Experimental study on creep behavior of reconstituted soft clay considering preloading effect

As a very soft and problematic engineering material, marine soft clay is characterized by high water content, low bearing capacity, and high compressibility, and widely distributed off the coast of Hangzhou city. It is of great importance to investigate the consolidation creep behavior for the group stability analysis. A series of one-dimensional consolidation tests were carried out on Hangzhou reconstituted soft clay specimens using the GDSAOS automatic oedometer to investigate the preloading effect on the creep behavior. The results indicate that the creep deformation of the soil increases with a decelerating rate during the multi-stage loading under different preloading conditions. The vertical strain and void ratio evolve in a similar trend during the primary consolidation. Preloading can be applied to increase the degree of soil consolidation, thereby improving the stability of structures in actual projects. The study found that the secondary consolidation coefficient depends on both the loading increment ratio and preloading conditions. The smaller the loading increment ratio, the more obvious the growth of the secondary consolidation coefficient in the later loading; the larger the preloading magnitude, the smaller the value of the secondary consolidation coefficient in the early stage of multi-stage loading. The research results have reference significance for the safety of structures in the same type of soft clay area.