20 research outputs found
Assessment of Middle Pleistocene terrain forming fine-grained till soil properties.
No full textThe till fine soil composition, structure, and properties exhibit significant variability, making it a subject of extensive research. This study aims to analyze the composition, physical, and mechanical properties of the Middle Pleistocene terrain forming till fine soil and identify the primary factors influencing its properties. The research findings will help correlate the indicators that cause changes in the soil's properties, leading to a better understanding of its overall behavior. The research determined that soil with the studied granulometric composition could be categorized according to the most prominent classifications of P. K. Robertson (2009, 2016) into various soil behavior types. These classifications aid in assessing soil behavior under mechanical impact, regardless of its determined name. Additionally, empirical equations were employed to describe and establish relationships between the physical and mechanical properties of the soil. The mechanical properties could be evaluated based on the ratio of natural moisture content, clay fraction content, and cone resistance. The natural moisture content exerting the most significant influence on the oedometric modulus of deformations. Moreover, the angle of internal friction is primarily influenced by clay fraction content and cone resistance. For the first time, the overconsolidation ratio of the Middle Pleistocene terrain forming till fine soil was evaluated and based on laboratory studies. The investigated soil can be classified as lightly overconsolidated (OCR < 4), allowing the application of corresponding mechanical principles
TRAFFIC POLLUTION ASSESSMENT USING ARTIFICIAL NEURAL NETWORK AND MULTIVARIATE ANALYSIS
No full textThe work addressed a study on pollution caused by traffic on the highway. In particular, it was considered the concentration of pollutant, resulting from the passage of vehicles on the freeway. Five different stations (sensors and samples) used to collect data. The data collection period around six months. Also, the following parameters were detected: wind speed and direction, temperature and traffic flow rate. Data processed with Multivariate Analysis and Artificial Neural Network approach. The best model it obtained with Artificial Neural Network approach. In fact, this model presented the best fit to the experimental data
Geotechnical characterization of a triassic clay-cement mixes.
No full textGeotechnical Characterization of a Triassic Clay-Cement Mix. This thesis deals with modification of Triassic clay with cement, using soil-cement mixing method. For tracking of the changes in geotechnical parameters between clay-cement mix and natural Triassic clay, data from earlier researches were used. During the preparation of the clay-cement mix, 40 % of water was added to the dry natural clay. Also there were made three different groups of specimens were they had different amount of cement (5, 10 and 15 %). The tests were executed during three stages of stiffening – a 2, 14 and 26 days after the start of the research. During the Research a strict schedule was made. The time of execution of the test were shown in the schedule. Geotechnical properties of clay-cement mix were established. The density, water content, index of plasticity, consistency, and liquid limits were obtained. Unconfined undrained compression tests were conducted and parameters of unconfined shear strength were obtained. Analyzed data has shown that the clay-cement mixtures with 15 % of cement in the content has improved the most, the cement addition of 5 and 10 % has a low impact to the properties of strength. The relevance of the thesis is to suggest the usage of Triassic clay-cement mix as the part of an engineered barrier through the construction of a new Near Surface Repository facility will be designed, and subsequently constructed, for the disposal of Short-lived Low and Intermediate Radioactive Waste
Flat dilatometer tests in the till soils of stabatiskes site.
No full textFlat Dilatometer Tests in the Till Soils of Stabatiskes Site The biggest part of territory of Lithuania is covered of till. For the most detailed researches of soil there it is necessary to pick–up mostly modern and exact geotechnical research methods. The outside research methods are used to get the geotechnical characteristics. One of the most popular research methods in the world is dilatometer test. This one is not the most useful in Lithuania, so that was the reason and decision to analyze the usage of dilatometers test for till soils in Lithuania. The work object – till soils in the territory of Lithuania. Testing soils place – Ignalina nuclear power plant radioactive waste within the territory of Stabatiškės site. The aim of paper – the date processing of material index (ID), overconsolidation ratio (OCR) and dilatometer modulus (ED), reliability evaluations, the correlations with other test methods (CPT, DPSH). The work tasks are - • to check and introduce the method of dilatometer test (DMT); • to make an accountings of research data; • to identify the correlation relation in till soils in Lithuania between dilatometer test and cone penetration test; • to estimate the geotechnical characteristics then using correlation dependencies. After analyzing the operating principles and the usage opportunities of dilatometer test, counted clay soil geotechnical characteristics using MS Microsoft excel, dilatometers test was compared with cone penetration test, laboratories and also dynamic penetration test. The last one does not has any relation with dilatometer test, so the counting’s not given. The results shows, that DMT method can be fully used for soil tests in Lithuania’s territory to get geotechnical characteristics not only of till soils, but also of sand soils
Evaluation of Moraine Loams' Filtration Properties
No full textIn Lithuania, surface moraine loam, clay and other lithologic varieties with low permeability take around 60% of the territory. Roads, railway tracks, bridges, dumps intended for keeping waste of different level of danger and other overground structures are built in these areas. Moraine formations with low water permeability become the foundation for earth bank, roads, bridge supports, dumps and other engineering structures. Through these foundations water filtration, infiltration, movement of capillary water and evaporation to the atmosphere continue during the entire period of operation. In wintertime, the volumetric changes of water, contained and freezing in these soils, and water migration in soil towards the surface of freezing determine deformations of foundations or road surface and the occurrence of frost cracks. All the mentioned water migration processes in the layers take place in various directions and in different intensity. This determines the change in geomechanical and geofiltration properties of foundation soils. Foundation soil deformations are likely also due to the processes of drying, bloating and filtration of clayey soils. Thus, the goal of the present work is to evaluate the evolution of filtration features and evaporation intensity of moraine loam in time. The continuous duration of laboratory investigations was over 10 months. For filtration, the filtrometer was used containing the Proctor Standard moulds, water deaeration device and pressure measuring stand with three tubes of different diameter (piezometers). Water and air temperature and relative humidity of the laboratory were measured during each experiment
Klaipėdos uosto smulkiųjų gruntų savybių ypatumai
No full textIn the article, taking Klaipėda quays 7, 8 and 9 as examples, peculiarities of fine soil (silty clay, silty sandy clay and clayey silt) grain size distribution, physical state and mechanical properties are discussed. It was established that in these soils of a very similar physical state, the grain composition determines their mechanical properties.Lietuviška santrauka. Klaipėdos uosto krantinių rekonstrukcijos vietose yra sudėtingas geologinis pjūvis. Nors didesniąją pjūvio dalį sudaro glacigeninės kilmės smulkieji rišlūs gruntai, tačiau juose randama dulkingo molio tarpsluoksnių ir intarpų. Statybos metu jie gali išmirkti ir būti išplauti. Atlikti tyrimai rodo, kad smulkiųjų gruntų rūšys – tai moreninis dulkingas molis, moreninis dulkingas smėlingas molis ir nemoreniniai molingi dulkiai. Visi minėti gruntai pasižymi panašia fizine būkle, tačiau skirtinga granuliometrinė sudėtis lemia įvairias stiprumo rodiklių vertes ir jų pokyčius esant skirtingomis ašinėmis deformacijomis
Broniaus Radzevičiaus "Priešaušrio vieškeliai" (1979-1985) kaip egzistencialistinis romanas
No full textBroniaus Radzevičiaus „Priešaušrio vieškeliai" (t. 1 - 1979; t. 2, po autoriaus mirties parengtas Juozo Apučio, - 1985) - vienas labiausiai aptartų ir iki šiol tebeanalizuojamų lietuvių romanų. Jį nagrinėjo Petras Bražėnas, Liudvikas Gadeikis, Arvydas Šliogeris, Jūratė Sprindytė, Valdas Papievis, Saulius Žukas, Algis Kalėda, Danas Lapkus, Audinga Satkūnaitė. Šiam kūriniui skirta Dainiaus Vaitiekūno monografija „Pasakojimas B . Radzevičiaus. Priešaušrio vieškeliuose' " (2004). Kur slypi Radzevičiaus romano traukos paslaptis? Kokios idėjos bei kokie meniniai sprendimai traukia filosofų ir literatūrologų dėmesį? Reikšminiai žodžiai: Autorius; Bronius Radzevičius; Egzistencialistinis romanas; Egzistencialistinis romanas, absurdo filosofija, naratorius; Pasakotojas; Personažas; Author; Bronius Radzevičius; Character; Existencial novel; Existentialist novel; Narrator; Phylosophy of the absurdThe novel Priešaušrio Vieškeliai (Predawn Highways) by Bronius Radzevičius is one of the most discussed and still being analysed Lithuanian novels. Where is the secret of the popularity of this novel? What ideas and creative solutions are in the focus of attention for philosophers and literary researchers? The article aims at seeking to explain why Priešaušrio Vieškeliai could be regarded as an existential novel. The conclusion has been drawn that this novel could be distinguished from analogical Lithuanian novels by contemplation of Camus's philosophy, metaliterary conception, autobiographical features, reflections of absurd philosophy, etc
The Cathedral of Vilnius: Problems and Features of Natural Conditions
No full textThe Cathedral of Vilnius is one of the main architectural monuments in Lithuania. This structure was built in unfavorable geological conditions. Due to this reason, the foundation of the building subsides; there occur wall deformations and cracks. Preservation of the building is today’s urgent problem. When evaluating the geologic environment from the perspective of engineering, construction works require deep analysis of the following key environment components and discuss them: relief, soils of geologic structure and their geotechnical properties, conditions of underground water occurrence and geological processes, and condition of the foundation. The article provides the brief history of construction and reconstruction of the Cathedral based on archival studies, the description of engineering geological conditions, and the archeologic and historic material of the evaluation of the foundation
Investigation of Geofiltration Properties of Clay Soils
No full textFiltration properties of clay (Kuksa mine, Lithuania) were investigated and analysis of the results was done. Investigations were carried out using a permeameter with a varying hydraulic head. A potential dependence of the clay hydraulic conductivity values on the filtration process duration as well as hydraulic gradient and compaction range were determined. The importance of the clay structural peculiarities, carrying out filtrations through clay paste, natural structure and compacted samples was evaluated. It was determined that the clay hydraulic conductivity values varied greatly only at the beginning of the filtration while, later on, when continuing the filtration for a few days, the change reduced. This shows that, during the filtration, there are structural clay-forming unit rearrangements that are taking place. The filtration investigation of the clay paste studies show that there exist clay structural links different changes the filtration capacity of clay. The determined varying behaviour of the clay and the clay paste in the course of filtration as well as under various loads must be evaluated in the design and reconstruction of roads with subgrade of the clayey soils
Impact of covid-19 on international business: labor market and recruitment transformation.
No full textThe main purpose of this master thesis is to identify the labor market opportunities and challenges faced by international business in the recruitment process at COVID - 19 circumstances. The work consists of three main parts: literature analysis, research and analysis of the results, conclusions and recommendations. The first part summarizes the prevailing opinion prior to COVID - 19 on the importance of human resources for the competitiveness of international business and the recruitment and selection methods used by the business. The second one analyzes the changes in the situation in the labor market and employment processes after COVID - 19 in comparison with the situation before. The main objectives of the study are to identify the impact of COVID-19 to business and labor market; to analyze the impact of the COVID-19 to demand and supply of human resources; examine the key challenges businesses is facing in recruitment and selection process during a pandemic period. The study revealed that the impact of COVID-19 on human resources is related to the adaptation of workforce, coping with changes in organizations, challenges related to the recruitment and integration of new employees. The business has faced challenges due to COVID-19, as selection methods are not adapted to distance communication, the psychological and emotional environment has changed, there is a lack of experience in adapting recruitment processes and assessing opportunities to exploit market conditions. Thus, a business operating in an international environment needs to assess the competitiveness of the labor market not only to attract new employees to the organization, but also to retain existing talent. The author believes that the results of the study may be useful for companies intending to adapt to new labor market trends after the second wave of the COVID-19 pandemic
