KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
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Modal Parameter Extraction of Seohae Cable-stayed Bridge : I. Mode Shape

서해대교 사장교의 동특성 추출 : I. 모드형상

  • 김병화 (경남대학교 토목공학과) ;
  • 박민석 (한국도로공사 도로교통연구원) ;
  • 이일근 (한국도로공사 도로교통연구원.한양대학교)
  • Received : 2008.01.22
  • Accepted : 2008.07.09
  • Published : 2008.09.30
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Abstract

This paper reports the mode shapes of Seohae cable-stayed bridge extracted by TDD technique. In order to record total 72 acceleration points in the vertical direction of the bridge deck, a custom made data acquisition system with LAN communication has been especially developed and a set of ambient vibration tests has been conducted. For the measured acceleration responses, total twenty four mode shapes up to 2Hz has been extracted by TDD technique. The extracted mode shapes include many new modes that have not been identified in the current on-line health monitoring system installed in the bridge. It is confirmed that TDD technique is the most effective in extracting the high resolution mode shapes on a particularly long span bridge.

본 논문은 서해대교 사장교의 보강형에 대한 고해상도 다점 모드형상을 TDD기법을 이용하여 추출한 사례를 소개한다. 상시진동에 대한 진동시험이 실시되었으며, 총 72개의 센서위치에서 수직방향 가속도 시간응답을 계측할 수 있는 계측 통신망이 구축되었다. 계측된 가속도 시간응답에 대하여 TDD기법을 적용하여 총 24차 수직방향 모드형상이 추출되었다. 추출된 모드형상은 현재 운용중인 상시모니터링 시스템에서는 계측되지 못한 많은 모드들을 포함하고 있다. 장대교량과 같이 대형구조물의 고해상도 모드형상 추출에는 다른 여러 가지 동특성 추출기법보다 TDD기법이 매우 효과적인 것을 확인 할 수 있었다.

Keywords

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