scholarly journals Development and testing of an algorithm for calculating the load on support of mine workings

2021 ◽  
Vol 15 (1) ◽  
pp. 1-10
Author(s):  
Volodymyr Bondarenko ◽  
Iryna Kovalevska ◽  
Frederick Cawood ◽  
Oleksandr Husiev ◽  
Vasyl Snihur ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Support System ◽  
Mine Working ◽  
Strain State ◽  
The Finite Element Method ◽  
Load Bearing ◽  
Geological Conditions ◽  
Mine Workings ◽  
Roof Rocks

Purpose. The purpose is to develop the calculation methods for minimizing the load on the fastening system of the preparatory mine working in difficult mining and geological conditions of its maintenance. Methods. By analysing the multivariate computational experiments on the study of the stress-strain state of the load-bearing elements of the ‘massif – support’ system in the preparatory mine workings by means of the finite-element method, as well as mine observations and measurements of displacement in the coal-overlaying rock formation. Findings. An algorithm has been developed for searching the rational modes of the fastening system resistance and methods for minimizing the load on the support of the preparatory mine working, maintained in very complex mining and geological conditions. Originality.The methodical principles have been developed of minimizing the load on the fastening system of the preparatory mine working, which are based on the use of a combination of stress-strain state studies of the ‘massif – support’ system by means of the finite element method and provisions of normative documents for calculating the dimensions of the dome of natural equilibrium of the mine working roof rocks. Practical implications. The operation modes optimisation of the load-bearing elements interaction of the mine working fastening system reduces the material and labour costs during its construction and increases its stability during operation. Keywords: analysis, calculation, optimization, support, preparatory mine working, stope works, roof rocks, collapse

scholarly journals Testing Crack Resistance of Non-Load-Bearing Ceramic Walls with Door Openings

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1379
Author(s):  
Tomasz Kania ◽  
Valery Derkach ◽  
Rafał Nowak
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Building Structure ◽  
The Finite Element Method ◽  
Short Term ◽  
Load Bearing ◽  
Door Opening ◽  
Partition Walls ◽  
Internal Partition ◽  
New Buildings

Cracking in non-load-bearing internal partition walls is a serious problem that frequently occurs in new buildings within the short term after putting them into service or even before completion of construction. Sometimes, it is so considerable that it cannot be accepted by the occupiers. The article presents tests of cracking in ceramic walls with a door opening connected in a rigid and flexible way along vertical edges. The first analyzes were conducted using the finite element method (FEM), and afterward, the measurements of deformations and stresses in walls on deflecting floors were performed on a full scale in the actual building structure. The measurements enabled to determine floor deformations leading to cracking of walls and to establish a dependency between the values of tensile stresses within the area of the door opening corners and their location along the length of walls and type of vertical connection with the structure.

Research of throwing areols of underground pipeline in permafrost

2021 ◽  
pp. 21-30
Author(s):  
T. S. Sultanmagomedov ◽  
◽  
R. N. Bakhtizin ◽  
S. M. Sultanmagomedov ◽  
T. M. Halikov ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Experimental Study ◽  
Finite Element ◽  
Strain State ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Loss Of Stability ◽  
Underground Pipeline ◽  
The Finite Element Method ◽  
Permafrost Thawing

Study is due to the possibility of loss of stability of the pipeline in the process of pumping a product with a positive operating temperature and the formation of thawing halos. The article presents the ways of solving the thermomechanical problem of pipeline displacement due to thawing. The rate of formation of a thawing halo is investigated depending on the initial temperatures of the soil and the pumped product. The developed monitoring system makes it possible to study the rate of occurrence of thawing halos in the process of pumping the product. An experimental study on the formation of thawing halos around the pipeline was carried out on an experimental model. A thermophysical comparative calculation of temperatures around the pipeline on a model by the finite element method has been carried out. Keywords: underground pipeline; permafrost; thawing halo; monitoring; operating conditions; stress–strain state.

scholarly journals Choice of technologies of ensuring exploitation suitability of buildings in the underground construction area

Vestnik MGSU ◽  
2020 ◽  
pp. 452-461
Author(s):  
Emil Imran Оglu Alirzaev ◽  
Marina E. Dement'eva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
The Finite Element Method ◽  
Underground Construction ◽  
Underground Structures ◽  
Stress Strain ◽  
Computer Complex ◽  
Stress Strain State ◽  
Element Method

Introduction. One of the serious problems in the construction of underground structures in a dense urban area is the occurrence of excess deformations of the foundations of operating buildings that fall into the zone of influence of underground construction. The subject of the study was the calculated justification of the modern technology of compensatory injection. The relevance of the task is determined by the fact that the choice of the most effective protection technology should be based not only on a comparison of technological precipitation with maximum permissible values, but also on the assessment of the possibility of monitoring and controlling the movements of the foundations of buildings and structures during construction and subsequent operation. The purpose of the study was to compare various methods of protecting the foundations of existing buildings and structures and justify the selection of the most effective of them for further implementation and dissemination in the design and construction of urban underground structures. Materials and methods. On the basis of the survey data of the operated building falling into the impact zone of excavation of the pit for the construction of the installation and shield chamber of the subway, the parameters of the stress-strain state of its foundations are studied by mathematical modeling. The problem was solved by the finite element method based on the software and computer complex Z_Soil v.18.24. Results. Based on the analysis of the results of the examination of the administrative building using the finite element method, a change in the parameters of the stress-strain state of the foundations was modeled with various technologies for strengthening it. In the course of solving the geotechnical problem, it was found that the minimum impact on the foundations of the building during the construction of the pit was obtained in the method of compensatory injection. The system of criteria for making a decision on choosing an effective way to ensure the suitability of buildings in the underground construction zone for operation is substantiated. Conclusions. The results of this work can be used to justify the choice of technology for prevention and control of excess deformations of foundations. The function for calculating the volume of injected material in the Z_Soil software and computer complex can be used to justify the consumption of materials and the economic efficiency of the technological solution.

scholarly journals Assessment of the mutual influence of deformation-strength characteristics of the fastening system elements

2019 ◽  
Vol 123 ◽  
pp. 01006 ◽  
Author(s):  
Iryna Kovalevska ◽  
Zenon Pilecki ◽  
Oleksandr Husiev ◽  
Vasyl Snihur
Keyword(s):  
Mine Working ◽  
Strain State ◽  
Mutual Influence ◽  
Strength Characteristics ◽  
Stress Strain ◽  
Load Bearing ◽  
Stress Strain State ◽  
Operation Modes ◽  
Mine Workings ◽  
Rigid Element

The degree of influence has been determined of diversified deformation-strength characteristics of load-bearing elements in the fastening system of the preparatory mine workings, while maintaining them in a laminal massif of soft rocks. The analysis has been performed of multivariate computational experiments of the stress-strain state of the load-bearing elements of the fastening system in the preparatory mine workings from the position of the mutual influence of their deformation-strength characteristics and the support loading as a whole. An analysis is represented of the mutual influence of the operation modes of the mine working support elements between themselves and the fastening system as a whole; it has been studied the stress-strain state of the mine working fastening system with a central hydraulic prop stay, as well as a significant increase in reliability of the support performance has been analysed and determined. The tendency has been substantiated of minimizing the load on the mine working fastening system – increasing the coherence of the diversified operation modes of fastening elements by enhancing preferentially the yielding property of the rigid element. The application has been substantiated of the central yielding prop stays of the strengthening support of a frame in case of intensive rock pressure manifestation in the zone of the stope works active influence.

scholarly journals Specific solution of problem of water filtering in the rocks by the finite element method

2019 ◽  
Vol 109 ◽  
pp. 00093 ◽  
Author(s):  
Olena Slashchova ◽  
Ihor Slashchov ◽  
Iryna Sapunova
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
Water Saturation ◽  
Physical And Mechanical Properties ◽  
Critical Parameters ◽  
The Finite Element Method ◽  
Water Saturated ◽  
Element Method

The article is devoted to development of methods for geofiltration calculations with taking into account peculiarities of changes of the rock physical and mechanical properties at water saturation. Methods: mathematical modeling of geomechanical and filtration processes with the help of finite element method and laboratory and underground studies. A mathematical model was formulated for solving a problem of elasticity theory by the finite element method, which took into account peculiarities of water-saturated rocks. Pattern of stress-strain state changing in the fractured water-saturated rocks under the action of critical loads, which occurred around the preparatory roadways during their operation, were established. In order to solve the filtration problems, a bank of collected initial data on physical and mechanical properties of water-saturated rocks was processed with the help of variation coefficients, which were taken into account by the method, which assumed calculation of the model loading with critical parameters.

scholarly journals The Influence of Technological Conditions of the Process of Cogging in Flat Dies on the Quality of Two-Phase Titanium Alloys

2016 ◽  
Vol 61 (2) ◽  
pp. 671-676
Author(s):  
Н. Dyja ◽  
А.А. Тukibay ◽  
S.A. Mashekov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Titanium Alloys ◽  
Quantitative Data ◽  
Strain State ◽  
Industrial Technology ◽  
The Finite Element Method ◽  
Two Phase ◽  
Optimal Values

Abstract To create a rational technology of cogging process and to determinate the optimal values of the angles of tilt and single reduction the stress-strain state (SSS) of the blank during cogging in the flat dies was analyzed. By using the finite element method and program MSC.SuperForge quantitative data are obtained and the basic patterns of distribution of SSS, the temperature during the simulation of tilting in flat dies with different angles of tilting and the amount of reduction were established. Sustainable experimental-industrial technology of forging of two-phase titanium alloys was developed and tested.

Investigation of the stress-strain state of turbine rotors by the finite-element method

1982 ◽  
Vol 14 (8) ◽  
pp. 1119-1123 ◽  
Author(s):  
P. P. Gontarovskii ◽  
L. I. Gontarovskaya ◽  
G. A. Marchenko ◽  
Yu. I. Matyukhin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Turbine Rotors ◽  
Element Method

Nonlinear Analysis Method Research of Multi-Bolt Connection Structure of Primary Equipment Support

2017 ◽  
Author(s):  
Jianrong Zou ◽  
Shaochong Zhou
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Steam Generator ◽  
Support System ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Reactor Coolant ◽  
Asme Code ◽  
Bolt Connection ◽  
Coolant System

The main equipments of the reactor coolant system include the steam generator, the reactor coolant pump, the pressurizer and the reactor coolant loop. The reactor coolant system is equipped with a steam generator for each of the two loops, and pressurizer is connected with the hot leg of loop 1 using the surge line. The main loop support system design of AP series greatly simplifies the RCS loop support system. Pressurizer supports consist of columns, lower lateral supports, upper lateral support and ring girder, and the steam generator supports consist of columns, lower lateral supports, upper lateral supports and intermediate lateral supports. Ring Girder of pressurizer consists of two semi-circular girders, vertical supports and splice connection of girder and the two half-ring girders are connected with splice connection using 11 bolts. The steam generator upper lateral support is mainly composed of bracket, snubber, pin and ubar and the ubar and the steam generator is connected via 16 bolts in the initial design. These bolts are to ensure the support junction can withstand the force and torque of various conditions of the reactor coolant system, which are important components of the main equipment support. There are large numbers of bolts in the splice connection of ring girder and ubar of upper lateral support of steam generator, and the bolts load was calculated using the uniform method in the general engineering design and analysis. During the design review it was found that the bolts load was uneven and in order to determine the non-uniformity of the bolts the finite element method was used to calculate the load on each bolt, and the resulting stress ratio was greater than 1 did not meet the requirements of the ASME Code. In this paper, the calculation method was studied and the design improvements for parts was made using the nonlinear analysis method to meet the requirements of ASME Code in the case of master supports of main equipment supports have been made good. At the same time the impact of bolts load because of gap was studied. It had very good economic benefits. The calculation and research of this paper show that the finite element method can calculate the force of bolts finely, and can get a more reasonable result than the empirical formula. It can be referred to when the multi-bolt connection structure needs to be refined, such as flange connection of important equipments and valves and flange and bolt design optimization.

scholarly journals Vibrations of a deformed half-space with inclusion under the influence of surface waves

2021 ◽  
Vol 274 ◽  
pp. 03027
Author(s):  
Bakhodir Rakhmonov ◽  
Ismoil Safarov ◽  
Mukhsin Teshaev ◽  
Ravshan Nafasov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Surface Waves ◽  
Strain State ◽  
Maximum Stress ◽  
Harmonic Waves ◽  
The Finite Element Method ◽  
Seismic Impacts ◽  
Good Agreement

There is a large number of underground tunnels of various shapes located in seismic zones that need to be protected from seismic impacts. The paper considers the effect of harmonic surface waves on a cylindrical inclusion of various shapes located in a viscoelastic half-plane. The main purpose of the study is to determine the stress-strain state of the obstacle when exposed to harmonic waves. The problem is solved by the finite element method. It was found that the maximum stress concentration is allowed at long waves, and the stress concentration with increasing depth and wavelength approaches the static value of stress. The reliability of the obtained research results is confirmed by good agreement with theoretical and experimental results obtained by other authors.

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