Damage detection of a RC building subjected to base motion: data-driven methods

In this paper are presented the results of an experimental study concerning the damage assessment of a real building. The considered structure is the building of the Civil and Environmental Engineering Department at NCHU in Taichung which was subjected, between July 1998 and November 1999, to the Chi-Chi Earthquake main shock and numerous foreshocks and aftershocks. The building is instrumented by a monitoring system composed of 29 accelerometers. In the first section is introduced the case study and are presented the results deriving from the dynamic identification, performed by the authors in a previous work. Then, it is discussed the application of two approaches to the process of the vibration-based damage detection: the first one is a nonlinear approach which is based only on one record of the input and output signals, while the second one is a statistical analysis procedure, which sets the damage detection process in the context of a statistical pattern recognition paradigm and requires the use of two recorded output sets, in the undamaged and damaged states, respectively. All the proposed indexes are data-driven; consequently, they do not require any assumptions about the structural model and account for structural nonlinearities. The main goal of this investigation is to experimentally quantify the sensitivity of the examined damage indexes to the presence of structural damage and to test their efficacy in a real case.