چكيده لاتين
Clay soil, due to its low permeability and high compressibility, causes long-term settlement and low bearing capacity in projects. Conventional improvement methods are not very efficient in dealing with such soils and the consolidation process is slow. In this study, an attempt has been made to investigate the possibility of using the new electroosmosis technology in the consolidation of fine-grained soils. In this study, the role of the electric field in accelerating drainage, shortening the consolidation time, and changing the mechanical properties of the soil was evaluated. For this purpose, clay was collected from the city of Isfahan and its initial characteristics were determined. The samples were compacted with a moisture content higher than the optimal value and after 24 hours of saturation, they were subjected to voltages of 18, 24, 36, and 48 volts for 24 hours. The tests were performed in two modes without a slope and with a hydraulic slope. Also, to investigate the effect of ions, two additional tests of 24 and 36 volts were investigated with calcium chloride solution at concentrations of 0.5 and 1 molar. During the process, the settlement rate, the volume of water output, the electric current, and the changes in the pH of the electrolyte were continuously monitored, and at the end of the compressive-shear strength, the percentage of moisture remaining in the sample and the soil pH were measured. Also, in order to evaluate the effect of simultaneous loading, two 24 and 36 V tests were performed using a consolidation meter. The results showed that with increasing voltage, the settlement rate and pore water outflow increased, and the highest settlement was observed at a voltage of 36 V with the application of a hydraulic gradient. Under the same conditions, the compressive and shear resistance increased from the anode to the cathode side and was in line with the changes in soil pH. In addition to these changes in the type of fluid, the concentration of the solution and the hydraulic gradient also affected the mechanical behavior of the soil. However, the combination of mechanical loading and the application of an electric current, in addition to increasing the settlement rate, reduced the moisture content and improved the compaction resistance of the soil. Overall, the observations indicate that electroosmosis effectively plays a role in reducing the settlement time and improving the strength and stability of saturated fine-grained soils.
