Abstract: The unconsolidated-undrained direct shear tests were carried out on the undisturbed and remolded granite residual soil samples, and the test curves between the moisture content and shear strength of the granite residual remolded soil in Guangdong University of Technology area were obtained. The experimental results show that, under the same water content and dry density, when the vertical pressure is less than the initial consolidation pressure, the cohesion of the remolded soil is less than that of the undisturbed soil, and the internal friction angle of the remolded soil is also less than that of the undisturbed soil. When the vertical pressure is greater than the initial consolidation pressure, the shear strength of the remolded soil is gradually close to that of the undisturbed soil; as the vertical pressure is greater than 135kPa, the shear strength of the undisturbed soil begins to be smaller than that of the remolded soil, and the internal friction angle of the remolded soil is larger than that of the undisturbed soil. In the comparison of the unconsolidated-undrained shear tests of granite residual remolded soil with different water content, the shear strength of soil increases with the increase of vertical pressure, the cohesion of remolded soil decreases significantly with the increase of water content, while the internal friction angle decreases slightly with the increase of water content.

Key words: Undisturbed Granite Residual Soil, Remolded Granite Residual Soil, Saturation, Unconsolidated-Undrained Direct Shear Test, Shear Strength