摘要
Records of the May 12,2008 MS8.0 Wenchuan,Sichuan,earthquake from 27 stations of Shaanxi Digital Strong Motion Network are processed and analyzed,including baseline adjustment of acceleration traces,filtering,and calculations of velocities,displacements and acceleration response spectra.The results show that direction energy radiation of the large earthquake and horizontal inhomogeneous medium along the wave traveling path might both have some effect on the scattering degree of the attenuation of PGAH,besides influence of local site conditions.For the same intensity,the ratios of PGA /PGV are commonly small,on average about 5,which indicates that long period components are rich in ground motion.Intensities for most sites of the stations are within Ⅴ～Ⅶ.The larger one among PGAE-W and PGAN-S is quite close to their PGAH,which is less than 10% in relative deviation.The dominated waves are surface waves.The thicker the soil overburden is,the stronger the surface wave will be and the longer the shaking will last.Local site conditions have strong effects on ground motion,especially those of thick sediment filled-in basins,as they can significantly amplify long-period components.
Records of the May 12, 2008 Ms8.0 Wenchuan, Sichuan, earthquake from 27 stations of Shaanxi Digital Strong Motion Network are processed and analyzed, including baseline adjustment of acceleration traces, filtering, and calculations of velocities, displacements and acceleration response spectra. The results show that direction energy radiation of the large earthquake and horizontal inhomogeneous medium along the wave traveling path might both have some effect on the scattering degree of the attenuation of PGAH, besides influence of local site conditions. For the same intensity, the ratios of PGA/PGV are commonly small, on average about 5, which indicates that long period components are rich in ground motion. Intensities for most sites of the stations are within V -VII. The larger one among PGAE-W and PGAN-S is quite close to their PGAH, which is less than 10 % in relative deviation. The dominated waves are surface waves. The thicker the soil overburden is, the stronger the surface wave will be and the longer the shaking will last. Local site conditions have strong effects on ground motion, especially those of thick sediment filled-in basins, as they can significantly amplify long-period components.
