Shake Table Tests on Suspended Nonstructural Components Anchored in Cyclically Cracked Concrete

Abstract

Insufficient anchorage of nonstructural components is a substantial cause of earthquake damage. To investigate this issue, shake table tests were conducted on model nonstructural components suspended and supported via anchors cast in cyclically cracked concrete. Concrete slabs supporting the anchored model component were subjected to seismic floor accelerations and corresponding floor-level cyclic crack width histories to simulate the anchor boundary conditions found in concrete structures during an earthquake. For these tests, post-installed anchors, namely, undercut and expansion types, were tested at various seismic demand levels. This paper presents this unique test data and illustrates important seismic anchor performance characteristics. For the investigated case, the measured correlation between anchor load and crack width indicated a low average anchor load level. In addition, the cumulative anchor displacements and achieved ultimate load capacities showed conservatism when compared with results of simulated seismic tests on isolated anchors.