Study On The Large Strain Consolidation Theory On Partially Penetrating Sand Wells For Dredger Filling

Along with the development of the economy,the area constructed by land reclamation is increasing.On the one hand these projects have relieved the intensity in utilization of land,on the other hand some engineering problems appears.For instance:(1)The settlement calculated is largely different with the measured data.;(2)After consolidation,overlarge settlement affect the later construction etc.The main reasons are that the researches of under-consolidated ultra-soft soil foundation are insufficient and the effects of sand wells for under-lying layer are not considered sufficiently.According to the problems above,the consolidated characters of dredger filling were researched from experiments and theories.Some results are gotten:(1)The non-linear change of permeability coefficient and compression coefficient along with the void ratio and consolidated stress for the dredger filling which is improved from a small stress was researched.According to the experiment data,the models of permeability coefficient and compression coefficient were derived,which can consider the soil property.These models are the basis of large strain consolidation theory.(2)The boundary conditions and permeability consistent conditions were analyzed.Based on the large strain theory,the consolidation theory for partially penetrating sand wells foundation was derived,which can consider the soil layer under sand wells.The consolidation equations which considered two situations of ideal well and non-ideal well were established.(3)The consolidation equations which are derived in this paper were solved by compiling FDM programs.(4)An engineering from Tianjin was analyzed by using this paper's theory.A good predicting result was gotten,which illustrate the rationality of this theory.(5)Using this paper's theory,the consolidation process of consolidation layer and the underlying soil layer of sand wells was calculated.And the consolidation characters of this two layers was analyzed.(6)About "smear zone" in foundation with sand wells,this paper proposed three reasons which can introduce the phenomenon and verified that the variation of void ratio is a main factor to this.And the model of "smear zone" will change along with time.