This paper studies the two widely used material models for predicting the dynamic behavior of soils, the Ramberg-Osgood and Hadrin-Drnevich models. Resonant column and torsional simple shear test results on dry sand were used to calibrate and evaluate the model built in the finite element software Midas GTS NX. Both material models are already implemented by the software. This study estimates the ability and efficiency of both soil models coupled with the Masing criteria to predict the behavior of soil when subjected to irregular loading patterns, (e.g., earthquakes), and measure the two most important dynamic properties, the dynamic shear modulus, and the damping ratio.
Authors:Zuzana Sabová, Zuzana Németová, Tatiana Kaletová, and Silvia Kohnová
The objective of the study is an assessment of a Ratka small water reservoir in Slovakia by using two main aspects, i.e., the hydrotechnical, geotechnical and environmental aspects.
An evaluation of the actual state of a small water reservoir was solved in a complex way. Based on the field measurements, the quality of surface water was controlled in order to check if the surface water quality indicators meet the requirements of government regulations. In addition to the terrain measurements, laboratory measurements were performed. The results assess the actual state of the small water reservoir in details, including an assessment of the water quality with proposed measures for improving the condition of the water reservoir.
Authors:Khawaja Adeel Tariq, Muhammad Sohaib, and Mirza Awais Baig
This research work is related to the study of effects on properties of concrete having rice husk ash as cementitious supplementary materials. Total four mixes of concrete were done with varying percentages of rice husk as 6%, 12% and 18%. The tensile, flexural and compressive strengths that contain rice husk ash were determined by testing cubes, cylinders and beams. There was a replacement of 6%, 12% and 18% of rice husk ash in all mixes except the control mix. The concrete's flexural strength with rice husk ash increases at the beginning and at the later age (i.e., 28 days) similar to control mix; however, variation in compressive and splitting tensile strength is negligible. The optimum results are achieved with 6% replacement of cement with rice husk ash. Therefore, it was inferred that rice husk ash could be used as partial replacement of cement in concrete to produce economic concrete.
Authors:Flóra Hajdu, Gabriella Lászlo, and Rajmund Kuti
In recent years, in order to increase the energy efficiency of older buildings in Hungary, several tenders have supported the modernization of the thermal insulation. Various thermal insulation materials have been installed on walls, on slab and on floor. Unfortunately there are cases where thermal insulation materials are not installed in accordance with the construction permit or the manufacturer’s instructions, which poses a serious danger in case of a fire. During the research the effects of heat on the behavior of Expanded PolyStyrene, a thermal insulation material often used in Hungary is examined. Laboratory tests and computer simulations were carried out, which are presented in detail in this paper. The aim of the research is to contribute to increase the fire safety of buildings.
With the rapid economic development, the original layout structure and spatial functions of the city have been affected. The purpose of this paper is to stimulate the potential and vitality of space through social interaction based on the analysis of activity behavior and traffic travel. Through communication in the existing leftover space, a living community with the purpose of spatial emotional connection is established or reconstructed. The social habits of residents have also undergone many adjustments and reorganizations. In this way, the degree of connection between people and space is deepened, to guide the public to actively participate in the adjustment of the characteristics of leftover space and space optimization, broaden the application boundary of space.
During the following research project, the effects of an electrically heated window on the thermal comfort parameters of permanently occupied spaces were examined. A thermal manikin and a Testo 400 comfort-meter were used for the tests. To characterize the space, the predicted mean vote and predicted percentage of dis-satisfied method was applied. The examination of the comfort indices took place in the vicinity of an electrically heated window glass. During the measurements the surface temperature of the glazing was changed, alongside the distance from the glazing at which the measuring instruments were set up. The project aimed to assess the results measured by the thermal manikin and assess the usability of heated window glazing, taking thermal comfort into account.
A calculation system has been developed to determine the optimum dimensions of asymmetric I-beams for minimum shrinkage. The objective function is the minimum mass; the unknowns are the I-beam dimensions; the constraints are the stress, local buckling, and deflection. Different steel grades have been considered (235, 355, 460 (MPa) yield stress) and other aluminum alloys (90, 155, 230 (MPa) yield stress). The material, the span length, the loading, and the applied heat input have been changed. It is shown, that using optimum design; the welding shrinkage can be reduced with prebending and can save material cost as well.
Authors:Milica Aleksić, Patrik Sleziak, and Kamila Hlavčová
A conceptual rainfall-runoff model was used for estimating the impact of climate change on the runoff regime in the Myjava River basin. Changes in climatic characteristics for future decades were expressed by a regional climate model using the A1B emission scenario. The model was calibrated for 1981–1990, 1991–2000, 2001–2010, 2011–2019. The best set of model parameters selected from the recent calibration period was used to simulate runoff for three periods, which should reflect the level of future climate change. The results show that the runoff should increase in the winter months (December and January) and decrease in the summer months (June to August). An evaluation of the long-term mean monthly runoff for the future climate scenario indicates that the highest runoff will occur in March.
Authors:Michaela Červeňanská, Dana Baroková, and Andrej Šoltész
During the flood situations in May and June 2010, the culmination of the Váh River and the Danube River was accompanied by the groundwater level rising in the Rye Island, in some boreholes even to their maximum measured levels. The increased groundwater level caused major problems, e.g. flooded cellars and underground spaces, contaminated drinking water in wells, flooded railways and farmlands. As a part of the research concentrating on the groundwater flooding phenomena in the Rye Island, the flood situation from the year 2010 was reconstructed, establishing the basis for a construction of the flood hazard maps and flood risk management plans. The problem was solved with a MODFLOW numerical model using the Groundwater Modeling System.
Nowadays, self-driving cars have a wide reputation among people that is constantly increasing, many manufacturers are developing their own autonomous vehicles. These vehicles are equipped with various sensors that are placed at several points in the car. These sensors provide information to control the vehicle (partially or completely, depending on the automation level). Sight distances on roads are defined according to various traffic situations (stopping, overtaking, crossing, etc.). Safety reasons require these sight distances, which are calculated from human factors (e.g., reaction time), vehicle characteristics (e.g., eye position, brakes), road surface properties, and other factors. Autodesk Civil 3D is a widely used tool in the field of road design, the software however was developed based on the characteristics of the human drivers and conventional vehicles.