AbstractsEngineering

The series of recent extreme weather events and subsequent damage to the infrastructure has led to an increased concern regarding the design of structural systems for multi-hazard criteria. Since much of the multi-storied infrastructure of the twentieth century exceeds nearly fifty years of service, innovative instrumentation of buildings has attracted a great deal of research attention. These increased environmental concerns coupled with the increasing population density result in the operational demand on these structures far exceeding their original design criteria or capacity. This research addresses the response characterization of tall building structures subject to strong ground motion and wind loading. The time history of various building designs is developed using a finite element idealization of the building subject to various environmental loading scenarios. The resulting time series of the response behavior is obtained at each building floor elevation. The characterization of response behavior is analyzed using the Time Domain Decomposition (TDD) method, which requires no prior assumptions about the nature of time series or the excitation. TDD?s application is first studied on a 20-story building where the first three translational and rotational modes are examined. The analysis is then extended to a more flexible 52-story idealized version of a prototype of the Prudential Tower located in Boston, Massachusetts. This research study investigates the reconstruction of response time series for arrays of sensors located at various floor elevations recognizing that sensor failure may occur and that some information may be lost. The sensor configurations presented are used to illustrate some of the intricacies involved in the application of the TDD method that affect the accuracy of the reconstruction of time domain response behavior. The interpretation of data based upon modal filtering was demonstrated to influence the process of signal reconstruction, complicating the relationship between the number of sensors and the modal information. Further, it was observed that the response behavior due to wind loading, which is basically a unidirectional load varying with both elevation and time, when compared with that from the bidirectional seismic loading case is quite different although they excite similar modal frequencies. The insights gained from this study help to quantify the role of sensor placement on tall buildings that are subject to regional multi-hazard loading that will vary in terms of both the nature and intensity of dynamic excitation. The research study also identified deficiencies in the underlying methodology that need further investigation to improve the robustness of this approach as a tool for dynamic response characterization. Advisors/Committee Members: Niedzwecki, John M (advisor), Barroso, Luciana R (committee member), Newton, Joseph (committee member).