In order to study the disintegration mechanism of unsaturated granite residual soil

a serious of samples with different moisture contents and compaction degrees are made from granite residual soils from Guangzhou

south of China. Homemade apparatus is used for test

and meliorated method and computation formula were utilized for analysis. This meliorated method considered gas evolution during immersing into water so as to reduce the avoidable errors. Meanwhile

simplified model of particles with low degree of saturation is analyzed from the microscopic perspective. The disintegration mechanism of unsaturated granite residual soil is analyzed. The main controlling factors had been regarded as effective void ratio and matric suction. Relationship between above two control factors and disintegrating velocity has been established on the basis of effective void ratio analysis and estimation of soil water characteristic curve (SWCC). The results reveal that it shows exponential function and logarithm function relationships respectively.