Abstract:
It is of great significance to analyze the seismic shaking conditions of coseismic rock avalanches in Gong County area. The area is just located in gentle stepped rock slope of hilly area of south Sichuan Province. A set of seismic stations,located into Wutong village of Gong County,captured a
MS3.1 earthquake. Based on the captured seismic data,a series of analysis are carried out. The results show the upper stepped rock mass can produce larger site amplification and resonance amplification than the lower stepped rock. Due to the development of fissures and joints in cliff,the PGA and Arias of inner section of the upper stepped rock reduced 1.73 and 2.20 compared to the cliff section. This indicates that cliff exists site amplification effect. The seismic duration of the inner section of the upper stepped rock(convex terrain) is 1.25 times of the referred point(the lower stepped rock and the concave terrain). This indicates that micro topography has seismic duration amplification.