scholarly journals A Study on Seismic Analysis Method in the Cross Section of Underground Structures by Means of Static Finite Element Method.

1995 ◽  
pp. 139-148
Author(s):  
Akira Tateishi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
Seismic Analysis ◽  
Analysis Method ◽  
Underground Structures ◽  
The Cross ◽  
Element Method

scholarly journals Assessment of Rectangular Cavity in Concrete Gravity Retaining Wall using Finite Element Method

2019 ◽  
Vol 8 (4) ◽  
pp. 2656-2661
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Distribution ◽  
Cross Section ◽  
Retaining Wall ◽  
Rectangular Cavity ◽  
Gravity Retaining Wall ◽  
The Cross ◽  
Conditions Of Stability ◽  
Element Method

The design of the Gravity retaining wall (GRW) is a trial and error process. Prevailing conditions of backfill are used to determine the profile of GRW, which proceeds with the selection of provisional dimensions. The optimum section is having factors of safety of stability higher than the allowable values and stresses in the cross-section smaller than permissible. The cross-section is designed to fulfill conditions of stability, subjected to very low stresses. The strength of the material, which is provided in the cross-section remains unutilized. A computer program is developed to find stresses at various locations on the cross-section of GRW using the Finite Element Method (FEM). A discontinuity in the form of a rectangular cavity is introduced in the cross-section of GRW to optimize it. The rectangular cavity is introduced in the cross-section of GRW at different locations. An attempt is made in this paper to find the stress distribution in the gravity retaining wall cross-section and to study the effect of the rectangular cavity on the stress distribution. Two cases representing different locations are considered to study the effect of the cavity. The location of the cavity is distinguished by the parameter w, the effects of cases with varied was 0.2305 (Case-I) and 0.1385 (Case-II) are observed. The cavity, which is provided not only makes the wall structurally efficient but also economically feasible.

Closed-Form Approximate Formulas for Torsional Analysis of Hollow Tubes with Straight and Circular Edges

2009 ◽  
Vol 25 (4) ◽  
pp. 401-409 ◽  
Author(s):  
A. Doostfatemeh ◽  
M. R. Hematiyan ◽  
S. Arghavan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Closed Form ◽  
Cross Section ◽  
Stress Function ◽  
Analytical Formulas ◽  
The Cross ◽  
Torsional Analysis ◽  
Approximate Formulas ◽  
Element Method

ABSTRACTSome analytical formulas are presented for torsional analysis of homogeneous hollow tubes. The cross section is supposed to consist of straight and circular segments. Thicknesses of segments of the cross section can be different. The problem is formulated in terms of Prandtl's stress function. The derived approximate formulas are so simple that computations can be carried out by a simple calculator. Several examples are presented to validate the formulation. The accuracy of formulas is verified by accurate finite element method solutions. It is seen that the error of the formulation is small and the formulas can be used for analysis of thin to moderately thick-walled hollow tubes.

Modeling of the impact of hold-down forces on the accuracy of the workpiece shape using the finite element method

2021 ◽  
pp. 9-20
Author(s):  
A.V. Zaitsev ◽  
A.N. Izosimov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
The Body ◽  
Machining Process ◽  
Mechanical Processing ◽  
The Finite Element Method ◽  
The Cross ◽  
The Impact ◽  
Element Method

In the article, the modeling of the impact of hold-down forces on the accuracy of the shape of the workpiece using the finite element method was carried out. The operation of mechanical processing (turning cut) of a workpiece of the body of rotation type on a milling machine with basing and fixing along the inner cylindrical surface of the workpiece is considered. The study was conducted for four different types of machine retaining devices used on machines of this group. A consistent description and illustration of the method of modeling the process of the impact of hold-down forces on the workpiece is made for each type of the device under consideration. The force constraints and effects imposed on the model are described and illustrated, the parameters of the finite element grid used in modeling are presented, the displacement profiles obtained in the modeling process and the stages of modeling the machining process are described, and the values of the largest deviations from the shape of the workpiece are determined. The results of the modeling are presented: a qualitative picture of the shape errors obtained as a result of mechanical processing — the values of the largest deviation from the roundness and the largest deviation from the cross-section profile of the workpiece to be processed, as well as the shape of the cutting obtained in the cross-section of the workpiece for each type of the devices under consideration. On the basis of the obtained results, estimates of the degree of accuracy of the shape and the relative geometric accuracy provided by the considered devices were made in accordance with GOST 24643–81. The conclusion is made about the suitability of using the considered variants of machine retaining devices for the proposed technological process according to the criterion of the provided accuracy of the shape of the processed surface. English version of the article is available at URL: https://panor.ru/articles/modeling-the-influence-of-the-fastening-forces-on-the-accuracy-of-the-workpiece-shape-using-the-finite-element-method/65043.html

About Contemporary Seismic Analysis of Underground Structures

2018 ◽  
Vol 931 ◽  
pp. 91-99
Author(s):  
Alexander M. Belostotskiy ◽  
Pavel A. Akimov ◽  
Dmitry S. Dmitriev
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Soil Structure ◽  
Seismic Analysis ◽  
Underground Structure ◽  
Soil Structure Interaction ◽  
Underground Structures ◽  
Structure Interaction ◽  
Second Stage ◽  
Element Method

This paper is devoted to actual problems of seismic analysis of underground structures. Brief classification and overview of corresponding methods of analysis (force-based methods, displacement-based methods, numerical methods of seismic analysis of coupled system “soil – underground structure” and approaches to problems of soil-structure interaction) is presented. Special static finite element method with substructure technique for seismic analysis of underground structures is described. Dynamic soil-structure interaction system can be decomposed into three sub-structures: structure, near-field and far-field soil. The first stage of static finite element method is solving the free field shear stress, acceleration, velocity and displacement, when the moment that the relative displacement of the soil that the underground structure located in reaches the maximum. The second stage is computing of internal forces and parameters of boundary conditions. The third stage is construction of the static finite element model and imposing the loads and constrains computed at the second stage and then making a static analysis.

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.

Random finite element method for the seismic analysis of gravity dams

2018 ◽  
Vol 171 ◽  
pp. 405-420 ◽  
Author(s):  
M.A. Hariri-Ardebili ◽  
S.M. Seyed-Kolbadi ◽  
V.E. Saouma ◽  
J. Salamon ◽  
B. Rajagopalan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Seismic Analysis ◽  
Gravity Dams ◽  
Random Finite Element Method ◽  
Random Finite Element ◽  
Element Method

Landslide Simulation Using Limit Equilibrium and Finite Element Method

2016 ◽  
Vol 857 ◽  
pp. 555-559 ◽  
Author(s):  
Zuhayr Md Ghazaly ◽  
Mustaqqim Abdul Rahim ◽  
Kok Alfred Chee Jee ◽  
Nur Fitriah Isa ◽  
Liyana Ahmad Sofri
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Main Concern ◽  
Analysis Method ◽  
Stability Of Slope ◽  
The Stability ◽  
Element Method

Slope stability analysis is one of the ancient tasks in the geotechnical engineering. There are two major methods; limit equilibrium method (LEM) and finite element method (FEM) that were used to analyze the factor of safety (FOS) to determine the stability of slope. The factor of safety will affect the remediation method to be underdesign or overdesign if the analysis method was not well chosen. This can lead to safety and costing problems which are the main concern. Furthermore, there were no statement that issued one of the analysis methods was more preferred than another. To achieve the objective of this research, the soil sample collected from landslide at Wang Kelian were tested to obtain the parameters of the soils. Then, those results were inserted into Plaxis and Slope/W software for modeling to obtain the factor of safety based on different cases such as geometry and homogenous of slope. The FOS obtained by FEM was generally lower compared to LEM but LEM can provide an obvious critical slip surface. This can be explained by their principles. Overall, the analysis method chosen must be based on the purpose of the analysis.

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