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This paper presents a novel approach to the creation of a ranking list of bridges with the highest priority for repair, renovation or exchange. Two main aspects addressed herein are studied. First concerning parameters, which must be taken into account while creating the list of bridges with priority for repair or renovation. Second concerning proposition of algorithms for creating such list. A set of factors that affect this priority has been created; the three main ones were selected: technical condition factor, safety factor and the importance for the roads network factor. Three self-reliant algorithms of the ranking list creation are presented. One of them is the so-called “expert algorithm”, based on artificial neural networks – gives the best result and has been indicated as the recommended one. This algorithm, engaging back-propagation multilayer artificial neural network, is implemented in the General Directorate for National Roads and Motorways in Poland and is applied as a supporting tool in managing road-engineering structures.

The paper presents the results of vibroacoustic tests of a plate girder railway bridge consisting of two parallel dilated structures and a common ballast trough. The requirements currently set for railway bridges relate to, among others, vibrations considered as one of the criteria for traffic safety and to noise emissions that may pose a threat to the environment. In this article, the results of tests conducted on vibrations of elements of the analyzed structure are presented, and the level of these vibrations in terms of meeting the requirements of the European standards is assessed. Vibrating criteria of structure performance were checked, and safety was assessed. The results of noise measurements in the vicinity of the analyzed bridge are also presented, and the environmental impact of this structure is determined. The test results show that the bridge meets the requirements for vibration acceleration and noise. An increased acoustic emission in the analyzed case does not pose a significant threat, but if this type of structure was on high supports in an urbanized area, it would be a nuisance to the environment.

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The paper presents the results of a vibration damping analysis of two road viaducts. The analysis was based on displacement signals recorded during the dynamic load tests carried out before an acceptance process of the viaducts. To create an additional excitation, a 5 cm high threshold was located on the road during low-velocity passages. The Logarithmic Decrement (LD) was calculated using an exponential curve fit to free vibration amplitudes. A fundamental frequency of vibration was considered. To minimize the influence of signal imperfections, a filtration process was carried out using bandpass Infinite Impulse Response (IIR) Bessel filter. The results were correlated for various degrees of excitation resulting from different velocities of loading vehicles and the presence of the threshold. Examples of appropriate and inadequate signals for the damping analysis were shown.