Inelastic Seismic Test of the Small Bore Piping and Support System: Part 1 — Seismic Proving Test of the Small Bore Piping System

Abstract

Seismic safety is one of the major key issues of nuclear power plant safety in Japan. It is demonstrated that nuclear piping possesses large safety margins in the various piping ultimate test reports. But it is appeared that there still remain some technical uncertainties about the phenomenon when both piping and supports show inelastic behavior in the extremely high seismic excitation level. In order to obtain the influence of the inelastic behavior of the support to the whole piping system response, and the subsequent interaction when both piping and supports show inelastic behavior, the following two tests have been started. • Support element test: Load-displacement characteristics of the support system including U-bolt, support itself and concrete anchorage are obtained by the forced displacement test. • Seismic proving test of piping system: The small bore piping and support system consisted of three dimensional piping, supports, U-bolts, and concrete anchorages will be excited on the table by the extremely higher seismic level. This paper introduces the major results of seismic proving test of piping and support system. The support element test results is presented in the paper of part 2, and the simulation analyses of these tests are summarized in the paper of part 3 [1, 2].

Investigation of the Seismic Safety Capacity of Aged Piping System: Shake Table Test on Piping Systems With Wall Thinning by E-Defense

“…In order to ensure the seismic safety of degraded piping systems under severe seismic events, it is important to clarify the effect of degradation on the dynamic behaviors, the failure modes and the ultimate strength of piping systems, and to estimate the seismic safety capacity of degraded piping systems based on the reliable experiments and numerical analyses. Though there are a lot of excitation tests and numerical analyses on piping system models without degradation or pipe elements with degradation [1][2][3][4][5][6][7][8][9], the studies on degraded piping systems are not numerous, and the data to discuss the safety capacity of degraded piping systems are still insufficient. The authors have conducted a series of experiments and analyses to investigate the ultimate strength and the failure modes of pipe elements and piping systems with or without degradation, and established the analytical model to estimate the fatigue life of piping systems [10][11][12][13].…”