The project involves physical testing of three existing buildings that are scheduled for demolition on the campus of The Ohio State University in Columbus to study the progressive collapse characteristics of building structures. To study the building collapse vulnerabilities as recommended by the current design guidelines, the structural columns in the first stories will be removed and response of the buildings will be monitored. This study will provide much needed experimental data on full-scale buildings to validate the results of computational studies reported in the literature and to verify the methodologies prescribed in the design guidelines. The project will improve understanding of progressive collapse process by addressing: 1) redistribution of loads within the building following loss of columns, 2) contribution of slabs and transverse and longitudinal beams in bridging over the failed column, and 3) structural system characteristics that determine how a structural collapse mechanism forms. The experimental data will be used to validate and refine advanced nonlinear analysis tools and to develop simplified models and analysis procedures that can be used by practicing engineers. The results of this research will enable more accurate assessment of collapse potential of buildings and, as a result, will lead to more efficient design of new buildings and retrofit of existing buildings. Simulation data will be used to evaluate the amplification factors recommended by the design guidelines for linear static analysis.
This research is expected to provide scarce full-scale experimental data of immense value to advance engineering understanding about progressive collapse of buildings. The project will involve graduate, undergraduate students from underrepresented groups in science and technology education. Hands-on demonstrations will be given and competitions will be conducted at high school level.
The primary objective of the project was to investigate progressive collapse response of frame buildings thorough experimental testing and numerical simulations. The experimental research included testing of four existing frame buildings by physically removing first-story columns and monitoring the structural response during and after column loss. Before the testing of one steel and three reinforced concrete buildings, columns and beams neighboring the target column were instrumented with strain gauges and displacement sensors to monitor redistribution of loads using a portable data acquisition system. In one test building the column was removed using a 2-ton wrecking ball. The columns in the other three buildings were cut with the help of crushing/pinching demolition equipment in a short period of time. The computational phase of the project involved development of detailed and simplified building models and corresponding analyses to assess progressive collapse potential of the test buildings. Test buildings were modeled using the structural analysis software SAP2000. The main response parameters included demand-to-capacity ratios (DCRs), and member strains and displacements calculated from nonlinear dynamic analysis. Static and dynamic building simulation results were compared with the measured test data. The experimental and computational research data enhanced understanding of progressive collapse mechanism of frame buildings.
