Performance-Based Seismic Monitoring of Instrumented Buildings

This dissertation develops a new concept for performance-based monitoring (PBM) of instrumented buildings subjected to earthquakes. This concept is achieved by simultaneously combining and advancing existing knowledge from structural mechanics, signal processing, and performance-based earthquake engineering paradigms. The PBM concept consists of 1) optimal sensor placement, 2) dynamic response reconstruction, 3) damage estimation, and 4) loss analysis. Within the proposed concept, the main theoretical contribution is the derivation of a nonlinear model-based observer (NMBO) for state estimation in nonlinear structural systems. The NMBO employs an efficient iterative algorithm to combine a nonlinear model and limited noise-contaminated response measurements to estimate the complete nonlinear dynamic response of the structural system of interest, in the particular case of this research, a building subject to an earthquake. The main advantage of the proposed observer over existing nonlinear recursive state estimators is that it is specifically designed to be physically realizable as a nonlinear structural model. This results in many desirable properties, such as improved stability and efficiency. Additionally, a practical methodology is presented to implement the proposed PBM concept in the case of instrumented steel, wood-frame, and reinforced concrete buildings as the three main types of structural systems used for construction in the United States. The proposed methodology is validated using three case studies of experimental and real-world large-scale instrumented buildings. The first case study is an extensively instrumented six-story wood frame building tested in a series of full-scale seismic tests in the final phase of the NEESWood project at the E-Defense facility in Japan. The second case study is a 6-story steel moment resisting frame building located in Burbank, CA, and uses the recorded acceleration data from the 1991 Sierra Madre and 1994 Northridge earthquakes. The third case is a seven-story reinforced concrete structure in Van Nuys, CA, which was severely damaged during the 1994 Northridge earthquake. The results presented in this dissertation constitute the most accurate and the highest resolution seismic response and damage measure estimates obtained for instrumented buildings. The proposed PBM concept will help structural engineers make more informed and swift decisions regarding post-earthquake assessment of critical instrumented building structures, thus improving earthquake resiliency of seismic-prone communities. Citations Material from this dissertation has been published in the following form: • Roohi, M. , Hernandez, E. , Rosowsky, D. (2019). “Nonlinear Seismic Response Reconstruction and Performance Assessment in Minimally Instrumented Woodframe Buildings Validation using NEESWood Capstone Full-Scale Tests”. Journal of Structural Control and Health Monitoring, p.e2373. • Roohi, M. , Hernandez, E. , Rosowsky, D. (2019). “Nonlinear Seismic Response Reconstruction and Performance Assessment of Instrumented Woodframe Buildings Validation using NEESWood Capstone Full-Scale Tests”. Proceedings of theEngineering Mechanics Institute Conference (ASCE-EMI), California Institute of Technology (CalTech), Pasadena, California, USA. • Roohi, M. , Hernandez, E. , Rosowsky, D. (2019). “Nonlinear Seismic Response Reconstruction in Minimally Instrumented Buildings Validation using NEESWood Capstone Full-Scale Tests”. Proceedings of the 12th International Workshop on Structural Health Monitoring (IWSHM), Stanford University, California, USA. • Roohi, M. , Hernandez, E. , Rosowsky, D. (2019). “Seismic Damage Assessment of Instrumented Wood-frame Buildings: A Case-study of NEESWood Full-scale Shake Table Tests”. arXiv preprint arXiv:1902.09955. • Hernandez, E. , Roohi, M. , Rosowsky, D. (2018). “Estimation of elementby-element demand-to-capacity ratios in instrumented SMRF buildings using measured seismic response”. Journal of Earthquake Engineering & Structural Dynamics, 47(12), 2561-2578. • Roohi, M. , Hernandez, E. , Rosowsky, D. (2017). “Element-by-Element Demandto-Capacity Ratio Estimation from SMRF Building Seismic Records”. Proceedings of the 7th International Conference on Experimental Vibration Analysis for Civil Engineering Structures (EVACES), University of California San Diego (UCSD), California, USA. And Material from this dissertation has been submitted for publication to the ASCE Journal of Engineering Mechanics on May 1, 2019 in the following form: