Lessons from monitoring the performance of highway bridges

Abstract

Monitoring programs on four very different highway bridges originating from a range of requirements related to calibration of numerical models, assessment of load capacity and long term tracking of performance are summarized in order to draw out lessons relevant to the future development of structural health monitoring 'systems'. These lessons concern validation of structural models, appropriate methods for instrumentation, communication, data management and system identification. The paper presents experience obtained by collaboration in a form intended to educate, by example, bridge operators about potential and limitations of SHM systems.

Development of a structural health monitoring system for the life assessment of critical transportation infrastructure.

“…Forced vibration on a full-sized bridge structure has been induced various ways including an instrumented hammer (Lynch et al 2004), a specialized vibrating machine (Hsieh et al 2006), or even a person jumping on the structure (Brownjohn et al 2005). Excitation is often achieved with a specialized machine that spins an unbalanced weight and can be adjusted for loading amplitude and frequency.…”

“…Since the damage detection algorithms typically quantify changes in dynamic properties, many of the algorithms used for ambient vibration can also be used for forced vibration such as the modal assurance criterion (Brownjohn et al 2005). One method that is exclusive to forced vibration is the global flexibility index (GFI) which tracks the changes in the flexibility of the structure.…”

Experimental validation of a drive-by stiffness identification method for bridge monitoring

“…The need to assess and maintain the condition of bridge structures has influenced a considerable amount of research in the area of structural health monitoring (SHM) in recent years. [1][2][3]4 Increasingly, bridges are being instrumented for the purposes of vibration based monitoring, which in general focuses on modal parameters such as frequency and mode shapes. A number of authors [5][6][7] provide comprehensive reviews of vibration based damage identification and condition monitoring methods in the literature.…”

ARMA modelled time-series classification for structural health monitoring of civil infrastructure

“…The last two decades have seen a great deal of research and publication in the field of SHM and there has been a proliferation of SHM paradigms put forward [1][2][3], with longterm monitoring systems implemented on bridges in Europe, the United States and Asia [4][5][6]. This has provided a great deal of practical experience and knowledge and helped SHM reach a greater level of maturity.…”

“…ф(B) is the autoregressive function of order p defined in equation (2) and θ(B) is the moving average function of order q defined in equation (3). The autoregressive parameters are directly related to the system poles, λ i , i=1,2,…n through equation (4) [8]. For the case of dynamic structural response involving a number of vibration modes, n is twice the number of system modes excited and each mode is represented by a complex conjugated pair of poles.…”