Highlights

From the rupture to the buildings: reconciling engineering evidences of the April 6 2009 L’Aquila earthquake (Mw 6.3).

AGU Fall Meeting, San Francisco, USA, 14-18 December, 2009
V. Convertito et. al

Abstract

The April 6 2009 L’Aquila earthquake (Mw 6.3) was the first case, in Italy, of a well recorded seismic event the near-source region of which is densely populated of engineering structures. In fact, because of the short distance from the fault (0km Joyner and Boore distance), the strong motion parameters relevant for the damage description may not be obtained by 1D attenuation relationships, which do not account for fault extension and fail in the fault vicinity. On the other hand, the large amount of data coming from strong-motion, regional and teleseismic records, GPS, SAR, surface geology, geotechnical profiles and detailed damage surveys provide an unique opportunity to investigate the effects of the rupture and propagation on the seismic response of buildings. Because in Italy the current state of earthquake engineering research and its interaction with bordering Earth Sciences may be considered advanced, also because it recently benefitted of large research programs funded by the governmental department for civil protection, a research group (AQ-FII) has been set up to apply an integrated approach to reconcile earthquake engineering evidences from the event. State-of-the art models are employed to simulate source, path, site effects and engineering systems’ response. This ambitious project has a threefold scope: (1) to confirm and/or explore seismologic near-fault effects and their modelling issues; (2) to deepen structural and geotechnical engineering understanding of near-source seismic response and observed variability at small scale (i.e., individual structure level); (3) to validate the comprehensive and multi-disciplinary approach to earthquake science invoked in the last decades. The AQ-FII group includes: a seismological component for the modelling of the source and radiation; a geological component characterizing the propagation features at large scale in the region (the Aterno valley); a geotechnical competency for the characterization of selected site effects; and a structural engineering component for the simulation of nonlinear seismic response and damage for a selected suite of reinforced concrete buildings. Calibration of all steps is empirical and requires field investigations. As a side task, an attempt is also made to reconcile macroseismic intensity data observed in the area with the expected damage from simulated ground shaking. In this study the work breakdown structure, actual and wish-list input data, critical issues, ongoing work and preliminary results are presented and discussed.