No abstract

In Slovenia, torrent areas and forest roads are being regulated and built mostly in steep, erosion-prone areas. In addition to the geometry of extrapolated works, calculating bulk factors is key for estimating haulage masses. We have determined bulk factors for compact carbonate rock, mixed soil, and carbonate deposits. Each construction site was recorded with an unmanned aerial vehicle (UAV) before the excavation and after every 4±2 m3 of excavated material. The average point cloud density was 9535 points/m2. We processed the point clouds from each construction site and determined the difference in volume between the volume of excavated area and the volume of deposited material. The average bulk factor for compact carbonate rock is 1.42, 1.20 for mixed soil and 1.15 for carbonate deposits (calculated for fully loaded eight-wheeled truck). The calculated bulk factors for soils and carbonate deposits match with the already established values, while the factor for compact rock is 20% lower than the factor currently in use by the Slovenian forest engineers.

Improving subgrade strength can reduce a road's construction and maintenance costs. Additionally, it may lessen some of the environmental impacts from forest roads. However, most forest roads receive little effort to establish or control compaction because of the perceived increase in construction costs and potential delays in the flow of wood from the area. A light drop-weight deflectometer was tested on two forest roads in western Oregon to determine if this tool could aid with improving forest road construction by improving the quality of the road's subgrade. One road was built on a fine sand-silt soil and the other was constructed on a silt-clay soil. The goal was to correlate the easily collected subgrade values produced from the light drop-weight deflectometer and wet unit weight to the soaked and nonsoaked California bearing ratio (CBR) values for the subgrade, which are common design variables used to determine the minimum thickness of the aggregate surface. The light drop-weight deflectometer showed mixed results with regards to its ability to predict the values from the more expensive CBR laboratory test. The results from site 1, sand-silt soils, showed the potential of the light drop-weight deflectometer to aid in construction control as the values from light drop-weight deflectometer, when combined with the wet unit weight, explained a statistically significant amount of the variability in the soaked and nonsoaked laboratory CBR values. These variables explain approximately 60% of the variation in CBR values. The data from site 2, the silt-clay soils, were not able to significantly predict the subgrade strength variables, and the road will need to continue to use the traditional methods for establishing and controlling compaction.

IzvlečekNaraščajoče cene fosilnih goriv in doseganje nacionalnih ciljev na področju povečanja rabe obnovljivih virov prinašajo vse večje zahteve po uporabi naravnih potencialov. Slovenska zakonodaja zelo togo opredeljuje izkoriščanje sečnih ostankov in proizvodnjo zelenih sekancev. To v praksi omogoča precej stihijski razvoj storitev, kjer se z uvajanjem novih tehnologij odpira vrsta vprašanj predvsem glede obremenitev ekoloških dejavnikov. V prispevku je predstavljena metodologija za oblikovanje odločevalnega orodja za izbor ekološko ustrezne tehnologije pri proizvodnji zelenih sekancev, upoštevajoč različne ekološke in tehnološke dejavnike. Gre za tristopenjski metodološki pristop, kjer v prvem koraku opredelimo talne in terenske razmere, v drugem koraku tehnologije ob upoštevanju raznolikosti glede na gospodarske učinke in ekološko primernost, v zadnjem, tretjem koraku, izbranim tehnologijam določimo mesto v odločitveni matriki z upoštevanjem tehnološke in ekološke omejitve posameznih tehnoloških modelov. V prispevku je predstavljenih 13 poenostavljenih proizvodnih procesov, razvrščenih v odločevalno matriko, upoštevaje ekološke in tehnološke vidike pri proizvodnji zelenih sekancev.ključne besede: tehnološki model, proizvodnja, proizvodne verige, poškodba tal, zeleni lesni sekanci abstract Due to the rising prices of fossil fuels and promotion of renewable energy sources, we recently witnessed the growing demands of the public for the exploitation of renewable biomass potentials. Slovenian legislation very rigidly defines utilization of logging residues and the production of green chips. In practice, this allows uncontrolled actions that bring new technologies, which raises a number of issues particularly with regard to environmental and ecological burdens. This paper presents a methodological approach used at design of the decision-making tool for the selection of environmentally friendly harvesting system in the production of green woodchips by considering various ecological and technological factors. Basically, a threestep methodological process is used, where in the first step soil and terrain are defined, in the second step, harvesting systems taking into account the diversity in terms of economic impact and ecological suitability are proposed and, last but not least, harvesting systems are placed into decision matrix taking into account technological and environmental constraints of different harvesting systems. The article also suggests 13 harvesting systems that are arranged into decision-making matrix taking into account the ecological, technological aspects in the production of green woodchips.