Natural segregation of dumped stone materials: Fid-Bau Portal

Natural segregation of dumped stone materials

Radchenko, G. A.

Conclusion 1. Natural segregation of stone material inevitably occurs when dumping dry rock in layers, even of small thickness (4–5 m). 2. When the broken rock contains small fractions, including sand and fines, and the height of the dumped layer is appreciable, the small fractions accumulate in the upper part of the embankment and along with the stone components of the rock mass from the skeleton; in the lower part of the embankment are many cavities. 3. The small fraction pressed into the upper part under the effect of water or vibrations can migrate in time into the pores of the lower part of the stone embankment, as result of which settlement and deformation of the embankment occur. 4. The accumulation of the small fraction in the upper part of an embankment in quantities greater than 20–25% is not permitted for essential structures; for this purpose the height of the dumped layer is reduced or the voids in the lower part of the embankment are filled by washing in sand. 5. When dumping with washing (the water is delivered simultaneously with dumping) the height of the layer depends on the quantity of the small fraction in the original material. Washing of the dumped layer with the small fraction pressed into the upper zone does not yield results even at a quite appreciable water delivery rate.