RATIONALE FOR CHOOSING THE CHANGE MODEL OF THE DIELECTRIC PROPERTIES OF DISCONTINUOUS SYSTEMS

Purpose. The article deals with the insulation resistance of the track circuit as one of the parameters that affect the operating performance of the railway transport. To reduce the influence of the insulation resistance on the operation modes of the track circuits and the performance indicators of railway transport it is assumed to study the influence of crushed stone treatment on the value of dielectric permeability of the ballast bed. Methodology. The influence of material type for the surface treatment of crushed stone on the value of the dielectric permeability was assessed on the basis of the physical nature determination of the relative dielectric permeability. Determination of the relative dielectric permeability of granular media can only be indirect, as a consequence of incomplete adjoining of crushed stone grains and uncertainty of the pore volume. Thus, the calculations were performed by comparing the measured capacity for a medium with the known with measured medium capacity, for which it is necessary to define. That is, the more the measured capacity is changed, the more changes the dielectric permeability of the medium. Findings. Sleepers and ballast significantly change their electrical conductivity depending on the presence of moisture, ambient temperature changes, the presence of pollutants and other factors. The article analyzes the existing models to describe the dielectric properties of such systems. It has been established that coating the crushed stone ballast with organic substances influences the value of its relative dielectric permeability. The greatest effect of reducing this value is observed for the coatings based on rosin mixture and silicone. Originality. Authors proposed original method of dielectric properties increase of the permanent way by grains’ coating with nonwettable substances, on the surface of which is not formed a water film. Practical value. The article shows the possibility of minimizing the negative influence of reducing the isolation with maximum its elimination. It is proposed the solution of actual problem by eliminating the influence of insulation resistance on the modes of track circuits operation, which will eliminate the part of causes of the failure of signaling devices and reduce the number of cases of «false business»

ДОСЛІДЖЕННЯ ДЕФОРМАЦІЙНИХ ХАРАКТЕРИСТИК ҐРУНТОВОГО МАТЕРІАЛУ З ВИКОРИСТАННЯМ ВІДХОДІВ

Purpose. More often the qualified building materials are replaced by the industrial wastes for environmental improvement. This refers to both metallurgical slags and biological solids of water treatment plants. In order to understand the possibilities of their usage it needs studying deformation properties of composite soil materials with industrial wastes addition. Methodology. The soil of real buildings and structures foundation is in the complicated conditions and the stress-strained state. While studying this state the total deformation modulus Е0 is used as the deformation characteristic. This one is determined according to the results of sample soil testing in the compression instrument (odometer). This instrument prevents the possibility of lateral expansion of sample soil under the vertical load. Findings. As a result of the testing the compression curves are plotted as the dependence of the porosity coefficient on pressure. These data allow determining the compressibility coefficient and the strain modulus. It is found that a biological solids addition increases the compressibility coefficient four times compared to the clay. The two types of samples are compared. The first type contains 50% of biological solids. The second type contains 50% of biological solids and 50% of slag. The comparison shows that the second type is compressed twelve times less. An addition into the clay of biological solids increases the strain modulus from 7.8 to 20.3 MPa. The slag increases the strain modulus to 52.7 MPa. Originality. While making the composition based clay materials the functional groups of biological solids interact with hydroxyl groups which are placed on the surface of clay particles and form a spatial structure. Besides an addition of biological solids contributes to peptization, soil aggregates destroy themselves, and form contacts between separate particles. It causes the decrease of soil compressibility due to the total porosity decrease. An addition of slag results in formation of optimal structure where particles of less sizes are placed in layers between bigger particles. Practical value. An application of biological solids and slag provides the increased load-carrying capacity of soil, extending of raw material sources while improving the environmental situation in the cities. Also it provides the recycling of reinforced soil.Цель. Для повышения экологической чистоты все чаще кондиционные строительные материалы заменяют отходами производств. Это касается как металлургических шлаков, так и активного ила станций биологической очистки городских сточных вод. Для выяснения возможности их использования необходимо исследовать деформационные свойства композиционных грунтовых материалов с добавлением указанных отходов. Методика. При изучении напряженно-деформированного состояния грунта в сложных условиях, в которых и находится грунт оснований реальных зданий и сооружений, в качестве деформационной характеристики используют модуль общей деформации Е0. Эту характеристику определяли по результатам испытаний образцов грунта в компрессионных приборах (одометрах), которые исключают возможность бокового расширения образца грунта при его нагружении вертикальной нагрузкой. Результаты. В результате измерений были построены компрессионные кривые зависимости коэффициента пористости от давления. По этим данным определен коэффициент сжимаемости и модуль деформации. Установлено, что добавление активного ила уменьшает коэффициент сжимаемости образцов в 4 раза по сравнению с глиной. По сравнению с образцами, которые содержат 50 % активного ила, образцы с добавлением 50 % шлака уменьшают сжимаемость в 12 раз. Добавление в глину активного ила позволяет увеличить модуль деформации с 7,8 до 20,3 МПа, шлак повышает эту величину до 52,7 МПа. Научная новизна. При изготовлении композиционного материала на основе глинистых грунтов функциональные группы активного ила взаимодействуют с гидроксильными группами, расположенными на поверхности глинистых частиц, с образованием пространственной структуры. Кроме того, введение активного ила способствует пептизации и разрушению грунтовых агрегатов, образованию контактов между отдельными частицами, что приводит к уменьшению сжимаемости образцов за счет уменьшения общей пористости. Добавление шлака способствует образованию оптимальной структуры образцов с размещением меньших по размерам частиц в слоях между большими частицами. Практическая значимость. Применение активного ила и шлака обеспечивает повышенную несущую способность грунта, расширение сырьевой базы для его получения с одновременным улучшением экологической ситуации в городах, обеспечивает возможности вторичного использования укрепленного грунта.Мета. Для підвищення екологічної чистоти все частіше кондиційні будівельні матеріали замінюють відходами виробництв. Це стосується як металургійних шлаків, так і активного мулу станцій біологічного очищення міських стічних вод. Для з’ясування можливості їх використання необхідно дослідити деформаційні властивості композиційних грунтових матеріалів із додаванням вказаних відходів. Методика. При вивченні напружено-деформованого стану ґрунту в складних умовах, в яких і знаходиться ґрунт основ реальних будівель та споруд, як деформаційну характеристику застосовують модуль загальної деформації Е0. Цю характеристику визначали за результатами випробувань зразків ґрунту в компресійних приладах (одометрах), які виключають можливість бічного розширення зразка ґрунту при його навантажуванні вертикальним навантаженням. Результати. У результаті вимірювань було побудовано компресійні криві залежності коефіцієнта пористості від тиску. За цими даними визначено коефіцієнт стисливості та модуль деформації. Встановлено, що додавання активного мулу зменшує коефіцієнт стисливості зразків у 4 рази порівняно з глиною. У порівнянні зі зразками, які містять 50 % активного мулу, зразки з додаванням 50 % шлаку, зменшують стисливість у 12 разів. Додавання в глину активного мулу дозволяє збільшити модуль деформації з 7,8 до 20,3 МПа, шлак підвищує цю величину до 52,7 МПа. Наукова новизна. При виготовленні композиційного матеріалу на основі глинистих ґрунтів функціональні групи активного мулу взаємодіють із гідроксильними групами, розташованими на поверхні глинистих частинок, із утворенням просторової структури. Крім того, введення активного мулу сприяє пептизації - руйнуванню агрегатів ґрунту і утворенню контактів між окремими частинками, що й призводить до зменшення стисливості зразків за рахунок зменшення загальної пористості. Додавання шлаку сприяє утворенню оптимальної структури зразків із розміщенням менших за розмірами частинок у прошарках між більшими частинками. Практична значимість. Застосування активного мулу та шлаку забезпечує підвищену несучу здатність ґрунту, розширення сировинної бази для його отримання з одночасним покращенням екологічної ситуації у містах, забезпечення можливості вторинного використання укріпленого ґрунту

THE STUDY OF DEFORMATION CHARACTERISTICS OF SOIL MATERIALS WITH THE USAGE OF WASTES

Purpose. More often the qualified building materials are replaced by the industrial wastes for environmental improvement. This refers to both metallurgical slags and biological solids of water treatment plants. In order to understand the possibilities of their usage it needs studying deformation properties of composite soil materials with industrial wastes addition. Methodology. The soil of real buildings and structures foundation is in the complicated conditions and the stress-strained state. While studying this state the total deformation modulus Е0 is used as the deformation characteristic. This one is determined according to the results of sample soil testing in the compression instrument (odometer). This instrument prevents the possibility of lateral expansion of sample soil under the vertical load. Findings. As a result of the testing the compression curves are plotted as the dependence of the porosity coefficient on pressure. These data allow determining the compressibility coefficient and the strain modulus. It is found that a biological solids addition increases the compressibility coefficient four times compared to the clay. The two types of samples are compared. The first type contains 50% of biological solids. The second type contains 50% of biological solids and 50% of slag. The comparison shows that the second type is compressed twelve times less. An addition into the clay of biological solids increases the strain modulus from 7.8 to 20.3 MPa. The slag increases the strain modulus to 52.7 MPa. Originality. While making the composition based clay materials the functional groups of biological solids interact with hydroxyl groups which are placed on the surface of clay particles and form a spatial structure. Besides an addition of biological solids contributes to peptization, soil aggregates destroy themselves, and form contacts between separate particles. It causes the decrease of soil compressibility due to the total porosity decrease. An addition of slag results in formation of optimal structure where particles of less sizes are placed in layers between bigger particles. Practical value. An application of biological solids and slag provides the increased load-carrying capacity of soil, extending of raw material sources while improving the environmental situation in the cities. Also it provides the recycling of reinforced soil

Non-destructive control method of the state of objects operating long time

The development of a diagnostic system is a complex engineering problem aimed at preventing damage caused by deteriorating properties of the materials and structures. This article presents the method of nondestructive testing of change control of concrete structures. The analysis of literature data shows that the overwhelming majority of studies are devoted to the change in electrical resistance of concrete in the collection of its strength, and practically no analogous studies regarding its aging are presented. Theoretical substantiation of the change in electrical concrete characteristics (conductivity, resistance) is given with a change in its strength. A work over-bridge in operation more than 30 years has been surveyed. The experimental part consisted in measuring the electrical potentials on the bridge structures, as well as in determining the strength of the material at the same points. Correlation dependence between the measured electric potential value and the strength of the samples taken from the bridge structures were obtained

Non-destructive control method of the state of objects operating long time

The development of a diagnostic system is a complex engineering problem aimed at preventing damage caused by deteriorating properties of the materials and structures. This article presents the method of nondestructive testing of change control of concrete structures. The analysis of literature data shows that the overwhelming majority of studies are devoted to the change in electrical resistance of concrete in the collection of its strength, and practically no analogous studies regarding its aging are presented. Theoretical substantiation of the change in electrical concrete characteristics (conductivity, resistance) is given with a change in its strength. A work over-bridge in operation more than 30 years has been surveyed. The experimental part consisted in measuring the electrical potentials on the bridge structures, as well as in determining the strength of the material at the same points. Correlation dependence between the measured electric potential value and the strength of the samples taken from the bridge structures were obtained

Independent diagnostic computer systems with the ability to restore operational characteristics of construction facilities

Progress in modern engineering devices favours the development of independent computer systems of intelligent change management of operational characteristics of construction facilities. The article deals with the continuous control system (monitoring) of the soil moisture. The capillary sensor applied provides a far higher accuracy in determining the moisture than it is achieved by discrete determination of soil electrical characteristics which depend on the concentration and proportion of salts dissolved in the soil as well as the particle-size distribution. A flowchart of the diagnostic system was developed; it does not only transfer the data from the sensors, processes them and informs the operator, but also gives the possibility of autonomous inclusion of mechanisms to eliminate the emerged damages. Thus, while monitoring the soil moisture of hillsides, embankments and cuts slopes it prevents their shifts and other damages

Independent diagnostic computer systems with the ability to restore operational characteristics of construction facilities

Progress in modern engineering devices favours the development of independent computer systems of intelligent change management of operational characteristics of construction facilities. The article deals with the continuous control system (monitoring) of the soil moisture. The capillary sensor applied provides a far higher accuracy in determining the moisture than it is achieved by discrete determination of soil electrical characteristics which depend on the concentration and proportion of salts dissolved in the soil as well as the particle-size distribution. A flowchart of the diagnostic system was developed; it does not only transfer the data from the sensors, processes them and informs the operator, but also gives the possibility of autonomous inclusion of mechanisms to eliminate the emerged damages. Thus, while monitoring the soil moisture of hillsides, embankments and cuts slopes it prevents their shifts and other damages