Generally, a suction control apparatus is used to examine compression properties of unsaturated clay. This is usually carried out with a pore water pressure of 0 under condition of applying pore air pressure, which is...Generally, a suction control apparatus is used to examine compression properties of unsaturated clay. This is usually carried out with a pore water pressure of 0 under condition of applying pore air pressure, which is positive pore air pressure in a triaxial compression test. It is known as the Axis Translation Technique. However in this study, the suction control apparatus does not employ a method of controlling initial degree of saturation of specimen. The method for making specimen using micro wave is used to ensure a uniform distribution of water content of specimen （microwave oven method）. Consequently, both compression properties are similar to each other. Collapse tests were carried out using specimens under the microwave oven method and air dry state. As a result, it was found that the former does not result in collapse but the latter results in a significant amount of collapse. Such occurrence of collapse is dependent on the soil structure. Therefore, the equation of effective stress for unsaturated soil proposed Bishop should not neglect as an occurrence of collapse for unsaturated soils.展开更多
文摘Generally, a suction control apparatus is used to examine compression properties of unsaturated clay. This is usually carried out with a pore water pressure of 0 under condition of applying pore air pressure, which is positive pore air pressure in a triaxial compression test. It is known as the Axis Translation Technique. However in this study, the suction control apparatus does not employ a method of controlling initial degree of saturation of specimen. The method for making specimen using micro wave is used to ensure a uniform distribution of water content of specimen （microwave oven method）. Consequently, both compression properties are similar to each other. Collapse tests were carried out using specimens under the microwave oven method and air dry state. As a result, it was found that the former does not result in collapse but the latter results in a significant amount of collapse. Such occurrence of collapse is dependent on the soil structure. Therefore, the equation of effective stress for unsaturated soil proposed Bishop should not neglect as an occurrence of collapse for unsaturated soils.
