Effects of Long Distance Earthquakes on Tall Buildings: Seismic Risk in Buenos Aires

SEBASTIÁN VAQUERO; JUAN MUSSAT; RAUL BERTERO

Santiago

Congreso; 16 World Conference on Earthquake Engineering; 2017

Chilean Association of Seismology and Earthquake Engineering

The Chilean 8.3 Magnitude Earthquake of September 16 2015 produced panic of inhabitants of tall buildings in Buenos Aires, 1300 km away. The main event and its aftershocks were registered by a new seismometer of Universidad de Buenos Aires. Using these data, the response spectra, the frequency contents and significant duration of the ground motions and the Inter Story Drift index and RMS acceleration on Buenos Aires tall buildings were computed. Damping and period of these tall buildings had been measured during a previous study. The results show that similar spectra are obtained for the main shock and the aftershocks showing that soil period is one of the main parameters to explain the large amplification of pseudo acceleration computed for the tall buildings. This soil period in Buenos Aires was computed showing similar values that the measured tall buildings natural period. The frequency content of ground motion on rock, 300 m below the surface, is obtained from deconvolution of the acceleration measured on surface. Finally, from the Chilean seismicity and the new attenuation law obtained for distant earthquakes, the return period of human discomfort and non-structural damage is obtained for current practice in Buenos Aires tall buildings.