Structural Health Monitoring Of Klehini River Bridge

This paper provides the reader with a methodology to evaluate the structural condition of a bridge in a remote area in eastern Alaska, in the United States. It was the objective of this work to develop a Structural Health Monitoring (SHM) program for the Alaska Department of Transportation (AKDOT) for the purpose of improving both bridge safety and asset management. The idea is to evaluate structural integrity, serviceability, and to gather information to help determine if the structure is undergoing change. This is done by monitoring structural response (strains, accelerations, mode shapes and natural frequency). A three-dimensional element finite element model of the bridge is recommended to track behavior with change. This model should be part of the SHM and used to evaluate the sensitivity of change. A modal analysis combined with results from field inspections are proposed for use in establishing a bridge SHM system. The system has a preferred sensor layout, system integrator and instrumentation suitable for Alaska’s remote locations and harsh weather conditions. A variety of sensors are proposed to measure and monitor structural and environmental conditions. These recommendations are provided to assist in evaluating safety and performance of the Klehini River Bridge. SHM will act as a safety and management tool. It is to complement traditional bridge inspection methods, provide overload warnings and help with asset management. Implementation of an SHM may reduce the inspection manpower, assist with early detection of deteriorated and damaged elements and provide the tools to obtain both an optimum inspection cycle and improved repair schedules.