Engineering Characteristics of Deep High Liquid Limit Clayin Hangzhou Bay Area

Ningbo Hangzhou Bay Area is located on the south side of the Yangtze River estuary. The geological environment and hydrodynamic conditions are complex, and the sedimentary environment is variable. The high liquid limit clay layer is widely distributed within the range of 40~60 m below the surface of the area. This layer of soil is often within the range of deep foundation bearing layer of construction engineering. Studying the engineering geological characteristics of this layer of soil has important social and economic value for the development and construction of Hangzhou Bay New Area. The engineering characteristics of the deep high liquid limit clay were studied from the aspects of conventional geotechnical parameters, mathematical statistics, structural properties, damage model parameters, and triaxial CU test. The results show that: (1) The physical properties of Hangzhou Bay high liquid limit clay are characterized by high natural water content, large void ratio, high liquid limit, etc., but the mechanical properties are close to the second hard soil layer of the alluvial lake in Ningbo area. (2) The physical and mechanical parameters are basically normal distribution through numerical calculation software. The physical index parameters can be regarded as constants, and the mechanical index can be regarded as variables. Time and space variability and regional characteristics should be considered. (3) According to the test results, the Hangzhou Bay high liquid limit clay can be quantitatively calculated as under-consolidated soil with high sensitivity. The undisturbed soil shows the characteristics of stress softening, while the remolded soil shows the characteristics of stress hardening.