STUDIES ON THE STATISTICAL ASEISMIC SAFETY OF RELATIVELY LONG PERIOD STRUCTURES

Abstract

The authors tried to study the aseimic safety, in a statistical sense, of relatively long period structures through dynamic analysis. The earthquake characteristics, the properties of structural dynamics and those of the foundation layer are the essential contributing factors to structural behaviours; therefore, they are included as parameters in the safety criterion deduced.
The statistical description of strong earthquakes is executed both for their random sequences of occurrence and for their individual random ground motions. Through the latter simulation, the nonstationary vibration of structures is investigated. The probability of failure by application of a finite duration of motion is obtained from the first-passage problem. By introduction of this quantity into the former assumed distribution function, the risk of failure of structures associated in their service period is evaluated.
The results are presented in an available spectrum form as the information on the aseismic integrity of a structural product.