Study On Mechanical Properties Of PVA Reinforced Cement Solidified Dredging Soil

Dredged soil,as a reusable resource,currently adopts random dumping methods,which will not only cause waste of resources,but also have an adverse impact on the ecological environment.Comprehensive utilization of it can effectively promote the sustainable health of the social economy development of.This paper is based on the characteristics of high moisture content,low strength and poor permeability of the dredged soil in the middle and lower reaches of the Yangtze River.In order to reduce the water content of the dredged soil,increase the strength of the soil,and improve the permeability of the soil,the method of solidification with fiber reinforced cement is mainly used for demonstration explore.From four perspectives of static strength,dynamic strength,permeability and microscopic,discuss and analyze the factors of fiber dosage,length modulus and maintenance age,and establish the relationship between static and dynamic,penetration and microscopic,and dynamic and static micro,An experimental study on the mechanical properties of PVA reinforced cement solidified dredged soil was conducted.Provide some practical application value test data and feasibility suggestions for reinforcement projects such as slopes,foundation cushions and retaining walls.The main work and results of this study are as follows:(1)The static characteristics of PVA reinforced cement solidified dredged soil.Through static triaxial test,the static strength characteristics of fiber reinforced cement solidified dredged soil were studied,and the stress-strain curve characteristics of different fiber incorporation and confining pressure on solidified dredged soil were studied,and the shear strength of the samples under different dosages and lengths was obtained.Index,the results show that the best blending amount of fiber is 0.1%,the length modulus is 6mm,and it also has a high degree of fit with the Duncan-Chang model.(2)The dynamic characteristics of PVA reinforced cement solidified dredged soil.Through dynamic triaxial test,the dynamic strength characteristics of fiber reinforced cement solidified dredged soil were studied.The number of cyclic vibrations and dynamic stress under different fiber dosage and length modulus were analyzed to obtain the dynamic strength curve.The results showed that the optimal fiber dosage It is 0.2%,the length modulus is 9mm,and combined with the static part of the comparative analysis,it can be concluded that the presence or absence of fiber in the compressive capacity plays a decisive role in the sample,and the length of the fiber in the tensile capacity of the sample Has a critical impact.(3)Study on permeability of PVA reinforced cement solidified dredged soil.Through the self-made RST-1 flexible wall triaxial permeability test,the permeability characteristics of the fiber reinforced cement solidified dredged soil were studied.The permeability coefficients of the soil under different dosages and length modulus were measured.It was found that the permeability coefficient decreased by an order of magnitude.The permeability of the sample has the characteristic of significantly increasing,and the anti-seepage effect is the best when the amount of fiber is 0.1%.(4)Study on the microstructure of PVA reinforced cement solidified dredged soil.This article uses the MATLAB tool to process the pictures taken by the electron microscope scan,and studies the surface microstructure of the fiber reinforced cement solidified dredged soil through the electron microscope scan test.From the spatial structure calculation,the distance between the voids,the planar porosity and the porosity are calculated and analyzed.The connection between microcosm and penetration and between dynamic and static micro.