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 Concrete Filled Tubular Elements Joints Investigation

2018 ◽  
Vol 7 (3.2) ◽  
pp. 494
Author(s):  
Pavlo Semko ◽  
Serhii Skliarenko ◽  
Volodymyr Semko
Keyword(s):  
Numerical Modeling ◽  
Bearing Capacity ◽  
Strain State ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Tubular Structures ◽  
Stress Strain ◽  
Longitudinal Ribs ◽  
Stress Strain State ◽  
Methods Of Calculation

The stress-strain state and the bearing capacity of the dismountable joints of concrete filled tubular elements are investigated. The methods of calculation and constructive solutions of concrete filled tubular elements with joints are analyzed. Five new types of dismountable joints are proposed. Experimental studies of concrete filled tubular elements have been carried out. It was determined that the most effective for compression was a joint with a steel coupling and for bending the most effective was a joint with longitudinal ribs. The numerical modeling algorithm is presented; results are verified using experimental tests. A method for constructing N-M boundary dependences for concrete filled tubular structures is proposed. Bearing capacity diagrams for concrete filled tubular elements and their joints have been constructed. The costs of the materials needed to perform the joint as the example of a real construction for similar loads are analyzed. 

Experimental study of the strength and durability of metal-composite high-pressure tanks

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 49-56 ◽  
Author(s):  
A. M. Lepikhin ◽  
V. V. Moskvichev ◽  
A. E. Burov ◽  
E. V. Aniskovich ◽  
A. P. Cherniaev ◽  
...  
Keyword(s):  
High Pressure ◽  
Strain State ◽  
Full Scale ◽  
Fracture Mechanisms ◽  
Metal Composite ◽  
Test Results ◽  
Stress Strain ◽  
Pneumatic Pressure ◽  
Stress Strain State ◽  
Composite Tank

The results of unique experimental studies of the strength and service life of a metal-composite high-pressure tank are presented. The goal of the study is to analyze the fracture mechanisms and evaluate the strength characteristics of the structure. The methodology included tests of full-scale samples of the tank for durability under short-term static, long-term static and cyclic loading with internal pneumatic pressure. Generalized test results and data of visual measurements, instrumental and acoustic-emission control of deformation processes, accumulation of damages and destruction of full-scale tank samples are presented. Analysis of the strength and stiffness of the structure exposed to internal pneumatic pressure is presented. The types of limiting states of the tanks have been established experimentally. Change in the stress-strain state of the tank under cyclic and prolonged static loading is considered. Specific features of the mechanisms of destruction of a metal-composite tank are determined taking into account the role of strain of the metal liner. The calculated and experimental estimates of the energy potential of destruction and the size of the area affected upon destruction of the tank are presented. Analysis of test results showed that the tank has high strength and resource characteristics that meet the requirements of the design documentation. The results of the experiments are in good agreement with the results of numerical calculations and analysis of the stress-strain state and mechanisms of destruction of the metal-composite tank.

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.

Crack Resistance of the Self-Stressed Members Reinforced with FRP Bars

2018 ◽  
Vol 272 ◽  
pp. 244-249 ◽  
Author(s):  
Volha Semianiuk ◽  
Viktar V. Tur
Keyword(s):  
Initial Stress ◽  
Static Loading ◽  
Strain State ◽  
Crack Opening ◽  
The Self ◽  
Stress Strain ◽  
Diagram Method ◽  
Stress Strain State ◽  
Expansion Stage ◽  
Frp Bars

Fiber reinforced polymer (FRP) bars are widely used in building structures, especially that are exposed to the aggressive environment influence and other special conditions. Nevertheless, due to the low FRP (e.g. glass, basalt, aramid fibers reinforced polymers) bars modulus of elasticity, exceeding crack opening width, as well as deflections can be observed. FRP bars pretensioning is considered as an effective method of its structural performance increasing. Physico-chemical method of the FRP bars pretensioning based on the self-stressing concrete utilizing is an alternative to the mechanical method and in its turn doesn’t need for special devices and anchorage systems as well as qualified personnel. Assessment of the initial stress-strain state obtained during self-stressing concrete expansion stage in the reinforced self-stressed members is presented. Diagram method of the self-stressing parameters verification based on the static loading tests results is presented. Comparison of the initial stress-strain state obtained during concrete expansion stage and predicted by the proposed model, as well as assessment of its influence on the behavior at the static loading stage in cases of the self-stressed reinforced with FRP bars members and traditionally reinforced with steel bars self-stressed members was performed.

Numerical Modeling of Gasdynamic Processes and Processes of Deformation in Compressor of Model Test Bench of the Gas-Distributing Unit

2015 ◽  
Vol 799-800 ◽  
pp. 865-869 ◽  
Author(s):  
Vladimir Yakovlevich Modorskiy ◽  
Arthur Fadanisovich Shmakov
Keyword(s):  
Numerical Modeling ◽  
Model Test ◽  
Strain State ◽  
Test Bench ◽  
State Structure ◽  
Stress Strain ◽  
Stress Strain State ◽  
Physical Experiments ◽  
Heat Loads ◽  
Good Agreement

In this work results of numerical modeling of the gasdynamic processes and processes of deformation proceeding in the compressor of the model test bench of the gas-distributing unit are provided. Fields of pressure and temperatures, and also component of the stress-strain state structure taking into account the imported gasdynamic and heat loads are received. A good agreement with data of physical experiments is received.

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