摘要
采用中日合作 ,分别布设于东川垂直竖井中地下 2 0 0 m、 1 0 0 m和地面 3个位置的高精度数字化地震仪记录的地方震资料 (震中距 8.5～ 95km,震级 ML1 .3～ 5.1 ) ,用频谱比的分析方法计算了东川地区不同深度 (- 1 0 0 m和地面 )的场地放大因子 .在 8个频率 (f =0 .75,1 .0 ,1 .5,2 ,3,4,6和 1 2 Hz)上所对应的在 - 1 0 0 m处的 3个分向 (N- S,E- W,U- D)的场地放大因子 (与 - 2 0 0 m处相比 ) ,当 0 .75 Hz≤ f≤ 2 Hz时 ,为 1 .0～ 1 .49;当 2 Hz<f <1 2 Hz时 ,为 0 .47～ 0 .99;在地面 ,3个分向在 8个频率上所对应的场地放大因子 (与 - 2 0 0 m处相比 )均大于 1 ,其值为 1 .6～ 7.63. - 1 0 0 m处的 S波和尾波场地放大因子与地面的 S波和尾波的场地放大因子的相关系数 ,当 0 .75 Hz≤ f≤ 2 Hz频段时 ,分别为 0 .82和 0 .81 ;当2 Hz<f<1 2 Hz频段时 ,分别为 0 .47和 0 .45.
WT5BZ]The digital seismometers with high accuracy are installed at depths of -200 m, -100 m in deep hole and on the surface in Dongchuan. By analysis of spectra ratio, the local events (with epicentral distances between 8.5 km and 95 km, magnitudes M L =1.3~ 5.1 ) recorded are used to calculate site magnification factor at different depths (-100 m and surface) in Dongchuan. Comparing results with that at the depth of -200 m, the site magnification factors at three components of N S, E W and U D corresponding to the depth of -100 m at 8 frequencies ( f = 0.75, 1.0, 1.5, 2, 3, 4, 6, and 12 Hz) are 1.0~1.49 when 0.75 < f <2 Hz and 0.47~0.99 when 2 < f < 12 Hz. On the surface, site magnification factors at three components are all greater than 1, i.e. between 1.6 and 7.63. The correlation coefficients of site magnification factors for S wave and coda at the depth of -100 m and on surface are 0.82 and 0.81 when 0.75 < f < 2 Hz, 0.47 and 0.45 when 2 < f <12 Hz, respectively.
出处
《地震学报》
CSCD
北大核心
2001年第1期68-78,共11页
Acta Seismologica Sinica
基金
日本京都大学和云南省科委国际合作处资助
