EXPERIMENTAL STUDY OF ELECTROOSMOSIS ROLE ON BEHAVIOR A GYPSEOUS SOIL

Abstract

Abstract Actually, the gypseous soil is such type of soil that contains a considerable amount of gypsum which may cause dramatic negative changes in its engineering properties when water vary. More precisely, the problem behind gypsum is the solution ability which dictates caves formation and excessive settlement foundation deteriorations for the civil engineering projects that include this type of soil. The electro osmosis is such technique in which water and other positive charged ions are migrated through application of direct electrical field from the positive anode to the negative cathode. Such application have many successful applications in geotechnical engineering like dewatering, electro grouting, capacity enhancement in pile driving and contaminant retrieval. The current study investigate the electro osmosis improvement behavior in gypseous soil through implementing an experimental program. Such program includes manufacturing a physical model to represent the foundation load application on a gypseous soil that experiencing a water rise and would be expected to collapse. The soil samples were prepared with dimensions of 30 cm x 30 cm x 25 cm and contained in 30 cm x 30 cm x 30 cm wooden box. This box was put in steel box of 50 cm x 50 cm by 35 cm to confine water. In addition, two soil of 30 % and 60 % gypsum contents were used in current study. Moreover, the role of applied voltage levels, electrodes II type, gypsum content, applied load and foundation dimensions were investigated through this program. The results showed that the electro osmoses technique may improve the surfaces settlement response for both soils. It is observed that the best voltage level is between 15 and 20 Volt of DC voltage. The maximum reported degree of improvement for 15 Volt was 70 % while in 20 Volt, such level may reach 80 % in some stations within the testing time. Additionally, it is proved that the copper illustrate the best performance among the selected types of electrodes and about 78 % degree of settlement improve