GPS BASED HEALTH MONITORING OF A CABLE STAYED FOOTBRIDGE

Abstract

I Icaith monitoring of a structure is the process or technique of acquiring and analyzing data of the structure to identify and study the damage in that structure. This is done for the assessment of as-built performance of the structure against the design criteria, to suggest for any structural changes in the design and to identify damages in a built structure, to suggest fr the urgency in the repair work of the structure. Over a long period, monitoring can also provide the opportunity to identify 'anomalies' that may signal unusual loading conditions or modified structural behaviour, which can, in the extreme case, include damage or failure. It can done using global and local techniques. Global technique includes evaluating the health of the complete structure and local technique means evaluating the health, of individual components of the structure. The various stages of health monitoring are determining that I damage is present in the structure, determination of the geometric location of damage, quantification of the severity of damage and lastly, predicting the remaining service life of the structure. The objective of this dissertation is to monitor the health of a cable-stayed foot bridge, opposite Irrigation Research Institute, Roorkee - Uttarakhand (India) using Global Positioning System (GPS) with the use of single frequency receivers. It is India's first cable stayed footbridge. As it is an essential utility structure, so it needs a regular health assessment. The technique followed for measurement of health is by detecting the change in the frequency of the footbridge. Also, acceleration, velocity and displacement are deduced From GPS observables in order to further use them in equation of motion to determine the mass, dampness and stiffness coefficients of the structure.