Due to an aging infrastructure inside the United States and advances in technology, innovative structural health monitoring methods are emerging. Both short and long term health monitoring of structures can yield valuable data which can be used to determine the condition and capacity of the structure. Much research has been performed in the area of long term health monitoring (defined as monitoring where the instruments are left for days, months or years) but short term monitoring is an emerging field. This document focuses on short term monitoring utilizing an instrument that is new to North America as of 2009.;The subject instrument is the “IBIS-S” system which uses local interferometric radar to monitor structural movement wirelessly and in a non-contact manner. As this system is lightweight and wireless it is easy to quickly deploy, without interrupting the use of the structure, and allows the user to begin collecting data under live loads within hours. Outside of Europe, little research and verification of interferometric radar technology has been conducted on structures. This thesis presents interferometric radar theory, development and application as it relates to cable stayed bridges, particularly towards monitoring the health of the cables and overall natural frequencies of the bridge.;It will be shown that interferometric radar can successfully be used to monitor the tension force and health of the cables as well as the global frequencies of the bridge. A protocol for monitoring the cables and the overall natural frequency for the City and County of Denver’s cable stayed pedestrian bridge where 16th street crosses the Platte River is presented. Through the use of interferometric radar, baseline data was established for the subject bridge and it was determined that the fundamental frequency of the bridge is below the 3 Hz recommendation set forth in AASHTO standard.
展开▼
