ANALYZING SEISMIC SIGNAL FEATURES OF ROCKFALL IMPACT FRAGMENTATION: INSIGHTS FROM MODEL TESTING

As a common geological disaster type in mountainous areas,rockfall has obvious hidden,sudden and catastrophic characteristics. So far it is difficult to monitor or analyze the impact fragmentation process in a real-time way. The ground motion signals can indirectly reflect the seismic kinetic energy characteristics of the impact fragmentation process of the high rockfall events,and then invert the rockfall movement process. In this paper,a physical model test is carried out to collect the ground motion signal and study the relationship between the signal and fall height,volume and fragmentation degree. The results show that: (1)With the increase of the fall height or square amount,the Arias intensity becomes greater,which is the energy of the ground motion signal generated by the impact. (2)The runout distance of the accumulation deposit and covered area is proportional to the Arias strength. The stronger the ground motion signal energy is,the greater the runout distance of the accumulation deposit and the wider the covered area. (3)The degree of rockfall fragmentation is a key index that affects the runout distance and covered area of the accumulation deposit. The relationship among fragmentation degree,the ground motion signal energy and dynamic parameters are comparative analysed. It can be concluded that the greater Arias intensity,as well as the degree of rockfall fragmentation,the runout distance,and the covered area. The research can provide a new approach for the monitoring and early warning of high-level rockfall disasters in mountainous areas.