Research on the identification and engineering characteristics of recently deposited soils in the Tianjin Binhai New Area

Based on the analyses of the paleocoast line and the dating test, the formation age of the upper terrestrial sedimentary soil in the Binhai New Area is studied, the principle of the recently deposited soils in the area is determined, and the classification of the recently deposited soils is further divided according to the genetic type and sedimentary environment. Based on the thickness of the soil layer and the depth of the floor, the development and distribution of the recently deposited soils in the Binhai New Area is investigated, and the engineering characteristics of this type of soil are analyzed and evaluated. The results show that formation age of the upper terrestrial sedimentary soil in the Binhai New Area is less than 4000 years. Consequently, the soil should be classified as recently deposited soil. Together with the original recently deposited soil, the recently deposited layer formed in the area. According to new classification principle, the recently deposited soils can be divided into three types: flooded recently deposited soil, ancient channel recently deposited soil and upper terrestrial recently deposited soil. The thickness of the recently deposited layer generally ranges from 1 to 2 m, and the floor depth generally ranges from 3 to 4 m. The engineering properties are poor, and are characterized by higher water content, larger void ratio, lower shear strength and higher compressibility, and the foundation bearing capacity is generally 100 kPa or so.