Dynamic Tests on Large Cable-Stayed Bridge

An ambient vibration survey of the Humber Bridge was carried out in July 2008 by a combined team from the UK, Portugal and Hong Kong. The exercise had several purposes that included the evaluation of current technology for instrumentation and system identification and the generation of an experimental data set of modal properties to be used for validation and updating of finite element models for scenario simulation and structural health monitoring. The exercise was conducted as part of a project aimed at developing online diagnosis capabilities for three landmark European suspension bridges.Ten stand-alone triaxial acceleration recorders were deployed at locations along all three spans and in all four pylons during five days of consecutive one-hour recordings. Time series segments from the recorders were merged, and several operational modal analysis techniques were used to analyse these data and assemble modal models representing the global behavior of the bridge in all three dimensions for all components of the structure.The paper describes the equipment and procedures used for the exercise, compares the operational modal analysis (OMA) technology used for system identification and presents modal parameters for key vibration modes of the complete structure. suspension bridge operational modal analysis structural identification 4

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“…For a few examples (Cunha et al, 2001) free decay to impulsive or suddenly released load has been used.…”

Section: Dynamic Testing For Condition Assessment and System Identifimentioning

confidence: 99%

Ambient vibration re-testing and operational modal analysis of the Humber Bridge

Brownjohn

Magalhães

Cunha

2010

Engineering Structures

276

108

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“…Moreover, since ambient vibration tests do not interrupt service of the test structure (e.g., shutting down traffic during bridge testing), they can be used readily for long term continuous structural health monitoring applications. Ambient vibration tests have been successfully applied to a variety of bridge structures such as the Vincent Thomas suspension bridge (Abdel-Ghaffar and Housner, 1978), Golden Gate suspension bridge (Abdel-Ghaffar and Scanlan 1985), Roebling suspension bridge (Ren et al 2004a), Safti Link curved cable-stayed bridge (Brownjohn et al 1999), Vasco da Gama cable-stayed bridge (Cunha et al 2001), twin curved cable-stayed bridges on the north and south sides of Malpensa airport in Milan (Gentile and Martinez y Cabrera 2004), Brent-Spence truss bridge (Harik et al 1997) and Tennesse River steel arch bridge (Ren et al 2004b). In these studies, system identification based on ambient vibration test data provided accurate estimates of natural frequencies and mode shapes despite the relatively low amplitude of the measured vibrations.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Testing of Alfred Zampa Memorial Bridge

Conte

Moaveni

et al. 2008

J. Struct. Eng.

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This paper describes a set of dynamic field tests performed on the Alfred Zampa Memorial Bridge (AZMB), also known as the New Carquinez Bridge, which is located 32km northeast of San Francisco on interstate Highway I-80. The AZMB, opened to traffic in November 2003, is the first suspension bridge in the United States with an orthotropic steel deck, reinforced concrete towers and large-diameter drilled shaft foundations. The dynamic field tests described herein were conducted just before the bridge opening to traffic. They included ambient vibration tests, mainly wind-induced, and forced vibration tests based on controlled traffic loads and vehicle-induced impact loads. Four different controlled traffic load patterns and seven different vehicle-induced impact load configurations were used in the forced vibration tests.The dynamic response of the bridge was measured through an array of 34 uni-axial and 10 tri-axial forcebalanced accelerometers deployed along the whole length of the bridge. These dynamic field tests provided a unique opportunity to determine the dynamic (modal) properties of the bridge in its as-built ST/2006/025227, Revised Version: 06/07/2007 (baseline) condition with no previous traffic loads or seismic excitation. Such properties could be used to validate and/or update the finite element models used in the design phase of this bridge. They could also be used as baseline for future health monitoring studies of this bridge. At the end of the paper, the ambient vibration test data were used to identify the bridge modal parameters (natural frequencies, damping ratios and mode shapes) using the data-driven stochastic subspace identification method.

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“…These devices can be used to no contact measure of both small and large displacements. Their accuracy and dynamic range is also high [8][9][10][11] and thus, they can be used in a high variety of applications [12][13][14]. Unfortunately, these devices tend to be very expensive, what makes that they are not cost-effective for many applications.…”

Section: Monitoring Of Vibrations and Displacements Of Structures Undmentioning

confidence: 99%

Optical Scanning for Structural Vibration Measurement

Espinosa

Pérez

Ivorra

et al. 2011

URND

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High speed cameras are often used for monitoring impacts and fast dynamic processes on structures. However, quantitative information about these processes is usually obtained through other means like accelerometers or Doppler vibrometers. In this paper, we show that a proper arrangement of the experiment and the camera allows non contact measurement of the characteristics of the main displacement mode (amplitude, frequency and attenuation). An application is given for the analysis of structure damages after low speed car impacts. The method is low cost, fast and accurate, and it permits direct visualization and measurement of the movement of the vibrating body. KEYWORD

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Dynamic Tests on Large Cable-Stayed Bridge

Cited by 174 publications

References 4 publications

Ambient vibration re-testing and operational modal analysis of the Humber Bridge

Ambient vibration re-testing and operational modal analysis of the Humber Bridge

Dynamic Testing of Alfred Zampa Memorial Bridge

Optical Scanning for Structural Vibration Measurement

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