“Giproruda” Institute (Saint Petersburg, Russia):

Abrosimova G. G., Head of Department, e-mail: info@giproruda.ru
Shakhnovskiy A. Yu., Chief Specialist

The sufficient costs on a construction of temporary (downhole) roads in the open pit and on the dump of Lomonosov diamond deposit are caused by two basic factors: the presence of weak soils in the overlain strata; the absence of hard rocks for crushed stone industry in nearest regions.
Specialists of Military-Technical University along with “Giproruda” Institute held a scientific-research work. On the basis of the work results, the application of geogrids reinforced pavements was the most efficient on the weak soils of temporary roads. This operation allowed to decrease the thickness of pavements to more than two times and to reuse to 90% of crushed stone.
The decisions on pavement constructions of temporary roads were made on the basis of analytical calculations and laboratory researching, which were carried off with die installation. The die installation was constructed specially to hold these experiments. The decisions were confirmed by natural researchings on experimental areas of «open pit — strata» technological road of M. V. Lomonosov ore dressing and processing enterprise.
The estimates show that the usage of geogrids makes it possible to decrease the yearly withdrawal of expensive crushed rocks from 1350 thousands of m³ to 670 thousants of m³, without taking in account its reusing. Due to the reuse of crushed rocks, the required withdrawal of crushed rocks could decrease to 150 thousands of m³.