Health monitoring of UCSD's I-5/Gilman advanced technology bridge

Abstract

The main features of the advanced composite bridge that the University of California, San Diego is planning to build over interstate I-5 in California are presented. This bridge will utilise a number of fibre-reinforced-polymer components as structural members. The aim of the project is to demonstrate the use of these advanced materials in civil infrastructures. The main focus of this article is the health monitoring plan for the bridge. A number of advanced NDE and conventional methodologies will be used to monitor the bridge behaviour during its service life. The methods and sensors employed will include infrared thermography, ultrasonic testing, electrical resistance and fibre-optic strain gauges, accelerometers and acoustic emission testing. The results of an acoustic emission test for failure monitoring of a carbon-reinforced-polymer cable for potential use in the bridge are presented. The test allowed detection of early failure at 52%, 65%, 82% and 87% of the cable's ultimate load. This damage could not be detected by the traditional observation of stiffness changes. The results are used to compare different sets of cables currently under test, with the purpose of finalising the design of the bridge. An array of acoustic emission sensors will be employed in service for early warning of possible failure of the structure.