Experiments on Seismic Performance of Piping Mounted to a Concrete Floor by Post-Installed Anchors

Abstract

In nuclear power plants, non-structural systems such as piping are often connected to concrete floors by post-installed anchors. During an earthquake, the anchors have to transfer the dynamic loads between the structural and mechanical components of the power plant. The dynamic behavior of the coupled system concrete-anchor-piping is not only governed by the main components but also by the load-bearing behavior of the anchors and the dynamic behavior of pipe supports. Stiffness reduction of supports can lead to contact problems. Impact loads due to gaps between the anchor plate and concrete floor occur when the anchors show significant displacements. Uncertainties concerning possible interactions of the coupled system concrete-anchor-piping can lead to unexpected failure modes during the system response. To investigate these possible interactions, experiments and detailed numerical simulations regarding the dynamic behavior of the coupled system concrete-anchor-piping are carried out. Results of experiments and numerical simulations on the seismic performance of a mock-up consisting of piping, anchors and a structural concrete member subjected to crack cycling are presented.