Abstract: Based on the domestic and foreign representative calculation methods of rockfall impact force, in view of the factors of impact force, a set of impact force testing equipment is designed. Different rockfall qualities, impact speeds, incident angles, properties and thickness of buffer material as influence factors are selected in experimental design to obtain the change rules of impact force. The results show that the maximum impact force gradually reduces with the decrease of rockfall weight or the lower impact velocity, the force in 2 cm thickness of buffer layer is reduced about 90% than without it; the buffering effect is obvious; and the maximum impact force reduces with the incident angle lowering; but the little decrease amplitude of impact force value as the incident angle become smaller. Combining with impact testing results, a calculation method of maximum impact force associated with each influence factor, is obtained. By checking, it is shown that the error is small, so it can provide certain reference basis for treatment design of rockfall hazards.

Key words: rockfall, impact force, calculation methods, physical simulation, treatment design