FIELD: mining industry, particularly, determination of general toughness factor of permafrost coarse detrital rocks. SUBSTANCE: method includes testing of samples of permafrost coarse detrital rocks for ultimate axial compressive strength with subsequent division by 10 according to M.M. Protodyakonov method. After testing specimen is weighed, dried, separated by sieve method into separate fractions. Then separate coarse detrital fractions sizing above 2 mm are separated from filter and per cent content of each coarse detrital fraction is determined relative to their total volume which is used for determination of toughness factor of rocks comprising sample, and value of toughness factor of specimen itself is determined by summarizing of toughness factors of rocks and filler comprising sample by said mathematical expression. EFFECT: higher accuracy of determination of toughness factor of permafrost rocks. 2 tbl
