COMPARISON OF TRENDS IN RISK MANAGEMENT THEORY AND PRACTICES WITHIN THE CONSTRUCTION INDUSTRY
Abstract: This study considered the problem of understanding and use of risk management methods in construction projects and their representation in the literature and their practical application. Research of trends in risk management was conducted using studies from the EBSCO database that were published in the period from 1999 to 2015. The focus included the development of two terms, namely traditional and holistic approach to risk management as well as to uncertainty and opportunity management. The trend of leading standards in the field of project management, PMBoK and ISO 31000 indicated full support for the modernization of risk management that focused on the risks as well as potential opportunities in the project. The findings also revealed that the global practices continued to lack awareness of risk management and its benefits for project goals. A similar situation was found in Croatia by observing project management practices in two case studies, namely Project Zagrebačka obala in Rijeka and a Project of SEECEL Zagreb. Primarily, the lack of education and communication between experts are important issues requiring attention in practice and academics. It is necessary to gradually introduce standards over time to prepare for progress in managing uncertainties and adopting more holistic approaches.
ENVIRONMENTAL IMPACT ANALYSIS OF HEAVY METAL CONCENTRATIONS IN WASTE MATERIALS USED IN ROAD CONSTRUCTION
I.Netinger Grubeša; I.Barišić
Abstract: Use of solid waste in place of conventional materials in civil engineering structures preserves natural resources and energy and avoids expensive and/or potentially harmful waste disposal. Many studies are investigating the application of waste materials in civil engineering structures. However, in an effort to find out new areas of waste materials utilization, the environmental impact of the installation of such materials in building structures often remains neglected. This study focused on the environmental aspect of the application of currently investigated waste materials in Croatia with an emphasis on heavy metal content. Heavy metal concentration in steel slag, river sediment, and biomass ash was measured, and the possibility of their use in road construction in accordance with currently valid legislation was assessed.
ESTIMATION OF POLLUTANT LOAD IN DRINKING WATER PROTECTION AREAS OF SPRINGS SV. IVAN, BULAŽ, AND GRADOLE
R.Nemarnik; G.Volf; B.Karleuša
Abstract: In this paper, the estimation of pollutant load within the drinking water protection areas (DWPA) of springs Sv. Ivan, Bulaž, and Gradole in Northern Istria (Croatia) is presented. To estimate the pollution load, the spreadsheet tool for estimating pollutant load (STEPL) model was used. STEPL calculates loads of organic pollutants, nutrients, and suspended solids. For each analyzed spring total, specific and pollutant loads by each analyzed category are calculated. The results show that the greatest loads are caused by human activities. In addition, for the purpose of the analysis, two additional future scenarios are introduced; one describes the situation after the implementation of the first phase of the Istrian water protection system project, and the other that describes a possible future state where each agglomeration of over 100 inhabitants within the protected areas has an adequate wastewater treatment plant (WWTP).
FLOOD MODELING OF THE VUKA RIVER SECTION UPSTREAM OF ITS CONFLUENCE WITH THE DANUBE RIVER
D.Marić; I.Hrskanović; T.Dadić; L.Tadić
Abstract: In this paper, a section of the Vuka River from its confluence with the Danube River in Vukovar to 3 + 630 rkm was modeled. The possibility and size of floods in the surrounding area were analyzed for different return periods (2, 5, 10, 50, and 100 yrs). Although the high-water levels of the Danube River are lower than the terrain elevation of Vukovar, they cause backwater in the Vuka River and in its tributary, the Bobotski canal. In that indirect way, the surrounding area is endangered and the efficiency of drainage systems is reduced. The existing riverbed of the analyzed Vuka River section was digitalized based on a digital terrain model using the geographic information system (GIS) software ArcGIS and the HEC-GeoRAS toolbar. A mathematical model of the steady-state flow of the Vuka river section using the digitized riverbed was executed in the HEC-RAS software using different return periods. The obtained velocities and water levels were analyzed using HEC-RAS, and the sizes of the flooded areas were calculated and observed in ArcGIS.
APPLICATION OF “EINSTEIN'S RIDDLE” IN SOLVING CONSTRUCTION MACHINE ALLOCATION PROBLEMS
B.Dasović; M.Čorak; M.Galić; U.Klanšek
Abstract: “Einstein’s riddle” is a popular example of constraints satisfaction problem. Since its introduction, different forms and variations of the riddle have been presented. Regardless of the variant of the riddle, its solution is considered a tough challenge for humans. Researchers have developed and are still developing mathematical models, as well as computational simulation models for solving it. In this article, the authors have modified a previously published mathematical model and developed a computational spreadsheet model for solving the riddle, which provides a unique solution for the riddle. The model was also tested in a small- and medium-scaled form for solving constraint satisfaction problems regarding the allocation of construction machines. The authors have also highlighted the model’s limitations for solving such problems and made suggestions regarding necessary modifications in the model to solve more complex problems in the same domain.
EXPERIMENTAL RESEARCH ON LATERAL PRESSURE OF GRANULAR MEDIA WITHIN CLOSELY SPACED WALLS CONSIDERING DIFFERENT FILLING CONDITIONS
Abstract: This article presents the results of an original experimental research on the lateral pressure acting on closely spaced rigid walls at different angles of granular particle orientation to the horizontal line. Filling was performed at three different predominant angles of grain orientation with respect to the horizontal line: 0°, 45°, and 90°. The aim of the study is to determine the nature of the influence of the particle orientation achieved by filling on the characteristics and distribution of the lateral pressure. In the experiments, a composite medium, i.e. a mixture of quartz sand and flat shell particles in a volume ratio of 2:1, was used. The results of the experiments showed a significant difference in the lateral pressure at different angles of particle orientation. It was found that at an angle of 90°, the average lateral pressure was 44.2% more than that at an angle of 0°.
COMPARATIVE ANALYSIS OF STEEL AND ALUMINUM STRUCTURES
J.Peko; N.Torić; I.Boko
Abstract: This study examined steel and aluminum variants of modern exhibition structures in which the main design requirements include low weight (increased span/depth ratio, transportation, and construction) and durability (resistance to corrosion). This included a design situation in which the structural application of aluminum alloys provided an extremely convenient and practical solution. Viability of an aluminum structure depends on several factors and requires a detailed analysis. The overall conclusion of the study indicated that aluminum can be used as a structural material and as a viable alternative to steel for Croatian snow and wind load values and evidently in cases in which positive properties of aluminum are required for structural design. Furthermore, a structural fire analysis was conducted for an aluminum variant structure by using a zone model for realistic fire analysis. The results suggested that passive fire protection for the main structural members was not required in the event of areal fire with duration of 60 min.
DEVELOPMENT OF TRAM TRAFFIC IN THE CITY OF OSIJEK
S.Dimter; Z.Tanasić; M.Zagvozda; F.Ruška
Abstract: The need for the introduction of trams in Osijek in the late 19th century was largely due to the poor connectivity between the areas of the city and the growing development of the city. Tram transport was an extremely important step in connecting and modernizing the city and a key step in the integration of the still unconnected areas of the city, a role it has played throughout history. From its beginnings, the residents of Osijek have been intricately connected to the tram, which has had a role in the modernization of the city and is today regarded as a symbol of the city. As a means of public transport, in Croatia, the tram is now used only in Zagreb and Osijek. Today, many cities around the world have reintroduced trams as a public transport system, and Osijek is one of the few “small” cities that can boast of its continuous existence and expansion. This paper describes the development and current state of tram traffic in Osijek as a contribution to the celebrations of the anniversary of the introduction of the electric tram in the city.