rss_2.0Ovidius University Annals of Constanta - Series Civil Engineering FeedSciendo RSS Feed for Ovidius University Annals of Constanta - Series Civil Engineering and Materials Used in the Construction of the Mosques in the Dobrogea Area<abstract> <title style='display:none'>Abstract</title> <p>In this paper the authors show the investigations importance on the constituent materials of the mosques, to understand their behaviour in the environment actions, but also for the using off efficient intervention measures. In this paper a comparative analysis is made between three mosques on the territory of Dobrogea, which were built in different periods, and located in areas with different location characteristics.</p> </abstract>ARTICLEtrue of Natural Frequencies to Traffic Pedestrians’ Comfort of Some Steel Footbridges<abstract> <title style='display:none'>Abstract</title> <p>In this paper several aspects regarding the dynamic behaviour of the steel footbridge structures under the action of the loads generated by the pedestrians’ displacement, correlated with the traffic comfort of the pedestrians crossing the structure are presented. The crossing pedestrians’ comfort criterion requires the values of vibration frequencies and accelerations of the structures in certain limits so that the vibration amplification or resonance is avoided. The paper takes under investigation eight footbridges on steel, composite steel-concrete girders and a cable stayed structure from the viewpoint of frequencies in vibration Mode 1 in a vertical plane, generated by their own weight - natural frequency, or from a partial pedestrian loading, as well as the resulting resonance risk and the traffic comfort.</p> </abstract>ARTICLEtrue the Current State of Research on Urban Regeneration in Waterfront Cities<abstract> <title style='display:none'>Abstract</title> <p>The purpose of this study is to combine two bodies of literature and theory: the first on urban change and coastal regeneration, and the second on the ideas of concerns that influence and shape urban regeneration practice. The goal of this paper is to conduct a review of the pertinent literature on this subject. It will analyze urban change theories as well as the key causes that have shaped transformation over the last few decades. Additionally, it aims to define urban regeneration functionally, to explain its principles and features, and to present a brief history of its growth in Romania. Finally, this work seeks to establish the research niche by examining the evolution of waterfront urban rehabilitation.</p> </abstract>ARTICLEtrue Analysis and Classification of Pollutants in the Nokoué Lake (Benin)<abstract> <title style='display:none'>Abstract</title> <p>The water quality of a lake is an important factor for human health. Since the pollution level of the Nokoué Lake (Benin) became a concern, the present study was carried out to better understand and manage the quality of the surface water of this lake, to reduce the risks to damage the population health and the ecosystem equilibrium. The objective of the present work is the statistical study of the pollutants concentration data using Principal Component Analysis (PCA) and clustering. The concentration of five pollutants, namely NO<sub>3</sub><sup>−</sup>, NH<sub>4</sub><sup>+</sup>, NT (total nitrogen), PO<sub>4</sub><sup>3−</sup>, and total phosphates (PT) were sampled on thirty-three sites of the Nokoué Lake and analyzed. Three principal components have been selected and the sites have been grouped in three clusters, one of them containing only the sites on Cotonou.</p> </abstract>ARTICLEtrue of Susceptibility to Flash Floods in the Vărbilău River Catchment<abstract> <title style='display:none'>Abstract</title> <p>Identification of areas susceptible to flash floods is essential to establish measures that will help the population in case of a hazard. Therefore, the purpose of the present article is to identify the areas that present a high susceptibility to flash-floods in the Vărbilău catchment. The area, located in the Prahova region, was chosen due to the complexity of the hydrological phenomena. To determine the susceptibility to flash floods, the Flash Flood Susceptibility Index (FFSI) was calculated by integrating ten factors that play an essential role in the flash floods formation. Areas located downstream and in the middle of Vărbilău basin present a low risk, while locations in the northwest (upstream of Luţu Roşu and Scurteşti) present a high risk to flash-floods due to steep slope, narrow valleys, solid rocks, and land use.</p> </abstract>ARTICLEtrue Methods and Techniques Used for Earthen Buildings<abstract> <title style='display:none'>Abstract</title> <p>In all arid regions of the globe, but also in those with temperate climates, earth was the predominant building material. In modern times, at least a third of the planet’s population lives in earthen houses. The task of providing the necessary construction materials is proving to be quite difficult, even in highly developed countries. Moreover, the irrational exploitation of resources and the elevated levels of production and consumption is not only a waste, but also a source of environmental pollution. In this context, we can talk about the earth as a naturally abundant material that could be the most important resource for construction. It can be both a low-cost building material, but also a material that can meet the current requirements for efficient, low-carbon emission and low-carbon footprint housing.</p> </abstract>ARTICLEtrue to Ensure the Quality of Construction Works for Marine Platforms with Reference to Midia Gas Development Project - ANA Platform & Doina Well & Gas Treatment Plant -<abstract> <title style='display:none'>Abstract</title> <p>The Midia Gas Development Project is a new offshore gas project which has been developed and built in the last 30 year in the maritime territory of Romania. Once completed, it will have the ability to cover around 10% of gas needs of Romanian population.</p> <p>Currently there is about 10 Bcm of resources to be produced at a rate of about 1 Bcm per annum.</p> <p>The infrastructure was thought to be used for the production of gas from the reservoirs of Ana and Doina, in the first place. But the long term vision of the project consists in converting the already existent infrastructure to develop green energy projects, such an offshore wind plant, solar panels fields or production of hydrogen, projects that may start time before decommissioning of the gas production platform.</p> </abstract>ARTICLEtrue Concerning the Dynamics of Footbridges and Methods for Improving Pedestrians’ Comfort<abstract> <title style='display:none'>Abstract</title> <p>Pedestrian bridges are constructions that are part of the category Bridges, having the particularity that due to much lower loading as compared to that of road or railway bridges, their decks are much slenderer, and can be included in the category of light structures. In this paper several aspects regarding the dynamic behavior of the footbridge structures under the traffic actions correlated with the pedestrians’ comfort are presented. The comfort criteria depend of the frequencies and accelerations of the structure and have to be situated between certain limits. If the frequencies and accelerations of the structure are in the critical domains, measures to modify them have to be taken, some of them being presented in this paper as they are the most usually used.</p> </abstract>ARTICLEtrue Earth as a Construction Material<abstract> <title style='display:none'>Abstract</title> <p>Traditionally, the greatest weaknesses of earthen constructions are water infiltration and freeze-thaw cycles. The purpose of this article is to analyze the characteristics of the soil in order to use it as a building material and the ways to improve it using various additives in the mixture or the possible treatment of exposed surfaces.</p> </abstract>ARTICLEtrue Economy and Strategic Management of the Construction Company<abstract> <title style='display:none'>Abstract</title> <p>One of the EU’s main priorities is sustainable development, which imposes the leading concept of a circular economy - an alternative economic model of the traditional linear economy. This poses new challenges to the company and managers and requires significant changes in strategic management, aimed at building competitive advantages by creating, offering and realizing additional economic, social and environmental value for the client, stakeholders and society as a whole. From this point of view, the research aims to: 1) Develop a model of strategic management - relationship between the circular development and the building of competitive company advantages, 2) Empirical study of the indicated connections and dependencies in the model and the influence on the process of building competitive advantages in companies operating on the construction market.</p> </abstract>ARTICLEtrue of Friction Dampers on Seismic Response of Steel Frames<abstract> <title style='display:none'>Abstract</title> <p>This paper deals with effect of friction dampers on seismic response of 2D steel frames in comparison with structures stiffened by large sections and centrally braced. For the present study three structures with six storeys are subjected to a time history analysis. To study the effect of dampers in structures in comparison with structures stiffened by large sections and centrally braced, are analysed the relative level displacements, maximum displacement on the top, variation of lateral acceleration at the last level and variation of the maximum seismic base shear force depending on the lateral rigidity. The results indicate that placement of friction dampers improve the response of structures in all analyzed terms.</p> </abstract>ARTICLEtrue the Fractal Characteristics of Some Meteorological Extreme Series Recorded at Constanta, Romania<abstract> <title style='display:none'>Abstract</title> <p>The study of hydro-meteorological series is important for planning agricultural activities, managing water resources, and taking measures to prevent the effects of natural hazards. Therefore, here we analyze the fractal characteristics of the temperature series recorded at Constanta, Romania. The studied series are the annual mean maximum annual and minimum annual temperatures recorded during 1961-2018.</p> </abstract>ARTICLEtrue and Procedures of Analysis Applicable in the Evaluation of the Archaeological Heritage<abstract> <title style='display:none'>Abstract</title> <p>The implementation of the European policy in the field of built heritage involved, for each country, the creation of the legal, administrative and financial means necessary for the implementation of the rehabilitation policy. The research procedures and the intervention measures must be correlated with the degree of damage (degradation) of the materials, as an effect of earthquakes that the construction has endured, of others specific exploitation actions, differential land settlements, uncontrolled human interventions or environmental factors. Archaeologists around the world have developed a procedure for evaluating archaeological resources, so it appeared in the early 1970s, an example being that developed by Schaffer and Gumerman in 1977. Archaeological sites have the ability to demonstrate how the society functioned at a given time, the level of civilization, the progress of science and technology, what processes have taken place, how the activity unfolded and the extent of a technological practice or other occupation history. They can demonstrate the main characteristics of a place or process that may be rare or common. In the article, the authors develop the principles that lie at the base of quantifying the values of archaeological heritage, presenting some case studies.</p> </abstract>ARTICLEtrue and Simulation for Optimization of a Ventilation Installation Using Artificial Intelligence<abstract> <title style='display:none'>Abstract</title> <p>In this article we present the way how to create a program in the Scilab-Xcos environment with which it can be dimensioned, mathematically modeled and simulated a ventilation installation using artificial intelligence for its implementation.</p> <p>The mathematical equations implemented in the program with which the dimensioning and simulation are done are presented.</p> <p>A neuro-fuzzy system was used to generate the fan characteristics.</p> </abstract>ARTICLEtrue Regarding Movila Verde-Independenta Water Supply Duct Protection from Water Hammer<abstract> <title style='display:none'>Abstract</title> <p>In the context of sustainable development effort, the water supply systems in the rural area of Constanta County should be optimally designed, so that their safe, efficient operation is assured. The results obtained by numerical simulation showed that Movila Verde -Independenta water supply duct might be subject of cavitation occurrence during hydraulic shock. Further investigations showed that the duct is adequately protected by a relatively short closing law of the check valve and three air valves mounted in the nodes where cavitation might occur. Minimal pressure increases from -10 mwc to -0.6 mwc because of these protection measures. Furthermore, the slight increase of maximal pressure does not require additional protection devices.</p> </abstract>ARTICLEtrue of Adapting Building Materials and Constructive Solutions to the Present Climate Changes<abstract> <title style='display:none'>Abstract</title> <p>The changes occurred on the climate are a reality that produces changes within the socio-economic environment. Climate change is largely due to greenhouse gas emissions generated by human, domestic and economic activities. In this climate, the constructive solutions of buildings must take into account climate changes and meet new requirements. In this context, building materials must improve and correspond to the new paradigm so as to fulfill their basic role, namely:</p> <p><list list-type="custom"> <list-item><label>-</label><p> creating an indoor climate corresponding to the hygienic-sanitary and thermal,</p></list-item> <list-item><label>-</label><p> comfort requirements in residential and socio-cultural buildings,</p></list-item> <list-item><label>-</label><p> ensuring the necessary indoor climate for carrying out economic activities reducing, as much as possible, the energy consumption for space heating.</p></list-item></list> </p> </abstract>ARTICLEtrue Study on the Urban Redevelopment of Ovidiu’s Shoreline<abstract> <title style='display:none'>Abstract</title> <p>This study adds to what most studies lack in understanding the process and context of urban regeneration. Only by understanding the local, national, and global contexts and processes of urban regeneration can inferences, lessons, and best practices be made. The objective of this study is to review the literature on urban regeneration and evaluate contemporary alterations and their implications for future city renewal. The rehabilitation of Ovidiu’s waterfront is a unique issue, considering the city’s location, its openness to Lake Siutghiol, which is separated from the Black Sea by only a 400m wide cordon, and the presence of the Roman camp and the aqueduct that previously supplied the Roman castle of Tomis. Lake Siutghiol has considerable growth potential due to the direct connection between Ovidiu and Mamaia, a popular tourist destination recently attracting many investors.</p> </abstract>ARTICLEtrue Green and Digital Transformation - the New Challenges of the Construction Market<abstract> <title style='display:none'>Abstract</title> <p>The new EU industrial strategy proposes new measures to strengthen the sustainability of the European single market (especially in times of crisis) and to accelerate the green and digital transformation. It focuses on 14 industrial ecosystems (one of which is construction), which face the most important challenges of achieving the climate, sustainability and digital transformation goals that are key to market competitiveness. The purpose of the study is: 1) Analysis of the problems related to the need to accelerate the green and digital transformation of the construction market, 2) Development of models that support and ensure the double transition in the construction market.</p> </abstract>ARTICLEtrue Regarding the Establishment of the Location for a Residential Building in the Project phase Based on Energy Consumption<abstract> <title style='display:none'>Abstract</title> <p>In this paper we propose to present the analysis of energy consumption for heating for a building in the design phase depending on the conditions of location in the field. We analyzed 3 variants of the location of the building. Establishing the location of the location for a building according to the estimation of energy consumption in the project phase is in accordance with the requirements established in Directive 2010/31 / EU. Design decisions can also have an impact on land use, resource use and the production of waste and emissions throughout the life cycle of the building.</p> </abstract>ARTICLEtrue and Vulnerability in the Analysis of Apartment Buildings<abstract> <title style='display:none'>Abstract</title> <p>The real estate funds in Romania in the category of condominiums presents an important subject to be analyzed after several considerastions. Securing apartment buildings raises issues of high complexity. The present study focuses on the presentation of the criteria of analisys, the earthquake as a degradation factor of these buildings, the evolution of norms regarding seismic actions concluding with an important study case building – the Simu apartments block in Bucharest. The authors also synthesized information from several publications over time in Romania.</p> </abstract>ARTICLEtrue