Construction and Calibration of Portable Rain Simulator

The study of the methodology of measuring and monitoring the appearance of erosion processes is of great importance for the defining of conditions for the occurrence, development and prevention of erosion processes. Consideration of the mechanism of erosion processes simulations agents on the field and the possibility of determining the result of the changing parameters of land can provide critical value for the development process. This paper presents the construction and calibration of a portable field rain simulator, for the purpose of testing the mechanism of the occurrence of erosion processes in the area of Forest management “Lipovica” in the area of Belgrade. The construction of the apparatus is designed to simulate the conditions of natural processes and to provide complete mobility. It was performed the selection of a sprinkler that fulfills the low consumption criterion, with uniform coverage of the surface with the appropriate intensity. Three different types of sprinklers were tested. It was performed the calibration of the intensity of the simulated rain, its disposition over the surface, for three different slope angle, as well as the measurement of the diameter of the rain drop by the method of flour. The total simulated intensity is 4.7 l min-1, for the planned rainfall of 10 min, which corresponds to the duration of the intense downpour for the investigated area. The average rainfall drop diameter is 1.2 mm. Th e constructed and calibrated simulator corresponds to the set conditions of the experiment

Analysis of physico-mechanical characteristics of stone in Serbia for the needs of erosion control works

The area of Serbia is geologically very diverse and rich, which provides the possibility of exploitation, examination and application of various construction materials of non-metallic origin, which are obtained from solid, unbound and semi-bound rocks. As an essential construction material of non-metallic origin, which is applied in erosion control works, a building stone is distinguished. In Serbia, construction stone is used in erosion control works, primarily as a technical stone, and to a slight extent, as decorative (architectural stone). In order to adequately select and use the building stone, in the field of erosion control works, it is necessary to determine its mineral-petrographic, physicо-mechanical and special properties. The paper presents a comparative analysis of the physico-mechanical characteristics of the building stone in Serbia, originating from the hemogenic and organogenic sedimentary rocks, and the influence of the environment on the durability of the stone, with the primary goal of adequately selecting the construction stone for erosion control works.Подручје Србије је геолошки веома разноврсно и богато, што пружа могућност eксплоатације, испитивања и примене различитих грађевинских материјала неметаличног порекла, који се добијају од чврстих, невезаних и полувезаних стена. Као неизоставан грађевински материјал, неметаличног порекла, који се примењује у противерозионим радовима, издваја се грађевински камен. Грађевински камен се у Србији користи, у противерозионим радовима, пре свега као технички камен, а у незнатној мери и као украсни (архитектонски камен). У циљу адекватног одабира и употребе грађевинског камена, у области противерозионих радова, неопходно је утврдити његова минеролошко-петрографска, физичко-механичка и посебна својства. У раду је представљена упоредна анализа физичко-механичких карактеристика грађевинског камена у Србији, пореклом од хемогених и органогених седиментних стена, и утицаја услова средине на трајност камена, са примарним циљем адекватног одабира грађевинског камена за противерозионе радове

Analysis of Physico-Mechanical Characteristics of Building Stone for the Needs of Antierosion Works in Serbia

The area of Serbia is geologically very diverse and rich, which provides the possibility of exploitation, examination and application of various construction materials of non-metallic origin, which are obtained from solid, unbound and semi-bound rocks. As an essential construction material of non-metallic origin, which is applied in antierosion works, a building stone is distinguished. In Serbia, construction stone is used in antierosion works, primarily as a technical stone, and to a slight extent, as decorative (architectural stone). In order to adequately select and use the building stone, in the field of antierosion works, it is necessary to determine its mineral-petrographic, physico-mechanical and special properties. Th e paper presents a comparative analysis of the physico mechanical characteristics of the building stone, originating from the hemogenic and organogenic sedimentary rocks, with the primary goal of adequately selecting the construction stone for antierosion works in Serbia

Multiattribute prediction of terrain stability above underground mining operations

This paper is dedicated to the problem of stability prediction of the terrain above underground mining operations. After the initial introduction to the problem, then the short analysis of the model approaches used to solve it, and giving the algorithm for rock massif stability prediction, we describe the concept of the multiattirbute terrain stability prediction method. The application of the multiattribute prediction method for stability of the terrain above underground mining operations is presented on the example of the Brown Coal Mine Aleksinac. The used method is original, essentially different from the other methods of mathematical modeling, because its prognosis of the rock massif stability under the influence of underground mining operations is based on the balance of the stability indicators. Our comparative analysis of the results obtained by multiattribute prediction and the data obtained by measurements of real deformations and terrain settling in multiple mines shows high mutual correlation, with an average deviation of less than ±10%. These results are confirmed entirely on the example of the Brown Coal Mine Aleksinac

Construction and calibration of a portable rain simulator designed for in situ researches of soil resistance to erosion

Land degradation caused by erosion processes is a widespread global problem. A rain simulator is one of the tools often used to determine the resistance of soils to erosion processes. The aim of this publication is to present the process of construction and calibration of a small, portable field simulator which would be implemented in researches designed to determine the changes of soils’ shear strength parameters in forested areas (in situ) caused by the change of soil moisture content achieved by rain simulation. The constructed simulator consists of a metal frame, sprayers (with specific nozzles), a sediment funnel/tray made of metal, water and sediment collector unit, a water tank and pump, and a set of rubber hoses, manometer, valves, reducers, adapters and other supplementary equipment. The calibration was carried out by using the pluviometer method. The choice of nozzles was based on the criteria of low water consumption (losses), high uniformity coefficient (CU) and the possibility of achieving the intensity of downpour rains specific for the investigated area. Further calibration of the device consisted of determining the raindrop diameter and the distribution of rainfall when the simulator is positioned on slopes (7° and 15°). The achieved rain intensity was 1.7-1.9 mm.min-1 , with a uniformity coefficient (CU) of 92.23-93.70% for raindrop diameters (D50) equal to 1.2 mm. The kinetic energy of simulated rain (Ke) was 2.82∙10-6 J. The constructed simulator proved itself to be in accordance with all of the criteria given, and it can successfully be implemented in researches aimed to determine the resistance of forest soils to erosion processes, infiltration, and sediment yield

Primena potpornih konstrukcija u sanaciji klizišta na regionalnom putu Stolice - Krupanj

Landslides can be triggered by different factors including changeable weather conditions, prolonged heavy rains, complex terrain, traffic loads, etc. This paper deals with the problem of landslide rehabilitation on the Stolice-Krupanj regional road that resulted from vehicle loads and soil saturated with water. The technical measures used in the rehabilitation of the landslide included a concrete retaining wall and a geogrid-reinforced soil structure. Based on data related to soil obtained from laboratory tests, slope stability before and after applying rehabilitation measures was tested in the GEO5 Geotechnical software. The stability of the concrete wall was examined analytically by calculating the factors of safety against toppling and horizontal displacement. Both technical measures of given physicalmechanical properties increased the stability of the slope.Na pojavu klizišta mogu uticati mnogi faktori: promenljivi klimatski uslovi; velika količina padavina u kratkom periodu; složenost strukture terena; opterećenja od saobraćaja, itd. Rad se bavi problemom sanacije klizišta na regionalnom putu Stolice - Krupanj, koje je nastalo usled opterećenja od vozila i zasićenja zemljišta vodom. Tehničke mere koje su primenjene za sanaciju klizišta su: betonski potporni zid i potporna konstrukcija od tla i geomreže. Na osnovu podataka o zemljištu iz laboratorijskih ispitivanja izvršene su provere stabilnosti kosina pre i posle primenjenih mera sanacije u programu GEO5, dok je stabilnost betonskog zida ispitivana analitičkim proračunom faktora sigurnosti na prevrtanje i horizontalno pomeranje. Obe tehničke mere, zadatih fizičko mehaničkih karakteristika, povećale su stabilnost padine

Application of Simple Additive Weighting Method for Selection of Appropriate Measures in the Rehabilitation of the Landslide

Changeable climatic conditions, a large amount of precipitation in a short period, as well as the complexity of the terrain structure can affect the occurrence of landslides in many areas. The paper deals with the problem of landslide rehabilitation on the regional road Stolice - Krupanj, which arose as a result of the steep slope, soil water saturation, and traffic loads. The technical measures for rehabilitating landslides that have been analyzed are: concrete retaining wall, gabion retaining wall, and geogrid. Slope stability analyses with applied technical measures were performed in the GEO5 program. All technical measures have increased the stability of the slope. The final decision about the appropriate solution was made after ranking all alternatives and applying the Simple Additive Weighting (SAW) method. This Multi-criteria decision analysis method is used to find the sum of the weighted performance rating for each alternative on all criteria. The criteria used for the analysis are: С1 – Construction costs, С2 – Fitting into the environment, С3 – Lifetime of the object, С4 – Susceptibility to damage. The application of the SAW method also requires determining the weight of the criteria and for this was used Rank sum method. As a result of the application of the multi-criteria decision analysis method, the use of geogrid proved to be the best solution to prevent damage caused by landslides

Causes and effects of morphological changes of the regulated channel of the river Toplica

The regulation of small torrential watercourses outside the urbanized areas is often based on the so-called field type of regulation. In the selection of this concept, after the regulation works, the new channel is left to the natural process of the morphological formation of the water cross-section taking care not to disturb the general stability of the regulated channel. We present the process of morphological development of the regulated channel of the river Toplica, tributary of the river Kolubara, in the period 1982-2004 i.e. from immediately after the regulation works to the present day