Abstract: The particle size distribution curves show that, there are few fine sands and silts in the investigated granite residual soils. And the unique grain size gradation of the granite residual soil results in large discreteness of the parameters commonly used in design with physical parameters. Based on engineering geology investigation reports of metro engineering in Xiamen, correlation analysis are carried out between physical state parameters such as the interfine void ratio, the granular composition and the strength parameters. Results show that, correlative equations, of residual gravel cohesive soil and residual sandy cohesive soil, can be established between intergranular state parameters, proposed by Thevanayagam, and modulus of compressibility, in which, the modulus of compressibility decreases with increasing of the interfine void ratio. And, as for estimating shear strength indices, the characteristic diameter ratio can be taken as a parametric variable. With increasing of the characteristic diameter ratio, the cohesive force increases, and the internal friction is just the opposite. The established empirical formulas of modulus of compressibility, and shear strength indices for granite residual soil in this paper, can be provided as a reference for engineering design in Xiamen.

Key words: granite residual soil, key parameters, inter?ne void ratio, ratio of coarse particles to fine, characteristic diameter ratio