Abstract: The physical and mechanical indices of the soft clay are the basics for the ground treatment and the engineering construction. The differences in the soft clay sedimentary environment at different areas will lead to the strong regional characteristics of the physical and mechanical indices. In this study, the Dongguan coastal soft clay was taken as a study object and the test results of nearly 450 groups of soft clay samples from the municipal road investigations were collected and analyzed by the mathematical statistics method. The correlations between the water content and the other physical and mechanical indices were also studied. The results show that the Dongguan coastal soft clay samples have the characteristics of high moisture content, high void ratio, high compressibility, and low shear strength. The frequency distribution of the consolidated undrained shear strength indices are relatively uniform, but the frequency distribution of the other physical and mechanical indices are concentrated and do not conform to the normal distribution pattern. The misture content has significant influence on the physical indices such as dry density, void ratio, liquid limit, plastic limit and compression coefficient. Compared with the direct undrained shear strength indices, the consolidated undrained shear strength indices have a greater correlation with the water content.

Key words: Coastal Soft Clay, Physical and Mechanical Indexes, Mathematical Statistical Analysis, Correlation Analysis