Influnce Of Flocculation Conditioning On The Consolidation Characteristics Of Treated Mud

In China,a huge amount of dredged mud is generated every year,in order to improve the treatment efficiency of dredged mud,some scholars have proposed flocculation combined vacuum preloading technology and physicochemical treatment technology.Now the research related to the new technologies still stays at the level of improving the efficiency of dredged mud treatment,and there are few studies on the use of the dredged mud storage yard as a site or filler after treatment.In view of this,this paper focuses on the study of the consolidation and deformation characteristics of the treated mud after flocculation conditioning through geotechnical tests,aiming to provide theoretical support for the treated mud to be used as a filler in practical engineering.Specifically,the main test contents and results of this paper are as follows:(1)Carry out flocculation-surcharge preloading test to simulate the drainage consolidation process of"flocculant-dredged mud"mixed slurry with different proportions.The results show that the addition of flocculant can significantly improve the efficiency of drainage and consolidation of dredged mud and greatly shorten the preloading time.(2)The mud samples with similar void ratios after preloading were selected to carry out the one-dimensional consolidation compression test to explore the effect of flocculants on the consolidation characteristics of dredged mud.The results show that the addition of flocculants can increase the structural yield stress of the pre-compressed mud,but it will cause the pre-compressed mud to show higher compressibility.In addition,different types of flocculants have different effects on the secondary consolidation coefficient(C_α)of dredged mud after preloading treatment.(3)Carry out the strength test of the dredged mud treated by the physicochemical treatment technology.On this basis,select samples with similar undrained shear strength after 28 days of curing to carry out the high-pressure consolidation test to explore the effect of flocculation conditioning on the consolidation deformation characteristics of cement-solidified dredged mud.The results show that:the effect of flocculation conditioning has improved the compressibility of cement-solidified dredged mud.Different flocculants have great differences in the improvement of the structural yield stress of cement-solidified dredged mud.For the dredged mud conditioned by flocculation and cement,the C_αis generally smaller than that of the cement-solidified dredged mud.(4)X-Ray Diffraction(XRD)tests and Scanning Electron Microscope(SEM)tests are also implemented to explore the microscopic mechanism of the effect of flocculant on the consolidation and deformation characteristics of cement-solidified dredged mud.The results show that:compared with cement-solidified dredged mud,the solidified dredged mud after flocculation conditioning has no substantial changes in its products.However,the incorporation of flocculants can effectively promote the development of hydration products and change the microstructure of the solidified dredged mud.