Civil and Environmental Engineering Commons^™

Multiple Reference Impact Testing Of Bridges Using A Network Of Low-Cost Dynamic Exciters, James David Lindsey

Graduate Theses and Dissertations

Multiple Reference Impact Testing (MRIT) is a form of Experimental Modal Analysis (EMA) that can be used to identify the dynamic properties of full-scale bridges. These dynamic properties include natural frequencies, mode shapes, damping ratios, modal scaling and modal flexibility. Since these system properties that are directly related to the mass and stiffness characteristics of a structure, impact test measurements can be used to quantitatively characterize condition of a structure. Over time, changes in the properties can be monitored and evaluated as indicators of damage or deterioration. Instrumented hammers and drop masses are typically used to perform MRIT by providing …

Uniform Temperature Predictions And Temperature Gradient Effects On I-Girder And Box Girder Concrete Bridges, Edyson Rojas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Federal Highway Administration (FHWA) created the Long-Term Bridge Performance (LTBP) program with the objective of acquiring quality scientific data for in-service bridge performance throughout the United States. This information will be used to improve the practices of bridge design and maintenance. To accomplish this objective, a variety of sensors were installed on a bridge south of Sacramento, California and a bridge near Perry, Utah. Data from the sensors is constantly gather and analyzed.

This research analyzed the data from the temperature sensors in order to investigate the effect of temperature changes in the California and Utah bridges over a …