Particle Size Effect of Anchor Problem with Granular Materials

Abstract

In this study, the difference in the scale effect on shallow anchors in dense Toyoura sand, Soma sand and Leighton-Buzzard sand was evaluated by comparing the experimental result with the results of finite element analysis. A shear band thickness was introduced in this finite elemet analysis, so as to evaluate the particle size effect due to shear banding. In the experimental result, up to 10cm of anchor diameter (D), there was clear evidence of a scale effect in Toyoura sand, but there was a negligible scale effect in Leighton-Buzzard sand. In the finite element analysis, in the case of evaluating the scale effect using D, an effect was observed for D over 5cm in Toyoura sand, over 20cm in Soma sand and over 30cm in Leighton-Buzzard sand. Next, in the case of evaluation on using D/d₅₀ (d₅₀: mean particle diameter), within the range 350 to 1000 for D/d₅₀, there was clear evidence of the particle size effect. For D/d₅₀ over 1000, the trend of the scale effect was similar in all cases. The results indicate that it is necessary to consider the particle size effect when evaluating the scale effect due to progressive failure.