Nonlinear modeling of the ten-story RC building at E-Defense (2015): assessment with different modeling assumptions

Abstract

Two models of the 10-story reinforced concrete building tested at E-Defense laboratory in 2015 are built: the F model, in which nonlinear behavior is distributed over the element length, and the H model, in which nonlinear behavior is lumped in plastic hinges with a moment-chord rotation response assigned based on empirical formulations proposed in the literature. Nonlinear time–history analyses are performed to reproduce the experimental shaking-table tests performed at increasing seismic intensity level. The incremental experimental test has been performed twice: the first time (BS test), the structure base was free to slip on a concrete base fixed to the shaking table. After the BS test, a second test was performed on the same structure with the foundation fixed to the concrete base (BF test). Both tests are simulated for both models. When simulating both the BS and BF tests, the seismic input adopted for the numerical analyses is the displacement time-history registered at the base of the specimen’s columns, in order to implicitly account for base slip through the input signal without explicitly modeling the slipping devices. It is observed that the significant damage experienced by the specimen during the runs of BF tests at medium–high seismic intensity is probably triggered by softening and damage of beam-column joints: this is reproduced also by H numerical model and highlights the influence of beam-column joints on the overall seismic response of the structure. In general, it is observed that both numerical models, which were constructed, based on experimental data, only by adopting available and well-established tools proposed in the literature, can reproduce the overall response of the case-study structure, especially in terms of maximum top displacement demand and maximum damage state for structural members, provided that beam-column joints’ contribution is adequately considered.