Experimental Study On Composite Flocculants Combined With Vaccum Preloading To Reinforce Dredged Fill

It is known to all that early in the treatment of dredged fill,generally by sun-cure to make the soil reaches a certain strength,and then to use vacuum preloading.However,due to the reclaimed soil particles carried charge,make its existence is very stable,this directly led the natural drying speeds a long time,delay time limit for a project.In addition,due to reclamation silt clay is very fine in practical engineering,the late in vacuum preloading,dewatering plate forming dense soil around,continue to drainage difficulty,degree of vacuum in the soil mass attenuation is very big,the deep soil reinforcement effect is limited.In order to improve the problems that exist in the above project,put forward to land reclamation method of adding flocculants in silt soil,although the flocculation mechanism of the flocculants including electrical neutralization,the adsorption bridging,sedimentary sweep volume,etc.But considering the flocculating agent in the inorganic flocculants and organic flocculants,emphasis of the mechanism of action is not the same,even if a single flocculants in some kind of flocculants can to a certain degree as to enhance the strength of soil,if we can make full use of inorganic and organic flocculants flocculating effect,namely the inorganic organic composite flocculants,through the composite flocculants and the combination with vacuum preloading can achieve a rapid increase in early strength of soil,improving soil vacuum transfer efficiency,and ultimately improve the soil strength.The article mainly study from the measuring cylinder natural sedimentation test,single flocculants joint vacuum preloading,composite flocculants joint vacuum preloading specific research and so on,and the following conclusions are drawn:1.Dredged fill of different regions have big difference in the composition,physical properties,etc.This article is study on dredged fill in Wenzhou coastal region,providing a reference for other areas.2.Through measuring cylinder deposition experiment,flocculating effect difference between different flocculants is very big.Flocculating agent is added into the soil does not improve the flocculation body of settlement,but can be accelerated flocculation precipitation,especially the lime with the APAM composite flocculants is the best flocculation effect of all flocculants.3.Research reinforcement effect of several single flocculants combined with vacuum preloading on dredged fill.Inorganic flocculants in vacuum is generally better than that of organic flocculants,and comprehensive analysis of the flocculants' difference in displacement and pore water pressure,moisture content,vane shear strength,what can be thought is that lime and APAM is the best in inorganic and organic flocculants.4.By setting several groups of inorganic organic composite flocculants combined with vacuum preloading test,single flocculants in contrast analysis combined with vacuum preloading test,it can be seen:composite flocculants can be a very good play to its advantages of single flocculants,especially the shear strength increases obviously.In addition,lime and APAM composite flocculants show that it's the best of all composite flocculants.5.Compared to treatment effect of different dosage of lime and APAM combine with vacuum preloading,2%lime with 1%APAM is the best dosage combination.