Instantaneous Ground Deformation Estimation of Single Tamp Consolidation of Quasi-Saturated Fine Grained Soils

The transient deformation of single tamp was assumed as confined deformation. The volume change of void atmosphere was analyzed by Boyle law. On the basis of the relationship between effective reinforced depth and influential depth and tamping settlement,attenuation coefficient of void atmosphere with depth was calculated. Computation model of tamping settlement was studied. The reliability of the model was verified by an engineering project. The effect of saturation degree and void ratio of soil mass before tamping and impact energy on the displacement model of single tamp and efficiency of compact energy was studied. The displacement model of dynamic consolidation could be described by maximum of variation of porosity ratio and attenuation coefficient( β) of additional pore air pressure with depth. The results indicate that β is not related to void ratio and related to saturation and compact energy. The impact efficiency decreases when tamping energy increases. The optimal compact energy is assumed as maximal curvature Kmax of impact efficiency-compact energy diagram. The relationship between optimal compaction energy and saturation and void ratio is analyzed. The optimal compact energy decreases when the saturation degree is increased and the porosity ratio decreased.