Brett Story, Leven Deputy, Jase Sitton


The progressive collapse failure mode occurs in buildings when a load-carrying element is lost due to extreme events such as explosions caused by terrorist attacks or vehicular impacts. Guidelines and many researches efforts have been established in order to limit and prevent total collapse of buildings after losing a load-carrying component (e.g., a column). Two famous examples of progressive collapse are the 1968 Ronan Point apartment building kitchen explosion on the 18th floor and the 1995 Alfred P. Murrah Federal Building bombing in Oklahoma City. Both examples resulted in fatalities and injuries. A small number of these injuries and fatalities were due to the actual explosion while a larger number of lives were claimed during the subsequent progressive collapse event.

Progressive collapse guidelines have been developed to enhance the robustness of buildings against progressive collapse. Two of the main progressive collapse guidelines are the General Services Administration, “Progressive Collapse Analysis and Design Guidelines,” (GSA) and the Department of Defense (DoD) Unified Facilities Criteria 4-023-03 “Design of Building to Resist Progressive Collapse” (UFC 4-023-03) guidelines. In addition to these guidelines, many research efforts have been performed to investigate the ability of buildings to resist progressive collapse, such as development of a beam sub-model that has springs to simulate connection’s elements behavior, experimentation to facilitate the load-deflection relationship and connection behavior.

One of the most important findings in progressive collapse research is the effect of the load-deflection relationship at the connection where the column removal scenario occurs. This research focuses on the development of a beam sub-model that has longitudinal and rotational springs to simulate the surrounding frames and connection behavior. The sub-model equations approximate the vertical displacement of the connection subjected to the column removal and include nonlinear geometry (NLG) effects and some nonlinear material (NLMG) behavior. The derived equation is examined by simulating the behavior of both moment frame and braced frame. Additionally, the derived equations are used to simulate three different beam boundary condition scenarios: simply supported (PFP), Fixed-Fixed-Fixed (FFF), and modified catenary Pin-Pin-Pin (PPP); the results from these simulations are validated against existing experimental results. For the cases considered in this thesis, the RBSA model matches the finite element with in a range of 0% to 10%. Finally, the axial force contribution in the linear region is investigated.

Degree Date

Summer 8-4-2021

Document Type


Degree Name



Civil and Environmental Engineering


Dr Brett Story

Subject Area

Civil Engineering

Number of Pages




Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License