Abstract: Fujian Province is located in the southeast coast of China. Under the humid tropical environment, the weathering of residual soil slopes is common. The weathering will adversely affect mechanical properties of residual soils and further affect the longterm stability and duration of the residual soil slopes. The typical granitic residual soil samples from Fuzhou and Quanzhou were collected and the laboratory simulations of weathering conditions on soil sample from both areas were performed in the test chamber that both the humidity and temperature could be controlled. The effect of low temperature and high humidity environment on the deterioration of the shear strength properties of residual soil samples was investigated. The test results indicate, under the laboratory test conditions, the internal friction angles for both residual soils remained approximately unchanged. The shear strength and the cohesion of soil samples from both areas are reduced in power relationship with time. The degree of strength reduction and the contraction characteristics under low temperature conditions are related to the mineral composition of the soil samples. The weathering deterioration in 〖JP2〗Fuzhou soil samples is slightly greater than those sample from Quanzhou area.

Key words: Granitic Residual Soils, Humid Tropical Environments, Experimental Simulation, Shear Strength Deterioration, Deterioration Mechanism