Structural health monitoring of cable-stayed bridge using wireless smart sensors

Abstract

Wireless smart sensors (WSS) have great potential on the realization of effective structural health monitoring (SHM) of civil infrastructure. This study aims to develop and improve the state-of-the-art WSS technology for SHM of a large cable-stayed bridge in practice. This study has been carried out in conjunction with two international collaborative researches. One is for the development of an autonomous wireless tension estimation system between KAIST and University of Michigan (UM), and the other is for the construction of SHM test-bed on a cable-stayed bridge using large-scale wireless smart sensor network (WSSN) among KAIST, University of Illinois at Urbana-Champaign (UIUC), and University of Tokyo (UT). Decent WSS prototypes developed by UM (WiMMS) and UIUC (iMote2-based WSS) have been utilized in this study. An autonomous wireless tension monitoring system is developed using WiMMS by embedding autonomous vibration-based tension estimation algorithm, composed of Welch’s method, automated peak-picking algorithm, and recursive-form practical formula, for cable structures. The developed system has been validated on a series of laboratory tests using a scaled cable model. An SHM test-bed using large-scale wireless smart sensor network (WSSN) is constructed on a cable-stayed bridge in Korea to validate the developed WSS and SHM technologies on a real cable-stayed bridge. A total of 70 iMote2-based WSS nodes with 210 sensor channels have been successfully deployed on the cable-stayed bridge using two base stations with proper environmental hardening. Using the measured acceleration data from the test-bed bridge, modal properties of the whole structure composed of the deck and pylons and the tension forces of cables are obtained, and possible resonance of cables by cable-deck interaction is investigated. Hierarchical parameter clustering (HPC) technique based on the sensitivity similarity is proposed for the grouping of updating parameters to be used in the FE ...