scholarly journals Settlement and bearing capacity of water-saturated soils of foundations of finite width under static impact

Vestnik MGSU ◽  
2021 ◽  
pp. 463-472
Author(s):  
Zaven G. Ter-Martirosyan ◽  
Armen Z. Ter-Martirosyan ◽  
Ahmad Othman
Keyword(s):  
Bearing Capacity ◽  
Strain State ◽  
Water Saturation ◽  
Strength Properties ◽  
Finite Width ◽  
Stress Strain ◽  
Linear Deformation ◽  
Stress Strain State ◽  
Linear And Nonlinear ◽  
Water Saturated

Introduction. In case of brief exposure to static loads or dynamic loads, in conditions of absence of drainage, distribution of total stresses between the skeleton of soil and pore gas-containing water should be taken in account. The situation of the stress-strain state of the base is further complicated when we consider the degree of water-saturation of soil of the foundation (0.8 < Sr ≤ 1). The aim of the study is to pose and solve problem of the stress-strain state of a water-saturated soil massif, Including settlement and bearing capacity of a water-saturated base of a foundation of finite width, depending on the degree of water saturation of soils, taking into account the linear and nonlinear properties of the skeleton of soil and the compressibility of pore gas-containing water. Materials and methods. Henckyʼs system of physical equations are used as a calculation model to describe the relationship between deformation and stresses of soil, which takes into account the influence of the average stress on the deformation and strength properties of the soil. This system allows us to represent the linear deformation of the soil as the sum of the volumetric and shear components of the soil of this deformation. In addition allows us too to determine the deformation of the layer of soil, as part of the compressible thickness of the base of foundation with finite width under conditions of free deformations. Results. Depending on the linear and nonlinear deformation parameters, the settlement can be developed with a damped curve (S – p) and stabilize, and can be developed with a non-damped curve (S – p) and moved to the stage of progressive settlement. Conclusions. Solutions have been made for cases when the water-saturation of the base soils changes in the range of 0.8 to 1.0. It is shown that the settlement and bearing capacity of a water-saturated base significantly depends on the degree of water saturation of soils.

scholarly journals Experimental study of thermomechanical effects in water-saturated limestones during their deformation

2021 ◽  
Vol 247 ◽  
pp. 1-10
Author(s):  
Dmitry Blokhin ◽  
Pavel Ivanov ◽  
Oleg Dudchenko
Keyword(s):  
Thermal Radiation ◽  
Strain State ◽  
Water Saturation ◽  
Stability Control ◽  
Stress Strain ◽  
Stress Strain State ◽  
Water Saturated ◽  
Solid Bodies ◽  
Non Destructive ◽  
Stone Structures

Stability control of elements of stone constructions of various structures is a prerequisite for their safe operation. The use of modern methods of non-destructive diagnostics of the stress-strain state of such constructions is an effective, and in many cases the only way to control it. Studies of thermal radiation accompanying the processes of solid bodies deformation allowed to justify and develop a method that allows to obtain non-contact information about changes in the stress-strain state in various types of geomaterials, including limestones. However, studies of the water saturation influence of rocks on the thermal radiation parameters recorded in this way are currently superficial. Taking into account the water saturation degree of rocks is necessary when monitoring the mechanical condition of stone structures that are in direct contact with water. The main purpose of this work is to study the dependences of changes in the intensity of thermal radiation from the surface of limestone samples with different humidity under conditions of uniaxial compression. The obtained results showed the expected significant decrease in the mechanical properties (uniaxial compressive strength and elastic modulus) of water-saturated samples in comparison with dry ones. At the same time, a significant increase in the intensity of thermal radiation of limestone samples subjected to compression with an increase in their water saturation was recorded, which makes it necessary to take into account the revealed regularity when identifying changes in the stress state of stone structures established according to non-contact IR diagnostics in real conditions.

Analysis of the stress-strain state of copper M0B under different schemes of equal channel angular pressing and its effect on the structure and physical and mechanical properties

2019 ◽  
pp. 47-53
Author(s):  
L. F. Sennikova ◽  
G. K. Volkova ◽  
V. M. Tkachenko
Keyword(s):  
Equal Channel Angular Pressing ◽  
Strain State ◽  
Physical And Mechanical Properties ◽  
Strength Properties ◽  
Stress Strain ◽  
Loading Pattern ◽  
Stress Strain State ◽  
Angular Pressing ◽  
Fine Copper ◽  
Copper Structure

The results of studies of the stress-strain state of copper M0b after deformation under different schemes of equal channel angular pressing (ECAP) are presented. The level of macro and micro stresses in copper has been determined in various ECAP modes. It is shown that the strength properties, deformation porosity and parameters of the fine copper structure differ depending on the loading pattern.

scholarly journals Investigation of hydrogeomechanical parameters of loess massifs in conditions of technogenic underflooding and development of technical recommendations for strengthening of bases of foundations

2019 ◽  
Vol 28 (1) ◽  
pp. 173-179 ◽  
Author(s):  
I. O. Sadovenko ◽  
A. M. Puhach ◽  
N. I. Dereviahina
Keyword(s):  
Strain State ◽  
Quantitative Estimation ◽  
Residential Buildings ◽  
Finite Element Approximation ◽  
Element Approximation ◽  
Soil Base ◽  
Stress Strain ◽  
Elastic Mode ◽  
Stress Strain State ◽  
Water Saturated

Based on the analysis of actual data and the results of numerical modeling, dependencies of deformations of the investigated residential complex due to technogenic moistening of a loess massif of soils are investigated. It was established that a dynamics of subsidence of bench marks in time is closely correlated with a moistening mode. In order to form a picture of dynamics of development of moistening phases of the massif and a quantitative estimation of main factors of their formation, a numerical model of the loess massif was built, based on the finite element approximation of the section of built-up area of the residential complex. Stability of a soil massif was estimated by the character of development of plastic deformation zones. Analysis of a stress-strain state of a rock massif indicated that water-saturated soils are partially in a state of plastic flow in a base. The development of shear deformations is most characteristic within a zone of the main moistening, as well as a boundary of its front. Development of rupture disturbances at the edge of the contour of buildings corresponds with the formation of tear cracks. An intensification of subsidence of buildings with simultaneous frontal and subvertical technogenic moistening of loess soils can be noted. Model estimations of a stress-strain state of the pile foundation, considering the uneven subsidence that occurred along the perimeter of residential buildings, show that the elastic mode of their deformation has not been exhausted. Options of redistribution of loads from residential sections onto an additional pile field, regulated base moistening and grouting of soils are considered as engineering measures to prevent further deformation of the residential complex. Stabilization of a soil base by means of high-pressure cementation is the most acceptable in the present conditions. Technological scheme of cementation of the soil base is recommended, as well as measures after the base stabilization, such as monitoring of further deformations of the complex itself and parking structures, and possibilities of constructing auxiliary drainage.

Stress-Strain State of Saturated Beds of Foundations of Finite Width

2015 ◽  
Vol 51 (6) ◽  
pp. 273-281 ◽  
Author(s):  
Z. G. Ter-Martirosyan ◽  
A. Z. Ter-Martirosyan
Keyword(s):  
Strain State ◽  
Finite Width ◽  
Stress Strain ◽  
Stress Strain State

scholarly journals Mathematical modeling of stress-strain state of elements of joints of wooden structures on glued fiberglass washers

2021 ◽  
Vol 2131 (3) ◽  
pp. 032095
Author(s):  
M V Ariskin ◽  
D O Martyshkin ◽  
I V Vanin
Keyword(s):  
Mathematical Modeling ◽  
Bearing Capacity ◽  
Strain State ◽  
Single Component ◽  
Stress Strain ◽  
Design Models ◽  
Stress Strain State ◽  
Deformed State ◽  
Wooden Structures

Abstract Design models of single-component and three-component samples were developed on glued fiberglass washers in order to investigate the stress-strain state (SF) of the elements of joints of wooden structures. The picture and the nature of the actual stressed-deformed state of the wooden element with glued washers are obtained. Quite high bearing capacity of wooden structures connection is shown.

scholarly journals Predicting the Stress-Strain State of the Fractured Rock Massif on the Example of Interchamber Pillars

2019 ◽  
Vol 9 (2) ◽  
pp. 4228-4233
Keyword(s):  
Strain State ◽  
Numerical Models ◽  
Fractured Rock ◽  
Strength Properties ◽  
Rock Massif ◽  
Qualitative Description ◽  
Stress Strain ◽  
Stress Strain State ◽  
Geological Surveys ◽  
Spatial Geometry

The article describes the finding of the qualitative differences in the formation of the stress-strain state of a disturbed rock massif on the example of interchamber pillars with various methods of accounting for the structural disturbance and different spatial geometry of the cracks. Three numerical models are created with different methods of accounting for the disturbances in the massif continuity: in the first model, the strength of the massif is described by the Hoek and Brown criterion; the second and the third models are rock massifs for which violations in the continuity are formed explicitly, using ready-made templates of the systems of cracks presented in the Phase2 software product. The results obtained for the different models illustrate the inaccuracies occurring in assessing the disturbance of rock massif using score criteria. Models with underrated strength properties of the rock inaccurately describe the real mechanisms of the fractured massif: the qualitative description is not consistent with the results of field observations and geological surveys of rocks in general.

scholarly journals Numerical simulation of the stress strain state of base of the multi-helix screw pile under static loading in clay soil

2020 ◽  
pp. 28-36
Author(s):  
Volodymyr Sedin ◽  
Vladyslav Kovba ◽  
Yurii Volnianskyi ◽  
Kateryna Bikus
Keyword(s):  
Numerical Modeling ◽  
Bearing Capacity ◽  
Static Loading ◽  
Strain State ◽  
Clay Soil ◽  
Full Scale ◽  
Stress Strain ◽  
Foundation Construction ◽  
Stress Strain State ◽  
Screw Pile

A full-scale experiment was conducted to study the operation of a multi-helix screw pile under static pressing and pulling load in dusty clay soil. Based on the full-scale test of a multi-helix screw pile under static loading in dusty clay soil, numerical modeling of the stress-strain state of the base of the multi-helix screw pile was performed. Multi-helix screw piles are actively used all over the world, and have also become widespread in Ukraine. Foundations made of multi-helix screw piles are often used for industrial construction as well as the foundations of low-rise buildings and structures. Despite the growing demand for the use of multi-helix screw piles in modern construction, there is no official document calculating the features of their design and bearing capacity of a multi-helix screw pile. This poses a number of new tasks for engineers and geotechnical: a) development of new modern calculation methods; b) development and use of modern normative documents and recommendations for the calculation of foundations from multi-helix screw piles in various soil conditions; с) use of computer-aided design systems for calculation of complex geotechnical tasks; d) development of calculation models that will take into account nonlinear models of deformation of materials and soil base. Foundations made of multi-helix screw piles are a promising direction in the field of foundation construction due to the reduction of the duration of the foundation and its economic. This requires the development of regulations with recommendations for the calculation and use of multi-helix screw piles in the field of foundation construction, development of modern calculation models for the calculation of bearing capacity and settling of multi-helix screw piles in different geological conditions. Based on the results of the field study of the work of multi-helix screw piles in clay soils, numerical modeling of the stress-strain state of the base of the multi-turn pile was performed, and their results were compared.

scholarly journals Stress-strain state of the building foundations with taking into account the possible water saturation of loess soils

2020 ◽  
pp. 22-31
Author(s):  
Veronika Zhuk ◽  
Oleksandr Piatkov ◽  
Sergiy Tarambula
Keyword(s):  
Strain State ◽  
Water Saturation ◽  
Cost Effective ◽  
Loess Soil ◽  
Soil Base ◽  
Stress Strain ◽  
Engineering Structures ◽  
Load Bearing ◽  
Stress Strain State ◽  
Loess Soils

In Ukraine, the problem of construction on loess soils is relevant due to the widespread use of these soils and their negative property - the ability to give additional deformations of subsidence during water saturation. Flooding of territories by groundwater, emergency leaks from aquifers cause significant problems during the exploitation of buildings and engineering structures on such soils. Computer simulation of the interaction of the building with the soil base allows to investigate the influence of all negative factors on the change of the stress-strain state of both the soil base and the load-bearing structures of the building. The study of the interaction of the building with the foundation was performed using the software package LIRA-CAD. The interaction of the building with the soil base, the soils of which are able to reduce their mechanical properties with increasing humidity and give additional subsidence deformations, was studied. A variant design of the foundations was performed taking into account the occurrence of uneven deformations during subsidence of the loess soil due to its moistening in case of possible emergency losses from aquifers. The change of stress-strain state of the foundations of the building depending on the spatial rigidity of the foundation, the location of the soaking zone within the building spot, the shape and size of the zone of soil moisture is analyzed. It is shown that taking into account the possible water saturation of loess soils when calculating the collaborate of the building with the soil base, allows to obtain stress-strain state of foundations and load-bearing structures of the aboveground part of the building for the most unfavorable conditions that may occur. The search for the optimal variant of the foundation structures of the building, which, while remaining cost-effective, provides reliable operation of the building in conditions of possible occurrence of uneven deformations of subsidence of the soil base during water saturation of the layer of loess soils. According to the research results, a rational variant of the foundation structures has been designed taking into account the possible occurrence of non-uniform deformations.  

CALCULATION OF BENDING ELEMENTS OF WOOD AFTER THE ACTION OF LOW-CYCLE REPEATED LOADS ON THE CRITERION OF DEFORMATION DESTRUCTION

2020 ◽  
pp. 106-117
Author(s):  
E M Babich ◽  
S S Gomon
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Strain State ◽  
Repeated Loading ◽  
Building Structures ◽  
Deformation Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Layer Deformation

Existing norms of design for wooden constructions valid in different countries including Ukraine entirely disregard the effect of low-cycle repeated loadings during the operation of buildings and structures. The article deals with development of the bearing capacity computation of the bending elements manufactured from solid and glue-laminated wood exposed to repeated loadings in accordance with the deformation model.Equilibrium equations for computing the bending element made of wood after being exposed to repeated loadings are presented in the article. The deformation method is proposed for the computation of the rectangular wooden beams manufactured from solid and glued laminated wood with allowance for the occurrence of folds in the compression zone.The results of the research allow designing the solid and glue-laminated wooden constructions taking into consideration the possibilities of the material and peculiar features of the performance of the element, which in turn will allow choosing the cross-section of the elements of building structures more economically.On the basis of the study of the process of layer deformation by section height and the determination of the characteristics of the stress-strain state of these layers under the effect of repeated loading, it is possible to fulfill more accurate computation of the elements manufactured from wood at different stages of the stress-strain state through destruction.

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