Abstract:Study on ground motion by blast excitation in the bedrock region has been carried out in China, but the similar study not in the loess regions. Up to now, we have not any data near source about earthquake effects during blast in the loess regions. Using a blast Work, the decay regularity of ground motion and the effects of topography and geonmorphy on the ground motion were studied in this paper. The comparative study on the ground microtremors characteristic and loess soil properties before and after the blast was carried out too.
The results were obtained that the blast ground motion decay regularity is very similar to that of the natural earthquake ground motion, and if the acceleration develops up to some value, the loess will be failure, and that acceleration(peak-peak)is approximatively equal to the intensity grade X (New Intensity Scale of China). The comparative observation at the time after and before blast excitation indicated that the peak value of the spactra were similar, and the dominant period of the spactra ware increased.
