METHOD OF DETERMINING LONG-TERM STRENGTH OF MINE ROCKS

摘要

FIELD: mining engineering.;SUBSTANCE: invention relates to mining industry and can be used for determining a long-term strength limit of mine rocks by samples. A method determining a long-term strength of mine rocks is based on a regularity of changes in a damping time Δt_i of the acoustic emission at a gradually increasing loading of a sample. A mine rock sample is subjected to a graduated axial loading σ(t) in a uniform compression chamber at a constant lateral strain. The sample is kept at a specified known value of the axial stress on each loading phase until the parameters of the acoustic emission impulse flow are stable. Damping time Δt_i of acoustic emission activity N_Σi is determined on each loading phase of the sample. Difference of duration Δt_i-Δt_i-1 of the acoustic emission damping time is determined for each of its following and preceding loading phase. When the specified difference value is positive, an axial stress value of the preceding phase is recorded which is taken for the long-term strength limit of mine rocks.;EFFECT: enhanced accuracy of determining a long-term strength limit of mine rocks.;2 dwg