| Large amounts of slurried fine-grained soil are generated each year from mining, dredging operations, and treatment plants and they are deposited hydraulically into confined disposal facilities all over the world. The deposited material often has high water content, high compressibility, and low strength. The natural solidification processes of this material in the confined facilities including sedimentation, consolidation, and desiccation usually take decades to complete and require substantial areas of land. These lands are left unusable during the period of solidification and often pose a potential problem to the local ecosystem and hydrogeological system as well as the wildlife and human life.; In the solidification processes of these soft soils, the sedimentation and consolidation have been intensively studied for many years and many analytical as well as the numerical models of these two processes have been established. The soil desiccation process, on the other hand, is still not well understood in many aspects. In addition, the major soil desiccating momentum. the evaporation, also needs to be explored with respect to its effects on the top soil surfaces and soil cracks.; The goal of this research is to establish a comprehensive soil desiccation model and probe into the evaporation effect on soils. This research has completed the fundamental work for the soil desiccation study including the modified analytical model and numerical solution for the soils undergoing one-dimensional and three dimensional desiccation. The cracking mechanism and evaporation-soil interaction are also studied in this work.; The outcome of this research can assist the operation and management of the soil deposition facilities to reach the maximum capacity and to improve the deposition effectiveness. Further field study and laboratory tests are necessary to establish the material characteristics and site-specific parameters for the prediction of soil desiccation behavior. |
