지진가속도 계측기반 사장교의 안전성평가 기법 적용성 분석

Recently, much attention has been concentrated on the utility of seismic accelerometers installed and operated in accordance with the installation and operation manual for seismic accelerometers. However, at present, measurement data is either not used, or only maximum acceleration data is used. Therefore, it is necessary to come up with ways to utilize the measured data. Hence, in this study, we investigated the emergency safety assessment method using the seismic acceleration measurement data of a cable-stayed bridge, which is among the target structures waiting the installation of seismic acceleration meters. The target bridge was selected and three safety assessment techniques typical of recent research trends were applied to analyze the application problems and possible improvements. The results of the analysis showed that: 1) the error of displacement safety evaluation increased due to long-term behavior characteristics; and 2) safety evaluations using statistical indicators showed that the characteristics of kurtosis stabilized as the standard deviation increased. Because of this characteristic, safety evaluations using kurtosis will therefore be possible during daytime while there is heavy traffic; 3) safety assessments using the changes in natural frequency showed that the characteristics of the large variation in natural frequencies in higher modes is due to seasonal factors. It was determined that damage to the structure can be assessed through natural frequency of the first mode.