• 한국지진공학회논문집
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• 제18권1호
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• pp.29-36
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• 2014

In industrial facilities sites, the conventional method determining the earthquake magnitude (M) using earthquake ground-motion records is generally not applicable due to the poor quality of data. Therefore, a new methodology is proposed for determining the earthquake magnitude in real-time based on the amplitude measures of the ground-motion acceleration mostly from S-wave packets with the higher signal-to-ratios, given the Vs30 of the site. The amplitude measures include the bracketed cumulative parameters and peak ground acceleration (As). The cumulative parameter is either CAV (Cumulative Absolute Velocity) with 100 SPS (sampling per second) or BSPGA (Bracketed Summation of the PGAs) with 1 SPS. The arithmetic equations to determine the earthquake magnitude are derived from the CAV(BSPGA)-As-M relations. For the application to broad ranges of earthquake magnitude and distance, the multiple relations of CAV(BSPGA)-As-M are derived based on worldwide earthquake records and successfully used to determine the earthquake magnitude with a standard deviation of ${\pm}0.6M$.

• 한국지진공학회논문집
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• 제16권1호
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• pp.37-45
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• 2012

지반가속도의 초당 최대값은 최근 제정된 지진재해대책법에 따라 지진기록계로부터 통신망을 통해 소방방재청으로 실시간 제공되어야 한다. 본 연구에서는 현재 PGA를 기반으로 한 신속한 지진피해통보 용도로만 고려되고 있는 지반가속도의 초당 최대값의 추가적인 활용성을 검토하고자, 국내외 강진자료 및 중소규모 지진자료에 대한 초당 100 샘플링된 지반가속도 자료의 1초 구간내 최대 절대값을 30초 동안 적산한 결과($BSPGA_k$)를 CAV(Cumulative Absolute Velocity) 및 진도 등과 비교하였다. CAV는 진도와의 높은 상관성으로 지진발생시 원자력발전소의 운전초과기준으로 사용되고 있으나, 계산시 초당 100 샘플링 이상의 많은 양의 지진파형 디지털 자료를 필요로 하는 단점이 있다. 비교 결과 $BSPGA_k$는 지진규모에 따른 지진동 수준과 상관없이 CAV와 전 범위에서 높은 상관성을 나타내었으며, 다수의 관측소가 연계된 지진관측망 운영시 유용하게 활용될 수 있는 신속 지진피해평가 지진동 파라미터로 확인되었다. 국내 중소규모 유감지진자료에 대한 지진진도 자료와의 비교결과, $BSPGA_k$-진도 상관식을 이용한 진도추정 오차는 CAV-진도 상관식의 진도추정 오차와 유사하였으며, PGA-진도 상관식보다 진도를 신뢰성 있게 추정하였다.

• Structural Engineering and Mechanics
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• 제41권1호
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• pp.1-24
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• 2012

A reinforced concrete (RC) framed structure detailed according to non-seismic detailing provisions as per Indian Standard was tested on shake table under dynamic loads. The structure had 3 main storeys and an additional storey to simulate the footing to plinth level. In plan the structure was symmetric with 2 bays in each direction. In order to optimize the information obtained from the tests, tests were planned in three different stages. In the first stage, tests were done with masonry infill panels in one direction to obtain information on the stiffness increase due to addition of infill panels. In second stage, the infills were removed and tests were conducted on the structure without and with tuned liquid dampers (TLD) on the roof of the structure to investigate the effect of TLD on seismic response of the structure. In the third stage, tests were conducted on bare frame structure under biaxial time histories with gradually increasing peak ground acceleration (PGA) till failure. The simulated earthquakes represented low, moderate and severe seismic ground motions. The effects of masonry infill panels on dynamic characteristics of the structure, effectiveness of TLD in reducing the seismic response of structure and the failure patterns of non-seismically detailed structures, are clearly brought out. Details of design and similitude are also discussed.