Comparison and statistical analysis of engineering characteristics of marine soft soil in Nansha District of Guangzhou City based on in-situ tests

Based on a project in Nansha District of Guangzhou City, the physical and mechanical parameters of soft soil obtained from a series of laboratory tests and in-situ tests are compared and statistically calculated, and the variation laws of basic physical properties, strength parameters, deformation parameters and state parameters with depth of soft soil are analyzed. The results show that the soft soil in Nansha District is mainly silt and muddy soil with high water content and liquid limit. The overall strength of soft soil is insufficient, and the compressibility is high. The strength parameters such as penetration resistance, undrained shear strength and bearing capacity of foundation and the deformation parameters such as compression modulus, deformation modulus, undrained Young's modulus and horizontal subgrade coefficient have strong correlation with soil properties. In the silt layer, the parameters increase slowly, and the frequency distribution is concentrated, while in the muddy soil, the parameters increase rapidly, and the frequency distribution is uniform. The static earth pressure coefficient K₀ of soft soil is weakly affected by the soil layer, and the calculated value of China's railway code is more in line with the engineering practice than that of the Marchetti method. The soil is in medium-sensitivity state, and the bottom silt is in underconsolidation state, and the remaining soft soil is in overconsolidation state. The above results may enrich the researches on the in-situ engineering characteristics of soft soil in Nansha District, and provide the corresponding reference for the construction of soft soil projects in this area.