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.