A full-scale seven-story reinforced concrete building section was tested on the UCSD-NEES shake table during the period October 2005 -January 2006. The shake table tests were designed to damage the building progressively through four historical earthquake records. At various levels of damage, ambient vibration tests and low amplitude white noise base excitations with root-mean-square accelerations of 0.03g and 0.05g were applied to the building, which responded as a quasi-linear system with parameters evolving as a function of structural damage.Modal parameters (natural frequencies, damping ratios and mode shapes) of the building were identified at different damage levels based on the response of the building to ambient as well as low amplitude white noise base excitations, measured using DC coupled accelerometers. This paper focuses on damage identification of this building based on changes in identified modal parameters. A sensitivity-based finite element model updating strategy is used to detect, localize and quantify damage at each damage state considered. Three sets of damage identification results 1. Corresponding author. Tel.: +1 858-822-4545; fax: +1 858-822-2260. E-mail address: jpconte@ucsd.edu 2 are obtained using modal parameters identified based on ambient, 0.03g, and 0.05g RMS white noise test data, respectively. The damage identification results obtained in all three cases do not exactly coincide, but they are consistent with the concentration of structural damage observed at the bottom two stories of the building. The difference in the identified damage results is mainly due to the significant difference in the identified modal parameters used in the three cases. The assumption of a quasi-linear dynamic system is progressively violated with increasing level of excitation. Therefore, application of nonlinear FE model updating strategies is recommended in future studies to resolve the errors caused by structural response nonlinearity.

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SUMMARYFloor horizontal accelerations are needed for obtaining forces for the design of diaphragms, for the design of their connections and for the design of non-structural components and equipment supported by structures. Large oor horizontal accelerations have been recorded in buildings during earthquakes. Such accelerations have been responsible for inertia forces causing damage to services and are a major reason for structural damage and even building collapse.This paper describes an analytical investigation into earthquake-induced oor horizontal accelerations that arise in regular buildings built with rigid diaphragms. The paper also describes several methods prescribed by design standards and proposes a new method. The method is based on modal superposition modiÿed to account for the inelastic response of the building's lateral force resisting system. Results obtained from time-history inelastic analysis are compared with the proposed method.

Precast concrete facilitates a construction method using durable and rapidly erectable prefabricated members to create costeffective and high-quality structures. In this method, the connections between the precast members as well as between the members and the foundation require special attention to ensure good seismic performance. Extensive research conducted since the 1980s has led to new precast concrete structural systems, designs, details, and techniques that are particularly suited for use in regions of high seismic hazard. This paper reviews the state of the art of these advances, including code developments and practical applications, related to four different systems: (1) moment frames; (2) structural walls; (3) floor diaphragms; and (4) bridges. It is concluded from this review that the widespread use of precast concrete in seismic regions is feasible today and that the jointed connection innovation introduced through precast research leads to improved seismic performance of building and bridge structures.dividual papers. This paper is part of the Journal of Structural Engineering, © ASCE, ISSN 0733-9445. © ASCE 03118001-1 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-2 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-3 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-4 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-5 J. Struct. Eng. © ASCE 03118001-10 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-11 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-18 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18.