The base stress distribution in a granular pile play a crucial role in the research of the physical characteristics of the particle system. There are many factors and their variations that affect the packing property of granular pile. In this paper, the effects of funnel height, particle size, particle shape, and packing method on the base stress distribution of the pile were experimentally studied by the localized source method. A stress dip phenomenon can be observed in all conical piles used in our experiments. An increase of funnel height weakens the stress dip to some extent, while a more irregular particle shape promotes the stress dip. Besides, the stress dip in a pile with middle particle size is minor compared to other two particle sizes. Compared to the free packing pile, the stress dip in a pile of confined packing is more evident with correlation to the arching effect and its stress shielding effect inside the silo.
 

granular pile,stress dip,particle size,particle shape,funnel height