ABSTRACT
Vibration-based condition assessment methods have been studied widely and developed for the last 25 years as a structural health monitoring (SHM) tool for bridges (Owen et al., 2004). Even with the presence of their experimental errors, measurements from these methods give a more reliable representation for a tested structure than the simulated analytical model (Hwang & Kim, 2004). Stiffness coefficients of a structure could be directly determined by EMA without any need for analytical support, when the test and processing of data are planned and implemented well. No other testing method could provide such comprehensive information for actual structures (Zhengsheng et al., 2005). Although the methods of utilising vibration data seem straightforward, in principle, their effective application has proved remarkably challenging, because vibration tests are generally complemented by many issues related to creating accurate and repeatable measurements (Owen & Pearson, 2004). In addition, the extracted vibration data are difficult to interpret and relate to the location and size of damage. To that end, the usage of modal parameters to identify the amount of damage for concrete structures is still a subjective, and not necessarily, robust process (Wang et al., 2007; Kim & Stubbs, 2003).
