While widen the highway foundation, due to it is still unclear that the law of dynamic compaction vibration impact on the original subgrade and foundation structure, which restricts the use of dynamic compaction technology in the highway foundation-broaden project. In this paper, by using the dynamic compaction indoor model test, simulated the dynamic compaction road widening foundation works, monitored the vibration acceleration of the pavement and subgrade surface in the process of dynamic compaction vibration, analyzed the dynamic compaction vibration propagation law of the roadside foundation in the subgrade structure. At the same time, we made the vibration amplitude of the key points and the rammer subsoil dynamic pressure value as double assessment indicators. Besides, we analyzed the dynamic compaction vibration response of subgrade under different parameters, evaluated foundation reinforcement effect. With research, under the same tamping energy and in a certain range of rammer diameter and weight, we had better choose small radius rammer and the compaction process of heavier rammers dropping from lower point, which can reduce the foundation dynamic vibration of the old subgrade and ensure foundation reinforcement effect.
