Exceptional snowfalls and the assessment of accidental snow loads for structural design

Aiming at the assessment of accidental snow loads for the design of structures, a new approach to the analysis of exceptional snowfalls is suggested. The analysis incorporates both the attitudes of civil engineering and climatology on this natural phenomenon. Analysing the records of snow load annual maxima on the ground at measuring stations in Slovakia, the locations of occurrences of exceptional snow loads are identified. Then a climatological expertise is conducted resulting in the delimitation of three continuous lowland regions and a region of scattered mountain hollow-basins, in each of which similar climatological conditions for the occurrence of exceptional snowfalls can be expected. Within an individual region, an empirical probability distribution function based on annual snow load maxima at the observation stations is created, the upper tail of which is approximated by probability distribution functions of heavy and light tails. The accidental snow load on the ground corresponding to a mean return period of 10,000 years is assessed by the best fitting distribution function.