Particle shape effect on interfacial properties between granular materials and geotextile.

This paper presents an experimental study investigating the effect of particle shape of granular soils on the shear strength characteristics via direct shear tests. Thirty direct shear tests were conducted on spherical and crushed sand mixtures with different proportions (i.e. 0%, 25%, 50%, 75% and 100%). The overall regularity (O_R) parameter of sand particles varies between 0.788 and 0.909, fairly reflecting the particle shape of sand mixture. A particular relation between O_R and maximum shear strength was found, namely that maximum shear strength increases with a decrease in O_R. Furthermore, a gradual increase was observed in the improvement factor (I_f) due to geotextile reinforcement with an increase in O_R except for S25C75, representing 25% spherical and 75% crushed sand, at high and low normal stress levels (i.e. 29 kPa and 116 kPa). The interfacial friction angle (ϕ) of sand mixtures is improved by geotextile reinforcement. Additionally, geotextile reinforcement caused an apparent increase in ϕ with decreasing O_R values. [ABSTRACT FROM AUTHOR]