The paper presents a dynamic analysis of the damaged masonry building repaired with the Flexible Joint Method. Numerical analysis helped to determine the effect of the applied repairing method on natural frequencies as well as values of stresses and accelerations in the analyzed variants of numerical model. They confirmed efficiency of the proposed repair method.

The paper presents the author’s approach to evaluating the dynamic resistance of existing building structures exposed to the action of paraseismic events. The idea of the approach was demonstrated in the example of an existing conveyor bridge, which is an important component of an industrial plant located in an area threatened by the occurrence of mining tremors. A scenario was analysed in which the object’s structure was not adapted to absorb additional dynamic effects. Therefore, it was necessary to determine the load-bearing capacity reserve within which the dynamic effects induced by a mining tremor could be allowed. As part of the analysis, criteria for selecting the authoritative section of the analysed object for further dynamic calculations were established and described in detail. As a result of the implemented evaluation procedure, the limiting values of the ground acceleration components were obtained, which are understood as the resistance of the analysed object in the context of carrying additional dynamic actions induced by a tremor. The determined resistance is included in the ultimate limit state STR framework, which sets the level of strength of particular structures’ components as a criterion. The limit values of the ground acceleration components were calibrated, taking into account other accompanying variable actions according to the Eurocodes guidelines. The study also justified using this approach and provides essential information about dynamic excitation’s most sensitive structural components. Such information can direct the process of retrofit or necessary strengthening of the structure when the evaluated resistance will exceed the intensity of existing or predicted seismic events in the area.

The paper presents the results of research concerning the assessment of dynamic resistance of existing industrial hall structures located in areas with different seismic activity. The basis for analyses was a three-nave industrial hall with a steel structure. Numerical calculations were performed using the finite element method (FEM), using the response spectrum method in dynamic analysis. The calculations were carried out in variants, using standard accelerated response spectra according to Eurocode 8 and those determined for the Upper Silesian Coal Basin (USCB) and Legnica-Glogow Copper District (LGCD) area. Using the author's procedure for the assessment of the dynamic resistance, for each of the extortion analysed, the structure's response to the dynamic excitation was compared with the effects of load combinations adopted at the design stage, thus establishing the limit values of the design horizontal ground acceleration a max/g,h understood as the structure's resistance to tremors. This allowed to assess the impact of seismic activity from a specific area on the dynamic resistance of the subjected object. The article also discusses the way of interpretation and the scope of application of the obtained results and proposed procedure.