Abstract: The influence of sedimentary direction on the strength and volumetric change of dense sand was examined via series of triaxial conslidated drained shear test. Dense sand specimens with different sedimentary directions were prepared based on the capillary effect of sand. Test results revealed that sedimentary direction had obvious influence on the ultimate peak strength and volumetric deformation of sand when the direction changed between 0°~90°. When the sedimentary direction was close to the failure plane direction which is suggested as (45°+_φ/2), the shear band of sample developed earlier, leading to easier failure with lower peak strength and earlier residual stage. Furthermore, a fitting formula reflecting the relation between sedimentary direction and peak strength is put forward. The formula-predicted result well coincided with test result under different confining pressures. Studying the influence of sedimentary direction on strength is of importance to the research of initial anisotropy of sand.

Key words: sand, capillary effect, sedimentary direction, consolidated undrained, shear test, peak strength