The paper presents analysis of the vibrational environment on scaffoldings. It is based on the results obtained in the project considering workers safety on scaffoldings. The total number of 120 façade scaffoldings was analysed over a period of two years. One of the issues considered in this project was the vibrations influence on scaffoldings and workers safety. The values of natural frequencies were obtained based on in-situ measurements of free vibrations. Analysis of the tests results made it possible to verify the elaborated numerical models. Values of natural frequencies and displacements in mode shaped from numerical modal analyses were compared with test results. Measurements of forced vibrations were also made with various sources of vibrations active at scaffoldings. The detailed numerical dynamic analysis was performed considering excitation forces variable in time. The obtained results were compared with allowable values according to the appropriate Polish standards. Most influential sources of vibrations for human comfort were indicated in the conclusions.

Eurocode standard recommends using fundamental basic wind velocity (characteristic velocity) as the design value in civil engineering. There are different approaches to estimate this value depending on the climate features of the given area and the quality of environmental data. The estimation of the characteristic value requires statistical analysis of historical data regarding wind velocities measured throughout the country at meteorological stations. The results of the analysis are probability density distributions of this random variable for each meteorological station. On this basis, values of characteristic wind velocity with a mean return period of 50 years are determined. The zones with uniform velocities are delineated on the map of the country. In the case of Poland the last evaluation of wind zones took place over 15 years ago. Higher quality of measurement data on the one hand, and the introduction of the second generation of Eurocode standards on the other hand, create a need to check and update these zones. This work presents theoretical basis for the estimation of characteristic values of random variables in the context of wind velocity, comprehensively reviews practical methods used for this purpose and summarizes current situation in Poland, finally discusses the issues related to the heterogeneity of wind data, illustrating them with an example.