The Study On Indoor Model Test Of Vacuum Reloading Associate With Chemical Agent

In recent years， in the process of channel regulation， the lake dredging， theland reclamation of our country， a large number of dredged soil come into being. Inthe coastal area development and construction， the vacuum preloading method hasbeen widely applied， it has been proved to have achieved good social and economiceffects.The way of the vacuum preloading associate with the chemical agent to the soil toconsolidate the dredged soil means to try to use the acts of Vacuum load and theeffects of the chemical agent to the soil to improve the mechanical property of thedredged soil. It can shorten the time of the Vacuum loading. The research of thismethod has great practical and research significance.After chemical reagent added to the dredged soil， the hydration reactionbetween the chemical agent and water will take place firstly. The hydration productswill make the soil particles agglomerate though its properties of adsorption andtractive efforts. The formation of the large aggregates will change the naturalsedimentation process of the soil particles though the Settlement law of Stokes.Different chemical agents will form different hydration products and differenthydration products will produce different effects to the progress of the naturalsedimentation of the soil particles.due to the usage of the chemical agents, theprocess and the effects of the consolidation differs to the traditional method ofvacuum preloading. In view of the above problems, this paper did some researchworks based on the research of the resource of dredged soil utilization of CCCCFourth Harbor Engineering Institute Co., Ltd. This paper is briefed as follows:(1) Designed and implemented the Indoor model test to simulate the vacuumloading construction site, analysed the relationship between the discharged water andmud surface settlement, the relationship between the vacuum degree in drainage plateand the pore water pressure in the soil, and how severity of the drainage plate hasbeen blocked by the soil particles.(2) Designed and implemented the sedimentation experiment, analysed thedifferent effects of four different chemical agents to the soil. The chemical agent S320has the best results in terms of the process of the natural sedimentation.(3) Designed and implemented the sedimentation experiment, analysed thedifferent effects of chemical agent S320to the soil which has different moisture content and different soil composition, did a comprehensive analysis of theadaptability of the chemical agent S320to the soil.(4) Designed and implemented the indoor model test of the vacuum preloadingassociate with chemical agent, The experiment was conducted for14days, analysedthe process of the soil consolidation and the mechanical properties of the soil aftervacuum unloaded. After chemical reagent added to the dredged soil the samplewhich has vacuum loaded after a term of14days natural sedimentation has the bestresults. In a short period of one day natural sedimentation, the sample with thechemical reagent added to the soil has much better consolidation effects than thesample with no chemical reagent added.