Experimental study on the improvement of marine clay slurry by electroosmosis-vacuum preloading

Laboratory tests were conducted on marine clay slurry to investigate the feasibility and effectiveness of a combined electroosmosis-vacuum preloading method in tideland reclamation. This method consists of two main systems: the vacuum preloading system and the electroosmosis technique. In the vacuum preloading system, integrated prefabricated vertical drains (PVDs) are connected to the vacuum pipes directly through a new airtight cap to minimize vacuum loss. In this combined method, the electroosmosis technique is applied towards only the final stage of vacuum preloading, where both the dissipation of excess pore water pressure and the development of settlement have become slow. The test results show that the overall effect of this treatment on marine clay was enhanced significantly when electroosmosis was applied at the final stage of vacuum preloading, and the energy consumption in electroosmosis was only approximately 8% of the energy consumption in vacuum preloading.