Problems of Engineering Seismology: article

Аnnotation: To solve the problem anti-seismic strengthening, of building integer macroseismic intensity is not enough, because this intensity cannot describe the territory seismic hazard. For to this aim, it is necessary to set peak accelerations and to evaluate their statistical parameters. To this end, the paper describes constructing the probability density function of the peak acceleration for the building site. The basic data for such a construction is the shaking of the territory, the values of peak accelerations on the seismic scale, as well as the hypothesis on the distribution of peak accelerations according to Weibull's law, on conditions that the earthquake has occurred. The values of peak accelerations are taken in accordance with the new seismic scale developed by F.F. Aptikaev. The territory shaking was taken in accordance with the traditional linear dependence of the repeatability logarithm on the macroseismic intensity. The limitation by integer intensity values leads to a polyextremal distribution of peak accelerations with peaks at integer intensity values, since it is assumes that there are no earthquakes with intermediate intensities. A peculiarity of the research consists in constructing the probability density function of the peak accelerations without using the discrete value of macroseismic earthquake intensity, but using its continuous calculated value and replacing summation over the discrete intensity values with the corresponding integration. As a result, a monotonically decreasing distribution density function is obtained, which, at a first approximation, can be described as exponential distribution.