In situ desaturation tests by electrolysis for liquefaction mitigation

Abstract

Electrolytic desaturation is a potential method for improving the liquefaction resistance of liquefiable foundations by reducing the soil saturation. In this study, in situ desaturation tests were performed to investigate the resistivity of soil at different depth and water level of the foundation under different currents. The test results show that at constant currents of 1, 2, and 3 A (ampere, unit of the direct current), the saturation of the treated foundation reached 87%, 83%, and 80%, respectively. During the electrolysis process, the generated gas migrates vertically and horizontally under the influence of buoyancy and gas pressure. In the end of electrolysis, the gas inside the sand foundation basically migrates vertically only. The higher current intensity employed for electrolysis will affect the uniformity and stability of the gas. At constant currents of 1, 2, and 3 A, the difference between the maximum and minimum degree of saturation in the treated foundation was 14%, 18%, and 19%, respectively; and after electrolysis had been halted for 144 h, the saturation in the treated foundation was 90%, 85%, and 87%, respectively. The electricity consumption analysis indicates that the desaturation method has excellent economic benefits in the treatment of saturated sand foundations.