Experimental Study On The Deformation Characteristics Of The Dredger Fill Under The Stress Paths Of Vacuum Preloading

In the era of rapid development of economy in our country,reclamation project has already become an effective way to solve the sharp contradiction between land and population.Vacuum preloading is an economic and feasible method in the process of the engineering application of reclaimed soil.The saturated dredger soil foundation is under consolidated,and it is in its liquid state,so the settlement could reach 3~4m in the process of reinforcement engineering.So the void ratio changes a lot in the process of reinforcement,and the coefficient of compressibility is always characterized by nonlinear.The traditional method cannot accurately reflect real soil subsidence.Theoretically,the dredger fill has been in over-consolidated after vacuum preloading,the foundation would display resilience.But the dredger fill foundation still has the settlement of 30cm~50cm after unloading Vacuum.The stress paths during the vacuum preloading were analyzed,and the deformation characteristics of the dredger fill had been studied in this paper.The main contents are as follows: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 studied.According to the experiment data,the models of permeability coefficient and compression coefficient were derived.2.By analyzing the deformation characteristics of the reclaimed soil foundation during the process of vacuum preloading and vacuum-surcharge preloading,the stress paths were obtained,which provides the basis for the next experimental study on the dredger fill.3.According to the actual stress path of vacuum preloading,a series of tests were designed and completed using the advanced GDS triaxial testing system and the improved advanced GDS triaxial testing system.With laboratory tests,the deformation characteristics of the dredger fill is discovered.4.Based on test results,study the deformation of soil after unloading vacuum stress when principal stress ratio is different.