Physical model tests have been carried out in this study

to investigate the effect of fabric on angle of repose in granular piles. On the one hand

particles are deposited at various directions when constructing granular piles

to create different fabric characteristics; on the other hand

several leakage holes are set at the bottom of original (mother) granular piles to construct sub-piles (children piles) such that the effect of internal structures of mother pile on angle of repose can be examined. The results show that the angles of repose

? and ?

for the mother and children piles

respectively

decrease at first and then increase as the orientation angle ? of deposition plane varies from 0° to 90°

whereas the angle of repose ? ?shows an reverse variation trend. Note that the angle regions

where the minimum ? (or ?) and maximum ? occur

are complementary

respectively being ? = 30° ?45° and ? = 45° ? 60°. The analysis of the basis of a conceptual model leads to the finding that the more the deposition plane orientation approximates to the orientation of potential slipping surface

the smaller the angle of repose is

and the more the deposition plane orientation deviates

the larger the angle of repose is. The fundamentals underlying the observation that ?

?

and ? have their maximum or minimum values at special angle regions

are clarified. At last

a disturbance zonal model is proposed to account for the mechanism how the position of leakage holes (i.e. internal structure in mother piles) affects the angles of repose ? and ?.