Abstract:
This paper presents a study on strength anisotropy in a sandy material with
anisotropic fabric formed by press loading. Two series of DS-CD tests (direct shear tests
under CD condition) were performed using a developed DS apparatus with a double-jack
system. To maintain anisotropic fabric in a sample, a freezing technique was developed. Shear
strength of samples in the active shear zone was found to be stronger than that of the passive
zone, and the results could be expressed well by an ellipse equation with tilting coordinates of
an angle measuring 15° to the horizontal line. To find a reason for the inclination of the axis
of strength ellipses, a 2D-DS test was performed by a developed 2D-DS device. The direction
of the main shear zone of a sand sample measuring 15° coincided well with that of the ellipses’
coordinates, which should be taken into consideration when shear strength from a DS-CD
test should be used in a safety analysis of a soil structure.
