Study On Relations Between Microstructural Characteristic And Macroscopical Mechanical Property Of Soil Of Fill Space In Tianjin Binhai New Area

Reclamation has become an important means to obtain land in Tianjin Binhai New Area, the planning fill area reach 400 square kilometers. Vacuum preloading is the main method to deal with hydraulic fill mud. However, the soil after vacuum preloading can meet the needs of project or not, or how to deal with the foundation the next step, which requires us to know the engineering properties of soil after vacuum preloading better. The microstructural characteristics of soil are the determinants of its macro-mechanical properties. Through the soil microstructure research, to a deeper understanding of soil engineering properties.In this paper, the object of study is the soil of 40m below the surface in the industrial port fill space of Tianjin Binhai New Area , its microscopic structure have been revealed, the link between microstructural characteristics and macroscopic mechanical natures has been established.Firstly , stratum has been divided in light of sedimentary facies and physical and mechanical properties. the size of the components, mineral composition and chemical composition of sediment have been analyzed, focus on dredger fill. In addition, statistics values of physical and mechanical properties of soil have been obtained through a series of indoor soil test.Secondly, the structural behaviour and strength of structure of mucky clay with different depth and cause of formation have been studied, which shows that they all have strong structural behaviour. And structural stability ratio has been used to depict structural behaviour.Thirdly, the paper analyzes SEM photos, getting micro-structure type of soil in this area. This paper makes quantitative research with five morphological character parameters and two array character parameters. Further, the fractal of micro-structural characteristics has been studied .Fourthly, the paper analyzes the relationship between micro-structure characteristic parameters and compression coefficient and shear strength parameters cohesion as well as internal frictional angle based on soft soil.Fifthly, the discipline of micro-structure characteristic parameters change by the load has been received through compression test and triaxial CU test .