【摘要】 利用国内外287次5级以上的实际地震记录,研究了地震动有效幅值的不对称性特征及其规律。分别用有效幅值不对称比和有效幅值作用次数不对称比来描述地震动的不对称性,统计结果具有规律性,并提出了其估计公式。结果表明:地震动有效幅值不对称性和有效幅值作用次数不对称性特征明显,幅值不对称比的平均值不受震级影响,但与截断比呈非线性递增关系,截断比小于1/3时不对称比在1.07～1.20之间,截断比大于1/3时不对称比在1.13～1.96之间;有效幅值作用次数不对称比的平均值不受震级影响,但与截断比呈非线性递增关系,截断比小于1/3时作用次数不对称比在1.04～1.31之间变化,截断比大于1/3时作用次数不对称比在1.22～1.80之间。更多还原

【Abstract】 Using the records of 287 earthquakes,the magnitudes of which are greater than 5,the asymmetrical characteristics of effective amplitudes of ground motion are investigated.Using asymmetry ratios of effective amplitudes and effective cyclic numbers,the asymmetry of ground motions is described with regular results are regular,and its calculation formula is presented.The statistic results indicate that the asymmetrical characteristics of the effective amplitudes and effective cyclic number are obvious.The averages of asymmetry ratios of effective amplitudes are not influenced by magnitudes,but increase with the increase of cut-off ratios.The averages of asymmetry ratios are between 1.07~1.20 when the cut-off ratios are lower than 1/3,the cut-off ratios are higher than between 1.13~1.96 when the cut-off ratio are higher than 1/3.The averages of asymmetry ratios of effective cyclic number are not influenced by magnitudes,but increase with the increase of cut-off ratios.The averages of asymmetry ratios are between 1.04~1.31,when the cut-off ratios are lower than 1/3;the averages of asymmetry rations are between 1.22~1.80,when the cut-off ratios are higher than 1/3.更多还原