Joanna Dulińska

In this paper the experimental and numerical results of dynamic characteristics (i.e. natural frequencies and modes of vibrations) of the cable-stayed footbridge, located in Czestochowa, are presented. The numerical analysis was carried out with the ABAQUS package. The in situ tests methodology and the results are also presented on the basis of the spectral analysis of vibrations caused by a group people jumping. The theoretical and experimental results are in good agreement as far as both the natural frequencies and eigenmodes are concerned.

In this paper, the dynamic analysis of three footbridges that carry pedestrians over the S7 national road ‘Zakopianka’ are presented. Firstly, the dynamic characteristics of the structures were evaluated. It transpired that the lowest natural frequencies of the two selected objects coincided with the pacing frequencies of a running pedestrian. Hence, the dynamic responses to this kind of dynamic loading were calculated and the comfort criteria were assessed.

This paper presents an analysis of the dynamic response of an overground steel pipeline during a strong mining shock. The analysis was conducted using various calculation methods- a time history (THA), a response spectrum (RSA) and a multiple support response spectrum analysis (MSRS). For the THA and MSRS methods, non-uniform effects of ground excitation were taken into account. During the analyses, the bending moment was calculated. On the basis of obtained results, it can be noted that the non-uniform effects had a significant impact on the dynamic behaviour of the pipeline and it was indicated that the MSRS method led to more accurate estimation than the RSA.

In this paper, the dynamic response of an overground steel pipeline to a real mining shock is presented. The submodeling method was used in the calculation. Firstly, time history analysis of a simplified beam model of the pipeline (a global model) was conducted. Secondly, the 3D model of a part of the structure over the support was created (a submodel). The submodeling analysis allowed obtaining stress distribution in the bolted connection of the pipeline segments.

This paper investigates the dynamic performance of a concrete bridge under a sequence of earthquakes. The PGA of the mainshock and the aftershock were comparable. The concrete damage plasticity model of material was assumed to represent the plastic behaviour of the bridge. Firstly, the mainshock was applied to the bridge, then the aftershock was imposed on the structure which had already been weakened by the first shock. The analysis of plastic and damage measures revealed that the aftershock had a considerable effect upon the structure in terms of enlarging zones affected by irreversible strains or additional damage evolution.

The dynamic analysis of a fifty-meter-long arch footbridge built in Poland is presented in the paper. The investigation focused on the comparison of dynamic responses to different types of dynamic loading, specifically pedestrian movement, traffic loads, mining tremors and seismic shocks. The FE model was created in the ABAQUS software. It transpired that the vibration level exceeded the thresholds ‘slightly felt’ in case of both, pedestrian and traffic loadings. The results also suggest that the safety of the structure is not threatened by this level of mining and seismic vibrations.