%0 Journal Article
%T Structural Health Monitoring of Precast Concrete Box Girders Using Selected Vibration-Based Damage Detection Methods
%A Zhengjie Zhou
%A Leon D. Wegner
%A Bruce F. Sparling
%J Advances in Civil Engineering
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/280685
%X Precast, prestressed concrete box girders are commonly used as superstructure components for short and medium span bridges. Their configuration and typical side-by-side placement make large portions of these elements inaccessible for visual inspection or the application of nondestructive testing techniques. This paper demonstrates that vibration-based damage detection (VBDD) is an effective alternative for monitoring their structural health. A box girder removed from a dismantled bridge was used to evaluate the ability of five different VBDD algorithms to detect and localize low levels of spalling damage, with a focus on using a small number of sensors and only the fundamental mode of vibration. All methods were capable of detecting and localizing damage to a region within approximately 1.6 times the longitudinal spacing between as few as six uniformly distributed accelerometers. Strain gauges configured to measure curvature were also effective, but tended to be susceptible to large errors in near support damage cases. Finite element analyses demonstrated that increasing the number of sensor locations leads to a proportional increase in localization accuracy, while the use of additional modes provides little advantage and can sometimes lead to a deterioration in the performance of the VBDD techniques. 1. Introduction Although there has been a growing awareness of the declining state of the civil infrastructure in North America for several decades, recent catastrophic bridge failures have highlighted both the severity of the problem as it relates to bridges, and the inadequacy of current inspection and monitoring practices to assess their condition [1]. More objective means for monitoring the structural health of bridges have been pursued for some time by the research community. While a number of local nondestructive evaluation (NDE) methods [2, 3] or global response-based methods [4¨C6] are either in current use or are at various stages of development, the application of a specific structural health monitoring (SHM) technique will be most successful when its capabilities are closely matched to the features and requirements of a particular bridge component. Vibration-based damage detection (VBDD) may be particularly well-suited to assessing the condition of precast, prestressed concrete box girders. This type of girder is commonly employed as a superstructure component for short and medium span bridges. Available in standard cross sectional dimensions and lengths, they are typically used in simple span construction, with multiple units arranged
%U http://www.hindawi.com/journals/ace/2010/280685/