Practical issues in using novel sensors in SHM of civil infrastructure: problems and solutions in implementation of GPS and fibre optic sensors

Abstract

Two contemporary research programs have explored the use of newer type of sensors believed, and advertised, to have potential in future implementation of SHM system for civil structures. Fibre optic sensors have the possibility to record a range of physical parameters simultaneously and at high speed through multiplexing capabilities of the fibre Bragg grating (FBG); GPS has the advantage to measure absolute displacement of slowly moving flexible structures without need for optical line of sight. FBG sensors have been tested in laboratory situations and have finally been implemented for strain measurements in an expressway viaduct construction program. Meanwhile, a twin-rover GPS system mounted on top of one of Singapore’s tallest buildings has recently provided real-time static and dynamic response data as part of an existing monitoring system designed to study structural performance during wind and earthquake loading. Some of the first results of these two programs will be presented. Both implementations have been problematic in different ways and the paper will identify some of the difficulties and the solutions adopted. The practical limitations and optimal applications can thus be identified.