Analysis of the Effective Seismic Support Damping in a Class I Piping System

Based in the existing literature, it is understood that the supports strongly influence the behaviour of piping during earthquake. Given that the level of seismic dissipation depends on the specific support system, the subject of effective damping provided by seismic supports has not been widely explored. This paper investigates this issue for the feeder pipes of a CANDU^® reactor. Feeders are numerous class I pipes in parallel, which are separated by frictional spacer elements. The piping system is analyzed using the time history method, taking into account the different damping mechanisms present. By comparing this and a response spectrum analysis of piping, the effective damping in the system is deduced. The effect of specific parameters on the results and the relationship between linear and nonlinear analyses are discussed.