Abstract：In order to analyze long-period characteristics of offshore ground motion, 893 3-component offshore ground motion records were selected, and horizontal and vertical offshore ground motions with obvious long-period characteristics were identified. The dynamic amplification factor spectrum of long-period offshore ground motion was compared with the aseismic design code spectrum, and correlations among offshore ground motion intensity indexes PGA, PGV, PGD and the maximum deformation demands of elastoplastic single-DOF systems with various strength reduction factors were studied. The analysis results showed that long-period characteristics of offshore ground motion caused by shallow source far-field strong earthquakes with focal depth less than 45 km, epicentral distance larger than 120 km and moment magnitude larger than 6.2 is very prominent, their dynamic amplification factor spectra in the long period range of 2-10 s are obviously exceed values of the aseismic design code spectrum, and long-period characteristics of vertical ground motion are more significant than those of horizontal one; the correlation between PGD and the maximum deformation demands of single-DOF systems is best in the long period range, so PGD is suggested to be the aseismic analysis intensity index for offshore far-filed long-period ground motion.
谭景阳,胡进军,谢礼立. 海域地震动长周期特性及其强度指标研究[J]. 振动与冲击, 2021, 40(3): 1-9.
TAN Jingyang, HU Jinjun, XIE Lili. Long-period characteristics of offshore ground motion and its and intensity index. JOURNAL OF VIBRATION AND SHOCK, 2021, 40(3): 1-9.
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