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A hydraulic excavator is widely used in crushed stone quarries to perform many different operations. Previous research on material handling by excavators is most often based on laboratory testing and observation of soil materials and the digging forces in them. These results are very difficult to transfer to fieldwork during the quarrying process. Therefore, in this work, the energy consumption of an excavator while working in typical materials for a crushed stone quarry was investigated. The field measurements were performed on overburden, blasted rock material, boulders, and two different crushed materials. Energy consumption was observed only during the portion of the cycle in which the bucket digs the material. In this way, the energy consumption was mainly related to the properties of the material. The highest energy consumption was found for blasted rock material, lower in overburden, and the lowest for boulders and crushed materials. These results are important for organizing an optimal distribution of machines according to the work tasks in the quarry and ultimately for energy savings.

After the adoption of the National Program for the Implementation of the Strategy for the Management of Radioactive Waste Used Resources and Spent Nuclear Fuel, by the Government of the Republic of Croatia, the issue of radioactive waste management in Croatia became current. Slovene-Croatian co-ownership over the Krško nuclear power plant (KNPP) means that half of the operational and decommissioning waste, as well as spent nuclear fuel (SNF) belongs to Croatia. Until now, SNF has been kept in a pool at KNPP, and dry storage before disposal is also planned. A generic project of a SNF repository has been developed and has already undergone a second revision and review. The project idea involves site selection in both countries and the conceptual solution of the SKB-3V type in crystalline rock. This paper presents an estimate of the thermal-hydro-mechanical effects (THME) of the SNF repository in crystalline rock (granodiorite) of SKB-3V concept by developing a numerical model in the SIGMA/W, SEEP/W and TEMP/W software. Simulations have shown that it is possible to construct a SNF repository in the crystalline rocks of Croatia or Slovenia, that the generic repository project is well-designed and that a model of hydro-thermo-mechanical effects of spent nuclear fuel on the rock in Croatia/Slovenia can be produced, which proves the suitability of the rock mass for this purpose.

Geosynthetic clay liners (GCL) are manufactured hydraulic barriers consisting of mineral and geosynthetic components. They belong to a group of geosynthetic products whose primary purpose is to seal and they have been used in many geotechnical and hydrotechnical applications, landfi lls and liquid waste lagoons for quite a while. They are used in landfill final cover systems to prevent the infi ltration of precipitation into the landfi ll body and the penetration of gases and liquids from the landfill into the atmosphere and environment. Laboratory and fi eld research and observations on regulated landfi lls have proven the eff ectiveness of GCL as a barrier for the infi ltration of precipitation into the landfi ll body as well as the drainage of fl uid beneath the landfill. Due to the presence of high concentrations of gases in the landfill body, there is a growing interest in determining the efficiency of GCL as a gas barrier. It was not until the last twenty years that the importance of this topic was recognized. In this article, current GCL gas permeability studies, the testing methods and test results of gas permeability in laboratory conditions are described.

Engineered barrier systems are used in radioactive waste disposal sites in order to provide better protection of humans and the environment from the potential hazards associated with the radioactive waste disposal. The engineered barrier systems usually contain cement or clay (bentonite) because of their isolation properties and long term performance. Quality control tests of clays are the same for all engineering barrier systems. Differences may arise in the required criteria to be met due for different application. Prescribed clay properties depend also on the type of host rocks. This article presents radioactive waste management based on best international practice. Standard quality control procedures for bentonite used as a sealing barrier in radioactive waste disposal sites are described as some personal experiences and results of the index tests (free swelling index, water adsorption capacity, plasticity limits) and hydraulic permeability of bentonite (the paper is published in Croatian).

Bentonite, which is a mineral component of geosynthetic clay liners, has important physical and chemical properties that ensure very small hydraulic permeability. The main component of bentonite is a clay mineral called sodium montmorillonite whose very low permeability is due to its ability to swell. The deposits of bentonite are spread all over the world, however, only a very small number of those deposits satisfies all the quality and durability demands that must be met if the bentonite is to be used in the sealing barriers. Depending on the location of installation and their purpose, geosynthetic clay liners must meet certain requirements. Their compatibility with the prescribed criterion is confirmed through various laboratory procedures. Amongst them are tests examining the index indicators (free swell index, fluid loss index, and water absorption capacity). This paper presents results regarding the impact of laboratory air temperature and relative humidity of the testing area on the water absorption capacity. This is one of the criteria that bentonite must satisfy during the quality and durability control of the mineral component of geosynthetic clay liner (the paper is published in Croatian).

During the Great Zagreb's earthquake in 1880 consequences of the liquefaction have been detected at six sites in the vicinity of Zagreb as the occurrence of sand boils. Liquefaction takes place when loosely packed, water-logged sediments near the ground surface lose their strength in response to strong ground shaking. During the liquefaction, due to pore pressure buildup, water may be forced to the surface carrying sand particles through volcano-like sand boils. Important factor for liquefaction occurrence is the state of soil densification which relates to geological age of deposits. Results of the absolute dating of fossilized trees found in Sava's alluvium in the vicinity of Zagreb and the results of the penetration tests show that another earthquake with magnitude ≥ 6.3 can provoke liquefaction once again (the paper is published in Croatian).

Top and bottom liners are one of the key construction elements in every landfill. They are usually made as compacted clay liners (CCLs) composed of several layers of compacted clay with strictly defined properties or by the use of alternative materials such as: GCL – geosynthetic clay liner, BES – bentonite enhanced soils or bentonite/polymer mixtures. Following the state of the art experiences in the world, GCLs are used in Croatian landfills for several years, as well. Depending upon the location and the obeying function, GCLs have to fulfill certain conditions. A legislated compatibility criterion has to be proven by various laboratory tests. In the paper are presented the results of direct shear and chemical compatibility tests of GCLs as well as the results of permeability measurement of kaolin clay (the paper is published in Croatian ).