Spatial variation and stochastic modelling of seismic differential ground movement

✍ Scribed by Chin-Hsiung Loh; Yeong-Tein Yeh

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 705 KB
• Volume: 16
• Category: Article
• ISSN: 0098-8847
• DOI: 10.1002/eqe.4290160409

✦ Synopsis

Specially designed arrays of strong motion seismographs located near earthquake sources are required for engineering studies of near-source earthquake properties as well as spatial variation of seismic waves. The SMART-I array in Taiwan provides good records for this type of study. Based on the SMART-1 array data, the analysis of the principal direction of wave propagation and the space-time correlation of some events recorded by SMART-I have been studied. A stochastic model for predicting the differential ground movement was also developed. This stochastic model includes the effect of source characteristics, attenuation of wave passage and spatial correlation characteristics. The performance of this model is discussed and compared with the ground movement recorded by the SMART-1 array. From the present study, it is found that spatial correlations d o exist as seismic waves propagate across the array site. Generally, the loss of coherence in the direction ofpropagation can be explained by energy at the same frequency exhibiting a slightly different velocity within the measurement intervals. It is also concluded that the phase velocity of seismic waves and the corner frequency of the ground displacement spectrum are controlling factors in the prediction of the root mean square of differential ground displacement.