The effect of stiffness and duration parameters to the service life of the pavement structure

The goal of this article is to determine the effect of various material parameters to the fatigue life of the pavement structures. Nowadays many types of mixtures can be built in the pavements, with different stiffness moduli. However, the Hungarian asphalt pavement design method can not handle that. The main cause of failure of the asphalt layers is supposed to be caused by the strains coming from the horizontal tensile stresses at the lowest level of layers. Many calculations were made with various attributes of the layers of the pavement structures i.e. subgrade, base course, binder course and surface course. After these calculations, we can clearly see which parameter of which layer is the most important to build a pavement with long fatigue life

Experimental Investigation on Condition Monitoring Opportunities of Tramway Tracks

The increasing demands for guided transportation modes in urban areas generate the need of high-frequency services. Due to the frequent services, the track deterioration process will be accelerated. Therefore, the exact knowledge of track quality is highly important for every railway company to provide high quality service level.For monitoring of tramway tracks, an unconventional vehicle dynamics measurement setup is developed, which records the data of 3-axes wireless accelerometers mounted on wheel discs of regular in-service tram. In the implementation of prototype system, the bogie side-frame and car body mounted sensors are also fitted to the instrumented vehicle to compare the efficiency of these conventional solutions with the developed arrangement. At the first test period, the instrumented vehicle works as a dedicated inspection vehicle, in order to keep the constant velocity and help to determine the influencing factors on results. Accelerations are processed to obtain the track irregularities, in order to determine whether the track needs to be repaired. Real data come from measurements taken on tram line 49 of the Budapest (Hungary) and they have been validated by comparing results to the actual state of the track provided by a track geometry monitoring trolley and visual inspection. This paper presents the developed methods used for validation and the analysis of preliminary results of the wheel discs mounted accelerometers. This vehicle dynamic measurement system is cheap to implement and no significant modification of the vehicle is required. Therefore, in-service vehicles equipped with this system may serve a good opportunity for monitoring tramway track, while it multiple passes over same track section

Etraffic – an Open Access Transportation Model

This paper presents a modular transportation modellingapproach. In the proposed system travel demand is determinedusing existing statistics. All data describing a national roadnetwork and corresponding traffic demand is loaded into thesoftware application, consisting of a web interface and manageddatabase. Users have access to this dataset and mayfreely modify it to create their own models and scenarios fortransportation studies

A practical approach to tramway track condition monitoring: vertical track defects detection and identification using time-frequency processing technique

This paper presents an automatic method for detecting vertical track irregularities on tramway operation using acceleration measurements on trams. For monitoring of tramway tracks, an unconventional measurement setup is developed, which records the data of 3-axes wireless accelerometers mounted on wheel discs. Accelerations are processed to obtain the vertical track irregularities to determine whether the track needs to be repaired. The automatic detection algorithm is based on time–frequency distribution analysis and determines the defect locations. Admissible limits (thresholds) are given for detecting moderate and severe defects using statistical analysis. The method was validated on frequented tram lines in Budapest and accurately detected severe defects with a hit rate of 100%, with no false alarms. The methodology is also sensitive to moderate and small rail surface defects at the low operational speed