RELIABILITY ANALYSIS OF EMBEDDED BASE CONNECTIONS

Column base connections are critical components of Steel Moment Frames (SMFs) since these connections transfer the loads (e.g., gravity, seismic) from the superstructure to the concrete foundation, being an interface between them. Because of it, these connections have been extensively investigated in the last decade. Notable large-scale experimental programs have been conducted, and numerical and analytical investigations have complemented these programs. Traditionally, column-base connections are divided into exposed base plates and embedded bases. The former type of connection is mainly used for low and mid-rise buildings, while the latter detail is the norm for tall buildings. The behavior of embedded base connections has been studied in recent experimental programs. As a result, design methodologies and models to simulate their hysteretic characteristics have been proposed. However, surprisingly a reliability analysis of these connections has not been conducted so far. Motivated by this issue, this study presents a reliability analysis of the embedded base connections with the aim of providing design recommendations. For this purpose, nonlinear mathematical models of archetype frames are developed and subjected to nonlinear dynamic analysis to obtain the column base connection demands. These results are then used to conduct statistical simulations and recommend preliminary resistance factors for the design of embedded base connections. Limitations of the investigation are discussed, and future lines of investigation are outlined.