METHOD FOR DETERMINING ROCK MASS BUMP HAZARD BY ELECTROMAGNETIC EMISSION, AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2014 - IPC E21C39/00 

FIELD: measurement equipment.

SUBSTANCE: invention refers to mining and is meant for evaluation of stress strain behaviour of rock mass section by recording pulse emission of electromagnetic oscillations. Method involves measurement of maximum amplitudes in roadway and maximum activity of electromagnetic emission on record threshold above the level of electromagnetic emission background. In the range of amplitudes from zero reading to maximum reading, calculated is A parameter as logarithmic mean value of distribution of pulses peak amplitudes. All the values of amplitudes of the specified range are divided into 10 unequal threshold in logarithmic progression in increment divisible by log₂. Bar chart of signals distribution is built in double logarithmical coordinates. Based on this bar chart calculated is B parameter as estimation of rise rate of pulses peak amplitudes above the threshold level. Dependence diagrams of parameter values A(x_i) and B(x_i) from station x_i location on roadway profile are built as well as diagrams of gradients of these parameters functions. Critical values of Acr and Bcr are determined as well as their total critical rate of change. Rock-bump hazardous considered are those sections where at least four of three inequations are realised simultaneously. Device contains series-connected electromagnetic sensor, preamplifier and amplifier, analogue-to-digital converter and digital processing unit with indicating unit connected to it. According to the method the device is additionally provided with low-frequency filter connected to series circuit between preamplifier and amplifier, series connected between amplifier and analogue-to-digital converter, the second low-frequency filter and high-frequency filter, as well as reference voltage source, and to digital processing unit connected is quick operating digital signal processor double connected to analogue-to-digital converter, double connected also to programs non-volatile memory, data flash-memory and USB-port.

EFFECT: improving accuracy and reliability of rocks dynamic fracture forecast, as well as reducing labour intensity and improving measurements processibility.

8 cl, 5 dwg