Collaborative Research: Effect of Vertical Accelerations on the Seismic Performance of Steel Building Components: An Experimental and Numerical Study

University Of California-Irvine, Irvine CA

Investigators

Abstract

This award supports research to evaluate the effect of vertical accelerations on steel buildings during earthquakes using experiments and numerical models. Experimental studies on the impact of vertical accelerations on building response rarely have been conducted. Thus, numerical models cannot account for realistic data to predict the performance of building components. In this study, a near full-scale ten-story steel building will be instrumented to measure its vertical accelerations when tested on a shake table. The experimental data will be used to create numerical models to understand the behavior of beams, columns, slabs, and other components under vertical and horizontal seismic ground motions. The numerical models will be modified according to American design specifications to predict the seismic performance of steel buildings designed according to these standards and guidelines. Therefore, this research will improve the performance of steel buildings in seismic regions of the United States and provide much needed data for investigations on the vibration effects of beams and slabs on building occupants. The project will also support two Ph.D. students in the earthquake engineering field. The research outcomes will be disseminated through reports and journal publications. This project will contribute to the National Science Foundation (NSF) role in the National Earthquake Hazards Reduction Program. Data from this project will be archived in the NSF-supported Natural Hazards Engineering Research Infrastructure Data Depot (https://www.DesignSafe-ci.org). This study is a collaboration with the Japanese National Research Institute for Earth Science and Disaster Resilience (NIED) research team that will test the ten-story steel building on the 3D Full-Scale Earthquake Testing Facility (E-Defense) six-degrees-of-freedom shake table operated by NIED and located in Miki, Japan. The steel building includes moment resisting frames in the transverse direction and a dual system in the longitudinal direction consisting of interior buckling-restrained braced frames and exterior moment resisting frames. Non-structural components will be installed on several floors, as well as curtain walls. The structure will be subjected to ground motions with monotonically increasing seismic intensity, and structural components are expected to exhibit nonlinear inelastic behavior in the final stages of the experiment. The study tasks consist of i) implementing an instrumentation network in the ten-story steel building to collect accelerations and deformations on structural components during three-dimensional seismic shaking, ii) creating subassembly and system finite element models using research and commercial software platforms, resulting in validated modeling techniques to capture the impact of three-dimensional excitations, and iii) assessing the implications of vertical seismic demands on the structural resiliency of steel buildings designed according to U.S. practice. The study will produce the most complete and realistic modeling knowledge to date on the effect of vertical accelerations on steel buildings. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.