Free-field vibrations can be induced not only by earthquakes, but also by so-called paraseismic sources, for instance, mining tremors. Mining-induced seismicity has been recorded in many countries in mining areas with the underground exploitation. The mining rockbursts are a hazard to surface structures since ground motion can result in their damage. Legnica-Glogow Copperfield (LGC) is the most seismically active mining region in Poland. Records of mining-induced vibrations simultaneously registered on the free-field close to a building, and at the foundation level of the building, can differ significantly in this area. This occurs as a result of soil-structure interaction, which is visible in the transmission of ground vibrations to building foundations. Therefore, the responses of buildings determined on the basis of recorded free-field vibrations may be different from the responses obtained with an application of building foundation vibrations. Convenient in practice, simple, approximate way to assess the harmfulness of mine-induced vibrations to buildings, is the use of appropriately prepared scales. They are based on the parameters of ground vibrations. This paper deals with the evaluation of harmfulness of mine-induced vibrations in LGC region to an actual medium-rise apartment building. The Mining Intensity Scale GSI-2004/11 and SWD-II scale have been applied. Estimation of the intensity of surface vibrations according to these scales has been performed using recorded free-field and, for research purposes, also foundation vibrations. The influence of the place of surface vibrations measurements on the evaluated intensity of vibrations has been analysed. It was stated that significant differences can occur in the classification of the same mining tremor depending on whether the evaluation had been performed on the basis of the free-field vibrations or on the building foundation vibrations measured on the same time. (C) 2017 The Authors. Published by Elsevier Ltd.
