일체형교대교량의 지진취약도 평가에 적합한 지진강도지표

Efficient Earthquake Intensity Measure for Seismic Vulnerability of Integral Abutment Bridges

본 논문의 목적은 일체형교대교량의 지진취약도를 평가하는데 적합한 지진강도지표(IM)를 판별하는 것이다. 90개의 지진가속도기록과 20가지 IM을 고려한 비선형시간이력해석을 수행하여 교각의 횡방향변위를 관찰하였다. 교량의 내진성능과 상관도가높은 IM을 판별하기 위해 결정계수, 표준편차, 상관계수 등 다양한 통계인자를 고려하였다. 수치해석결과 상관도가 높은IM은 고유주기에서의 스펙트럼가속도, 스펙트럼속도, 스펙트럼변위와 ASI, EPA, PGA, A95 등으로 나타났다. 상관도가 높은IM를 기준으로 한 교량의 지진취약도곡선을 도출하였다.

The purpose of this study is to identify efficient earthquake intensity measures (IMs) for evaluating the seismic vulnerability of integral abutment bridges. A total of 90 ground motion records and 20 typical IMs were employed for the numerical analyses. A series of nonlinear time-history analyses was performed on the bridges to observe the lateral displacement of the bridge piers. Statistical parameters such as the coefficient of determination, standard deviation, and correlation coefficient were calculated to identify the strongly correlated IMs with the seismic performance of the bridges. The numerical results show that the efficient IMs are spectral acceleration, spectral velocity, spectral displacement at the fundamental period, acceleration spectrum intensity, effective peak acceleration, peak ground acceleration, and A95. Moreover, a set of fragility curves of the bridges was developed with respect to the efficient IMs.