Abstract：The responses of the second period RCC of Qingjiang under blasting loading are analyzed by DEM first. The material parameters are obtained by comparing the numerical results and those of the experiments. And then，with these material parameters and some data obtained from experiments，the decaying rules of the vibration velocities with distance and time of the three period longitudinal cofferdam of the Three Gorges under blasting loading are analyzed. It is shown that the vibration safety of blast dismantlement for the third period longitudinal cofferdam of the Three Gorges is the most important problem. Therefore，it is practical and important to study the responses of vibration of the third period longitudinal cofferdam under blast loading.
