Reliability Design of the Piping System against Earthquake Excitation

This paper deals with the problem of the design of the piping system. Especially when the statistical properties of uncertainties of the system and those of an earthquake (i.e., its period, magnitude and statistical characteristics of the wave) are known, the statistical properties of the piping vibration can be obtained by using the hierarchy method, which is first applied to the reliability problem by one of the authors. Next a period of the first-passage failure of the piping system is calculated in a statistical sense. It is concluded that the statistical property of the seismic wave has more influence on the reliability than does the damping coefficient or other factors in the piping system.