In this paper, the author’s research work is focused on infrastructure impact on railway transportation system reliability. The aim of research described in the paper is to determine correlation between type (and age) of used infrastructure elements, and number of occurring failures. For this purpose, subsystem of infrastructure and associated with it events, were divided into main groups. Examples of groups are: track, train operation devices (related to operating control points or railway line), level crossings, etc. The second aspect is correlation between type of infrastructure and failure consequences. It is required from transportation that it is possible to achieve the right place at the right time in a safety way. Therefore, from the point of view of transportation process, which is the main goal of transportation system, the most significant failure consequences are delays. Moreover, speaking about reliability and safety of railway transportation system, the question arises what is the relation between number of trains and number of unwanted events?
Prediction the Bearing Reliability on Basis Diagnostic Information
The new complex method of diagnostics of helicopter's turbine engine Allison 250 in work was. This method be bases on complex diagnostic signals of resulting with simultaneous use three autonomic methods of diagnosing (functional diagnosing, wibroacustic diagnosing and tribologic diagnosing) and of surroundings described with number of crossings of diagnostic sill timbers of these signals. This way of description permits to establish between diagnostic signals quantitative reports and the surroundings and the state of technical object. It the diagnostics was conducted of arrangement bearings two engines Allison 250 built-up on helicopter PZL - KANIA. It was showed, that captured in this way diagnostic signals can be used to prediction of reliability profiles of arrangement bearings.
The Bistrita city bypass crosses obliquely at km 14+162 the Bistrita river and a local road. In the area where the bridge is situated the river has a width of about 50.00m and the local road has 5.00m, being located at 12.00m from the bank of Bistrita. The bridge should provide a roadway that is 7.80m wide and two sidewalks of 1.50m.
The challenge is to design a bridge that allows the crossing of the two barriers (the river and the local road) in the most efficient way possible from an economical point of view, but in such a way that both the geometrical constraints and the design requirements contained in the family of the European standards Eurocodes are respected.
In order to achieve this goal, the author has investigated the design situation by comparing different possible technical solutions, by conducting a series of parametric studies and by utilizing mathematical optimization techniques.
Following these investigations a 100.00m long bridge resulted. The superstructure is a continuous beam with three spans: 20.00m + 60.00m + 20.00m and consists of a composite steel - concrete deck. The deck cross section is composed of two steel beams with variable height and a reinforced concrete slab disposed on top. This configuration of the superstructure leads to the development of negative reaction forces in the bearings located at the end points of the deck.
The study has covered 8 key steps as follows:
- Establishing the technical solution.
- Establishing the number and the length of the spans.
- Setting the static scheme.
- Determining the optimal cross section of the steel beams.
- Setting longitudinal beam geometry.
- Establishing the number of beams in the cross section.
- Determining the optimal mounting order of the concrete slabs.
- Establishing the optimal type and distribution of the bearing devices.
Loreta Levulytė, David Baranyai, Ádám Török and Edgar Sokolovskij
-Signalized Locations, Accident Analysis and Prevention 81 (0): 14-23. doi:10.1016/j.aap.2015.04.025.
12. Liu, Y. Ch.; Tung, Y.Ch. (2014) Risk Analysis of Pedestrians’ Road-Crossing Decisions: Effects of Age, Time Gap, Time of Day, and Vehicle Speed, Safety Science, 63 (0): 77-82. doi:10.1016/j.ssci.2013.11.002.
13. Mitsakis E., Stamos I., SalanovaGrau J., Morfoulaki M. (2015) Bus Drivers Risk Perception of Roadway Hazards.Period. Polytech. Transp. Eng., (43)1:15-21, DOI: 10.3311/PPtr.7481
14. Mueller, N., Rojas-Rueda, D., Cole
In this paper, controlling and optimizing against the earthquake by using genetic algorithm is investigated. In this paper, a new approach for selecting optimal accelerograph and scaling them for dynamic time history analysis is presented by the binary genetic algorithm and natural numbers, in order to achieve the mean response spectrum, which has a proper matching and a short distance with the target spectrum and indicates the expected earthquake of the site. Because of the difference in the nature of accelerograph and the scale coefficients, the genetic algorithm presented in this paper, is hybrid (has two chromosomes). The proposed algorithm is capable of constructing a new generation of people from a series of infinitesimal earth movement records, in a process where natural selection, mating, mutation takes place, and creates a new generation of people and continues this process until a person with desirable qualities is obtained. One of the most important factors in the accuracy and efficiency of these programs is the correct estimation of their parameters. If these parameters are correctly calculated, the difference between the mean response spectrum and the spectrum of the plot will be greatly reduced. Due to the relatively large number of these parameters, the use of trial and error-based methods largely relies on user skills, the proposed hybrid genetic algorithm program can overcome this defect. The program has two genomes that run simultaneously and provide close answers to the optimal answer. The program itself is able to provide the user with a range of optimal coefficients and crossing values and mutations of each chromosome.
În cadrul articolului cu titlul „Beton monolit versus beton prefabricat la execuția în consolă a podurilor” vor fi abordate o serie de probleme care apar atât la proiectarea cât şi la execuţia structurilor de poduri din beton precomprimat utilizând metoda execuţiei în consolă.
Această metodă a revoluţionat podurile din beton, din punct de vedere al deschiderilor şi al uşurinţei traversării unor obstacole dificile. În afara avantajelor realizării unor structuri din beton monolit prin execuţie în consolă, utilizarea elementelor prefabricate conduce la micşorarea semnificativă a timpului de execuţie şi la diminuarea problemelor care pot apărea din cauza curgerii lente şi a contracţiei betonului.
Materialul prezentat în cadrul articolului cu titlul „Beton monolit versus beton prefabricat la execuția în consolă a podurilor” va prezenta principiul metodei de execuţie în consolă, avantajele utilizării acestei metode, cazurile particulare pentru care se pretează o astfel de structură, scheme statice şi secţiunile transversale adoptate pentru acest tip de structuri, cât şi modul de îmbinare al tronsoanelor prefabricate în funcţie de generaţia din care fac parte.
De asemenea, se va prezenta un studiu de caz în care vor fi analizate cele doua variante de execuție în consolă (turnare monolită a tronsoanelor respectiv montare de tronsoane prefabricate) și vor fi prezentate concluzii privind oportunitatea utilizării uneia dintre cele două variante.