The effect of vacancies on the distribution of forces within a two-dimensional pyramid-shaped granular pile has been investigated. With a hexagonal array of vacancies the pile is stable in the absence of friction, and the force distribution can be calculated exactly. This shows that the vertical component of load acting on each grain of the bottom layer is identical.

• Received 24 May 1993

DOI:https://doi.org/10.1103/PhysRevE.48.4099