This thesis presents an investigation into the structural behavior of a concrete beam with welded connections in an operational parking garage. Long-gauge fiber Bragg grating (FBG) sensors were installed at strategic locations to measure strain under various loading configurations. The research explores the discrepancies between numerical calculations and measured beam response to understand how the complex geometry and boundary conditions influence structural behavior. Finite element analysis (FEA) simulations were conducted using Abaqus software to establish boundary conditions representing two extreme cases: a simply supported beam and a beam with constrained points. These models served as limit states for interpreting the influence of welded connections on beam strain. Measured strain data was compared with FEA predictions, and the effect of welded connections was quantified using a percent effectiveness metric. Results demonstrate that welded connections exert diverse influences on beam deflection depending on both measurement location and load configuration. The connections' behavior generally falls between that of a simply supported beam and one with fixed constraint points, with the proximity to either extreme end condition varying throughout the beam. FEA models showed particular difficulty in accurately predicting lateral bending behavior. The study was constrained by limitations in sensor placement, load magnitude restrictions, and simplifications in the FEA models. Despite these constraints, the methodology demonstrates an effective approach for analyzing structures with complex geometries and boundary conditions. This research contributes to understanding CarbonCure concrete performance in operational structures and supports the ongoing development of structural health monitoring techniques that can enhance the safety and maintenance of built infrastructure.

Rocking isolation is a form of base isolation that relies on a structure’s ability to uplift and rock during ground excitations, dissipating energy via impact with the ground. In 2D, the planar rocking motion is easily understood and modeled. But in the 3D scheme, the system becomes more complex, requiring more intensive calculations and parameters to consider. This thesis will use Distinct Element Modeling to simulate the 3D rocking behavior of free-standing columns and their framed systems. A parametric approach is taken to examine how a column’s geometry and a frame’s orientation can impact its rocking behavior and overall stability under various ground accelerations modeled using a Single-Pulse Sine wave and time history velocities of recorded earthquakes. The analyses reveal that a column’s capacity to endure intense ground excitations can be predicted based on its column’s size and shape. Additionally, this thesis finds that when an array (2D) or matrix (3D) of solitary columns are capped by a freely supported, rigid beam or slab, its capacity to endure intense ground movements is enhanced. The rocking behavior will be ascertained through the numerical analysis of the vertical displacements and velocities of the column’s centroid, in tandem to the qualitative observations of the system’s overall displacements from its original position. Small-scale, physical experimentations are performed to provide qualitative observations of how the 3D rocking model behaves under real-time loading conditions and constraints. Discussion of results will be done in context of performance-based design criteria in hopes of informing applications to modern designs.