Study On Dynamic Response Of Soil Under Dynamic Compaction

With the process of our country's industrialization accelerates,dynamic compaction(DC)is playing a more and more important role in urban construction.At present,many scholars have conducted a thorough and deep research on DC problems and great progress has been achieved.But there are still many problems to be studied.The paper analyzes the dynamic response of the homogeneous,viscoelastic,layered saturated soil by use of the Biot's theory and integral transformation methods.The studies of the paper contain the following parts.1.The Biot's equations are decoupled with Helmholtz vector decomposition as well as the Fourier and Hankel transform respectively.Combined with the boundary conditions,the general solutions of the displacement,stress and pore pressure in the frequency-wavenumber domain are derived.Then the general solutions in time domain are obtained through numerical inversion transform.The method is verified by the existing results and the effects of Biot's parameters on the saturated soil are also investigated.2.On the basis of the general solutions of the homogeneous saturated soil,standard linear solid model is introduced,and the response of the viscoelastic homogeneous saturated soil is obtained.The method is verified by a practical engineering example.Besides,the effects of the viscoelastic parameters are also investigated.3.On the basis of the general solutions of the homogeneous saturated soil,the analytical solutions of the layered saturated soil are derived by use of the transmission and reflection matrices method(TRM)under DC conditions.Then the DC experiments at different sites are explored.Besides,the response of the layered saturated soil under different combinations of shear modulus and layer depth respectively are studied thoroughly.4.Combing the Smoothed Particle Hydrodynamics Method(SPH)with Finite Element Method(FEM),a 3D FEM-SPH DC model is established.The numerical model is validated against an engineering case.Besides,based on the numerical model above,the high energy DC is studied carefully with different methods,energy level and hammers.