Research On Dynamic Characteristics Of Soil After Dynamic Compaction

Abstract:Because of the various advantages of the dynamic compaction, it has been widely used in all types of ground treatment works; However, due to the complexity of the soil, theoretical level of it is not reached the requirements of engineering practice. In order to make a great progress of the dynamic compaction theory, this paper summarizes the current research situation of the dynamic compaction method, and on the basis of the predecessors, reinforcing mechanism of fill foundation were made a further study.This paper uses ANSYS/LS-DYNA software create a three-dimensional solid model, the dynamic load is converted to triangular load; and it considers the material nonlinearity, geometric nonlinearity, large deformation of soil; Drucker-Prager model is used to constitutive model of soil. Then use it gets the data of the vertical stress, displacement and density, and made graphs in Excel. Through graphs the three parameters changing with the time at the first tamping and changing with the depth in other tamping were analyzed; and the effective reinforced depth of different compaction energy is studied. The results of numerical analysis show that energy level is higher and the changes of the maximum vertical stress values is greater at the same depth location; the upper soil gets a good improvement under a certain compacting number and the upper reinforcement effect gradually reduced in subsequent compacting, the main role is to transfer hammering stress.This paper combined with the testing data of engineering practice to verify the result of dynamic compaction numerical simulation; the result of validation shows that properties of a certain depth range of soil after a certain tamping times will not change a lot under subsequent lamping; it suggests that numerical simulation to coincide with the engineering practice.