeri ◽  
Mohammad Amin Kazemian ◽  
...  
Keyword(s):  
Relative Stability ◽  
Theoretical Studies

scholarly journals Determination of pressure in the near-ground space pile terminated and broadening of the surface

2018 ◽  
Vol 251 ◽  
pp. 04062
Author(s):  
Natalia Kupchikova
Keyword(s):  
Numerical Modeling ◽  
Circular Cross Section ◽  
Analytical Form ◽  
Soil Mass ◽  
Software Systems ◽  
Discrete Method ◽  
Building Foundation ◽  
Geological Conditions ◽  
Complex Engineering

The article deals with the problem of determining the stress state of a complex pile structure with end broadening in the form of a sphere in the soil mass in the analytical form by a discrete method. The calculation schemes for determining the stress tensor at the boundary of the pile of square and circular cross-section with expansions in the soil massif are shown. The elements of the polynomial are found by the discrete method in rectangular and spherical coordinates, which is a cumbersome complex mathematical apparatus for a modern design engineer. The stresses are determined. At present, as the analysis has shown, the solution of complex geotechnical problems of soil bases and foundations for different types of loads in numerical modeling is carried out using modern software. Numerical modeling and calculation with the help of specialized software systems allows to consider the system “building-foundation-ground foundation”, as dynamic, integrally developing. However, the interaction of the components of this system requires a theoretical justification of the resistance of foundations in the ground environment, especially in complex engineering-geological conditions.

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