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Collaborating Authors
croatia government
His research interests include the application of scientific computing and algorithm development. Dr. Jeričević received a B.S. in organic chemistry (1975) from the University of Zagreb, Faculty of Natural Sciences and Mathematics. He received an M.S. in molecular biology (1978), and a Ph.D. in chemistry (1984) from the Ruñer Bošković Institute and University of Zagreb, respectively. From 1985-1991 his positions were as a postdoctoral appointee, an instructor, and as an assistant professor. Dr. Jeričević worked for Western Atlas/Baker Hughes as senior research scientist from 1991 to 2003.
- Energy > Oil & Gas (1.00)
- Health & Medicine (0.82)
- Information Technology > Knowledge Management (0.40)
- Information Technology > Communications > Collaboration (0.40)
Daria Karasalihović Sedlar is full professor at the University of Zagreb, faculty of Mining, Geology, and Petroleum Engineering. She holds a PhD degree in petroleum engineering. Her scientific research relates to energy economics, natural gas sector management, geothermal energy potential assessment, and CCUS policy and development strategies. She is a member of the Council for Energy Transition of the President of the Republic of Croatia and an International Gas Union member. As an SPE student faculty adviser and SPE Education and Accreditation Committee member, she was involved in numerous SPE projects.
Shear Strength Determination of Very Rough and Partially Filled Extension Fractures in Thick-Bedded and Karstified Limestones
Hrženjak, Petar (University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering, Croatia) | Dobrilovic, Ivana (University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering, Croatia) | Navratil, Dražen (Croatian Geological Survey, Croatia) | Zelic, Biljana Kovacevic (University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering, Croatia)
ABSTRACT: Extension fractures that appear as very rough and irregular and with or without infill material, are common in thick-bedded and karstified limestones for which present-day methods for shear strength estimations are inappropriate. With the aim of determining the shear strength of such discontinuities, field research was carried out, in which large samples of blocks with discontinuities, as well as samples of filling material were prepared, on which then detailed laboratory tests were performed. Based on the obtained results, a modification of Barton's JRC-JCS empirical model was made in such a way that the friction angle of the built-in filling material in the case of discontinuity with a filling was applied, instead of the residual friction angle. In addition, the joint contact coefficient (JCC) was introduced as the measure of the actual contact area between discontinuity walls by means of which the normal stress on the discontinuity surface can be corrected. INTRODUCTION It is generally known that the process of karstification creates specific morphological forms of grounds such as: caverns, sinkholes, shafts, swallow-holes, karstic depressions, karstic fields, and plateaus. However, apart from the specific morphological forms of ground, the process of karstification can create specific morphological forms of discontinuity wall surfaces (Hrženjak et al. 2019). Through the process of karstification, a process of chemical weathering of carbonate rocks under the influence of water acting like a weak carbonic acid, the walls of certain discontinuities are dissolved, resulting in very irregular and rough surfaces with prominent irregularities on both a small and large scale. This is especially prominent in thick-bedded and karstified limestones with many extension fractures that can be very rough and irregular, with or without filling material, as is the case in dimension stone deposits. A typical example of a such situation is the "Kanfanar" deposit, in which underground exploitation of dimension stone was introduced by the room-and-pillar excavation method (Figure 1). "Kanfanar" is one of the biggest limestone quarries in Croatia located on the Istrian peninsula.
Abstract This paper describes how to use standard geotechnical equipment as a “gas pycnometer.” The presented “gas pycnometer” is used to determine the solid particle density (SPD) of mechanically and biologically treated (MBT) municipal solid waste (MSW). The measurements were made on waste samples obtained from Marišćina, a Croatian waste management plant. The average SPD value, obtained from 23 fresh samples, was 1.89 g/cm. In addition, 10 compacted and 3 shredded samples were also tested. Both compacting and shredding caused increases in the average SPD value to 1.91 and 1.93 g/cm, respectively. The obtained results show good agreement with the average SPD value for waste material based on results collected from the literature. The presented “gas pycnometer” has been proven to be a reliable, cost-effective, and quick solution for the determination of the SPD of MBT waste material.
Experimental research of soil - steel frame system on shaking table
Brandis, Adriana (Faculty of Civil Engineering and Architecture, Osijek ) | Ceh, Nina (Faculty of Civil Engineering, Rijeka) | Jagodnik, Vedran (Faculty of Civil Engineering, Rijeka) | Kraus, Ivan (Faculty of Civil Engineering and Architecture, Osijek) | Brandis, Denis (Ðakovoprojekt, Ðakovo)
Most of the researchers tend to lean thei studies on data obtained via experimental tests which can be carried out in the field or in the laboratories. When Table 1 is observed, it is possible to conclude that certain type of experiments is common when studying soil-structure interaction, namely: (i) centrifuge tests, (ii) shaking table tests, and (iii) in-situ tests. Models tested in geotechnical centrifuges are very valuable, but due to their small scale it is desirable to compare them with models tested in a larger scale since larger models allow the installation of greater number of instruments and have closer behaviour to real systems. Although large-scale experiments are encouraged, due to their high costs and laboratory limitations, they are not always possible. Considering all limitations, original experimental research of soilstructure interaction is planned and carried out by the authors. The main goal of the research was to investigate the impact of foundation soil flexibility on seismic behaviour of structures with shallow foundations through original experimental research on small scale models and parametric analysis.
- Europe > Croatia (0.30)
- Asia > Middle East > Israel > Mediterranean Sea (0.24)
- Research Report > New Finding (0.94)
- Research Report > Experimental Study (0.94)
Monitoring subsidence in Tuzla (BiH) by DInSAR and GNSS from 2004-2019
Grujic, Bojana (University of Banja Luka, Banja Luka ) | Parwata, I Nyoman Sudi (Yamaguchi University, Ube) | Shimizu, Norikazu (Yamaguchi University, Ube) | Celikovic, Ruža (University of Tuzla, Tuzla) | Imamovic, Edis (Municipality of Tuzla, Tuzla) | Zekan, Sabid (University of Tuzla, Tuzla) | Vrkljan, Ivan (University of Rijeka, Rijeka)
Abstract The underground salt mine in Tuzla, Bosnia and Herzegovina (BiH) has caused one of the most serious ground subsidence problems in Europe. The mine was closed from 2006-2007 by means of filling the salt mine rooms with water. However, the subsidence still continues over some parts of the city. This paper presents the recent measurement results together with the previous results, i.e., 2004-2007 by GNSS, 2007-2013 by GNSS and geodetic surveys, and 2014-2019 by GNSS and DInSAR. The time transition for the subsidence obtained by DInSAR shows a good agreement with the monitoring results by GNSS. It is found that the subsidence in Tuzla is still on-going at a rate of 1-4 cm/year in the eastern area of the salt deposit. In a hilly section of the eastern area, a dominant horizontal displacement was detected by GNSS surveys. It is concluded that the combination of SBAS-DInSAR, GNSS, and geodetic surveys will be effective for monitoring both subsidence and landslide behavior.
- Europe > Bosnia and Herzegovina (0.74)
- Europe > Croatia (0.47)
- Geology > Mineral > Halide > Halite (1.00)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
Geophysical investigation works for the needs of pile foundation of wind turbine tower, Case study of wind power plant Bruvno (Croatian)
Strelec, Stjepan (University of Zagreb, Varaždin) | Jug, Jasmin (University of Zagreb, Varaždin) | Golub, Ivan (University of Zagreb, Varaždin) | Kranjcic, Nikola (University of Zagreb, Varaždin)
The PDF file of this paper is in Croatian. _ Abstract Wind power plants are developing rapidly in the Republic of Croatia and in the world, since they represent one of the renewable energy sources. Croatia has many areas that have satisfactory wind potential for the construction of wind power plants. In Croatia, wind power plants are most often built in Dalmatia. Due to the complex geological structures and differences in the soils, it is necessary to perform field investigations in order to determine the properties of the underlying soil, which ensures the quality of construction of the wind farm. Field geotechnical and geophysical investigations at the construction site of the Bruvno wind power plant near Gračac in the Republic of Croatia were carried out for the purposes of the foundation of the wind turbine towers and the foundation of the transformer station. Field investigations include exploratory boreholes, and geophysical investigations using geoelectrical tomography, georadar surveys, and seismic investigations using multichannel analysis of surface waves (MASW). The goal of the research was to collect data on the general and mechanical properties of the foundation soil to determine the optimal foundation conditions, bearing capacity, settlement and mechanical stability. This paper presents an overview of the mentioned methods along with a presentation of the results of each method at selected locations.
Some physical properties of soil used in traditional Croatian rammed earth houses
Kaluder, Jelena (Josip Juraj Strossmayer University of Osijek, Osijek) | Kraus, Ivan (Josip Juraj Strossmayer University of Osijek, Osijek) | Peric, Ana (Josip Juraj Strossmayer University of Osijek, Osijek) | Mihic, Ivana Brkanic (Josip Juraj Strossmayer University of Osijek, Osijek)
Abstract In eastern Croatia, houses were traditionally built using soil as the building material. The construction of rammed earth houses is carried out in layers within the formwork, and the choice of suitable soil depends on several properties, such as particle size distribution and plasticity. Unfortunately, the construction and renovation of such houses is almost non-existent nowadays since there are no regulations and recommendations for construction in Croatia. With the aim of forming recommendations, soil samples were collected from existing houses in order to test the physical properties of the soil. The comparison of obtained results with those published in literature and published recommendations, showed that bulk density and Attbereg limits are within the limits of the published values. However, particle size distribution differs from most recommendations and published results. Further research on soil properties from existing houses is needed in order to make recommendations for the area of Eastern Croatia.
Abstract Landslide investigations often are based on exploratory or rotary core drilling, which has its drawbacks. Borehole investigations are expensive and long term. It is a kind of point test so that important soil layers can remain undetected by drilling. Inaccessible and steep terrains on landslides are often a significant problem for drilling rig applications. Therefore, in recent years, this standard investigation method has been supplemented or, in specific cases, replaced by modern methods of geotechnical and geophysical investigations. This paper presents just such a case of landslide investigation without the application of exploratory drilling. The investigations were carried out in village Petrovsko (north-western Croatia), on a landslide of the rotational-translational type, with a total area of 5000 m. This instability potentially threatened the D206 state road corridor. Engineering geological and recent geotechnical-geophysical investigations were applied to define the boundaries of instability, the lithological composition of sediments in the subsurface and locating the sliding surface. According to the results of investigations with a Dynamic Probe Light (DPL) and Cone Penetration Test (CPTu), the depth of the sliding surface was determined. Geophysical investigations performed using Electrical Resistivity Tomography (ERT), Seismic Refraction (SRF) and Multichannel Analysis of Surface Waves (MASW) confirms and perfectly complement the results of in situ geotechnical surveys. The unfavourable geological structure was determined, as silty sands and clays predominate in the surface layers, and organic clays of low shear strength appear immediately before contact with marl. The main cause of landslides is the decreased strength of clay in contact with marl, due to the rise of ground water level and effect on pore pressure and effective pressure of the deeper layers of the clay. Finally, the gravel drainage trenches have been proposed as a conceptual remedial solution through the upper lying layers to hard marl.
- Geology > Rock Type (0.68)
- Geology > Geological Subdiscipline > Geomechanics (0.35)
The PDF file of this paper is in Bosnian. _ Abstract All parameters necessary for settlement calculation of a simple soft rock homogenous embankment were determined using appropriate laboratory methods, on the example of a typical Dalmatian soft rock (marl). Laboratory simulation of marl weathering was used for the test sample preparation and is described in detail. In addition, naturally weathered material was taken from the talus of an abandoned cut and also used in the research. Standard and modified Proctor tests were performed on both materials, as well as oedometer tests for material consolidation properties. The obtained results were used for a settlement calculation of a simple homogeneous embankment with a height of not more than 15 m. Total settlement values were compared for different embankment heights, different compaction variations and different preparation methods of construction material (natural or laboratory simulated weathering).
- Materials > Construction Materials (0.54)
- Health & Medicine > Diagnostic Medicine > Lab Test (0.40)