Experimental investigation on electro-osmotic treatment combined with vacuum preloading for marine clay.

An electro-osmotic consolidation (EO) combined with vacuum preloading (VP) was investigated on marine clay using laboratory tests. To improve consolidation efficiency and reduce the settlement difference, a new prefabricated device was designed to combine EO and VP for the tests. The results indicated that the vacuum preloading with intermittent electro-osmotic consolidation (VP–I-ECM) provided more water discharge with higher discharge rate and produced larger soil settlement compared to traditional vacuum preloading and electro-osmotic consolidation. For the combined method, the VP effectively removed water from the soil for the first 12 h, and its efficiency decreased with the time. After 12 h, the intermittent EO was used to further consolidate the soil and maintain a high level of drainage rate. Test results also showed that the combined method of VP-I-ECM significantly improved the shear strength and bearing capacity of the marine clay to satisfy the construction requirements with a significant reduction in the anode erosion and the energy consumption. This research study provides useful information for the design guide and practical application of the combined technique for improving marine clay. • Vacuum preloading (VP) combined with electro-osmotic consolidation (EO) was investigated for marine clay improvement. • A new prefabricated device was designed to connect VP and EO with the improved efficiency in the construction. • Laboratory tests were conducted on marine clay using the combined method. • Three different techniques, including VPM, VP-ECM, and VP-I-ECM, were evaluated. • VP-I-ECM provided better consolidation efficiency and lower energy consumption. [ABSTRACT FROM AUTHOR]