Effect of inadequate lap splice length on the seismic fragility of bare RC frames

Abstract

Many researchers have investigated the seismic performance of low-ductile reinforced concrete (RC) frames during past decades. A literature review shows that the effects of inadequate lap splice length on the seismic vulnerability of RC frames have not been well addressed. However, it has been shown that columns with inadequate lap splice length exhibit significantly smaller rotational capacities. Therefore, this study investigated the effects of inadequate lap splice length on the seismic fragility of bare RC frames. For this purpose, 3, 6, and 9-story RC frames were designed, and their fragility curves were derived, assuming an inadequate lap splice length for their columns' reinforcement. In the derivation of fragility curves, 15 far-field natural earthquake records were used. Incremental dynamic analysis was employed to determine the drift capacities and demands. The obtained results indicated that shorter structures had larger inter-story drift capacities. Besides, frames with inadequate lap splice length exhibited a significantly larger probability of exceeding damage states than frames with adequate lap splice length.