000009632 001__ 9632
000009632 005__ 20141205150225.0
000009632 04107 $$aeng
000009632 046__ $$k2008-10-12
000009632 100__ $$aCarvajal, Juan Carlos
000009632 24500 $$aSeismic Response of Bridges with Integral Deck-Abutments:Ambient Vibration Testing

000009632 24630 $$n14.$$pProceedings of the 14th World Conference on Earthquake Engineering
000009632 260__ $$b
000009632 506__ $$arestricted
000009632 520__ $$2eng$$aIntegral abutment bridges are single or multiple span structures consisting of a continuous concrete deck integrated with abutments and a flexible support system. These structures have become very popular due to the elimination of costly and maintenance prone expansion joints and bearings. However, the exclusion of joints causes the superstructure to interact more closely with the soil embankments, making the evaluation of vibration properties and seismic demands a process that involves many uncertainties. The purpose of this paper is to contribute to the better understanding of this type of bridges by investigating in detail their vibration characteristics at low levels of excitation. The paper presents the identification of modal vibration properties of six bridges with integral deck-abutments using ambient vibration tests. Results indicate that the motion of the embankments causes the superstructures of some single-span bridges to deflect with an operational mode similar to the first vertical natural mode of vibration. This behavior suggests that the seismic response of the bridges in the vertical direction may be strongly influenced by the seismic response of the embankments and the abutments. Steel bridges have developed thick cracks at the end of the approach slabs in the embankments. These bridges have the lowest fundamental frequencies of all the tested bridges. The presence of these cracks suggests that the abutment foundation may be too flexible for this type of superstructures. The identification of predominant frequencies of vibration of the embankments is done with a proposed technique named “cross response spectrum”. This technique is useful when the identification of predominant frequencies can not be easily determined by more traditional identification techniques such as the power spectral density and the H/V ratio.

000009632 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000009632 653__ $$anatural frequency, mode shape, modal damping, response spectra.

000009632 7112_ $$a14th World Conference on Earthquake Engineering$$cBejing (CN)$$d2008-10-12 / 2008-10-17$$gWCEE15
000009632 720__ $$aCarvajal, Juan Carlos$$iVentura, Carlos$$iHuffman, Sharlie$$iYao, Felix
000009632 8560_ $$ffischerc@itam.cas.cz
000009632 8564_ $$s398127$$uhttps://invenio.itam.cas.cz/record/9632/files/12-01-0171.pdf$$yOriginal version of the author's contribution as presented on CD, Paper ID: 12-01-0171.
000009632 962__ $$r9324
000009632 980__ $$aPAPER