Keywords: structural engineering, near–field areas, near–field seismic motions, moment resisting frames, passive protection, frame protection, probabilistic assessment, seismic protection, earthquakes, reinforced concrete, nonlinear analysis, six–story frames, hysteresis, energy dissipaters, base isolators, ground motion, frame buildings, building damage
Response of frames seismically protected with passive systems in near–field areas
The present paper analyses the behaviour of moment resisting frames in reinforced concrete subject to earthquakes recorded in near–field areas. In these areas, the signals show impulsive–type accelerograms, with velocity and displacement peaks higher than in far–field zones especially for the fault–normal component of the ground motion velocity in the direction of propagation of the wave, which shows large–amplitude pulses. In the following, seven near–field signals scaled in agreement with the design spectrum of the Italian code (NTC, 2008) have been adopted to perform a nonlinear analysis on a six–story frame. The response has also been determined for the same frame protected once with hysteretic–type energy dissipaters and once with base isolators. The aim of the present study is to acquire quantitative knowledge on the near–field ground motion effects on frame buildings and on their damage also in the presence of passive seismic protection systems.