Physical and Mechanical Properties and BPNN Prediction Model of Silty Soil in Coastal Area of Jiangsu Province

Shallow soil deposits in coastal area of Jiangsu Province are mainly composed of silty soil and muddy silty soil that formed by Quaternary marine sediment or marine and terrestrial sediment. High groundwater level and poor geotechnical properties of the soil will directly affect the infrastructure construction and later operation safety. Based on the in-situ and lab test data of several new substation projects in coastal area of Jiangsu, the change ranges, variability and correlations of physical and mechanical characteristics of the typical silt soil were summarized. It shows that coefficient of variation of mechanical indexes (such as soil cohesion etc.) is about 0.5, which is significantly greater than that of physical indexes (such as soil density and liquid plastic limit etc.). A BPNN model of silty soil was constructed by using neural network method and the predicted result is good for reflecting the complex non-linear relationship between silty soil parameters. The prediction accuracy of soil compression indexes are better than that of shear strength indexes by using RMSE and MAE.