Dynamic compaction method is a physical method in foundation treatment. It is a method of compacting deep soil by impact. It is a typical dynamic problem. Its principle is to use powerful compaction energy to force deep soil liquefaction and dynamic consolidation, so as to compact the soil, so as to improve the strength of foundation soil, reduce compressibility, and eliminate soil collapsibility, swelling shrinkage and liquefaction.

另外，对强夯法加固地基的机理认识，还应分宏观机理和微观机理。

In addition, the mechanism of dynamic consolidation should be divided into macro mechanism and micro mechanism.

(1)宏观机理从加固区土所受冲击力、应力波的传播、土的强度对土加密的影响作出解释。

(1) The macroscopic mechanism is explained from the impact force on the soil in the reinforcement area, the propagation of stress wave and the influence of soil strength on soil densification.

(2)微观机理，则对冲击力作用下土的微观结构的变化，如土颗粒的重新排列、连接作出解释。宏观机理是外部表现，微观机理是内部依据。

(2) The micro mechanism explains the change of soil microstructure under impact force, such as the rearrangement and connection of soil particles. The macro mechanism is the external performance, and the micro mechanism is the internal basis.

其次，应对饱和土和非饱和土加以区别。

Secondly, saturated soil and unsaturated soil should be distinguished.

从理论上讲，在好的夯击能作用下，地基土中出现的孔隙水压力达到土的自重压力，这样的夯击能称好的夯击能。在黏性土中，由于孔隙水压力消散较慢，当夯击能逐渐加大时，孔隙水压力相应叠加，因此可根据孔隙水压力增加值来确定好的夯击能。在砂性土中，孔隙水压力增长及消散过程仅为几分钟，因此孔隙水压力不能随夯击能增加而叠加，可根据大孔隙水压力增量与夯击次数的关系来确定好的夯击能。

Theoretically, under the action of good tamping energy, the pore water pressure in the foundation soil reaches the self weight pressure of the soil. Such tamping energy can be called good tamping energy. In cohesive soil, due to the slow dissipation of pore water pressure, when the tamping energy gradually increases, the pore water pressure will be superimposed accordingly. Therefore, the good tamping energy can be determined according to the increased value of pore water pressure. In sandy soil, the growth and dissipation process of pore water pressure is only a few minutes, so the pore water pressure can not be superimposed with the increase of tamping energy, and the good tamping energy can be determined according to the relationship between the increment of large pore water pressure and tamping times.