RU2542075C1 - Forecasting method of roof breaks and caving formations within section of preliminary mine working, which is not fixed with support (versions) - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention proposes two versions of a method - for a bottom-hole zone and a section remote from the bottom-hole zone. In both versions, measurements of amplitudes of pulses of electromagnetic interference signals (EMI) are made. Before EMI signals are recorded, a gauging station is formed to make measurements of values of amplitudes of EMI signal pulses, for which there used is a lead ball with a fastener at the height of 1.5 m, which is fixed in its roof rock, from soil of the working, thus arranging them along the vertical axis of this plane; after that, the specified device is arranged in front of the above fastener. Values of amplitudes of EMI signal pulses are measured; maximum values are chosen - N_max (Version 1) and N'_max (Version 2), which are compared to critical value N_cr of amplitude of EMI pulses along well horizon. If N_max>N_cr or N'_max≤N_cr, then, distance of the considered section is assessed as dangerous. Scaling of low-browed roof breaks and lumps of rock is performed with a tool. Operations are performed until N_max≤N_cr or N'_max≤N_cr is obtained.

EFFECT: improving accuracy of measurements by means of a single order of selection of measurement points, fixation of the number of counts and regular orientation of the chosen device.

6 cl, 2 dwg

Description

Technical solutions relate to mining and construction, namely to the forecast of dynamic manifestations in a rock massif upon a change in its stress-strain state, and can find application in rock geophysics, gasdynamics, geomechanics when monitoring and predicting dynamic manifestations in rock masses in the form pins and dumping.

A known method of protection against injury to miners involved in the preparation of mine workings in arrays of fractured rocks by erecting a temporary lining, including hanging on the tops of the lining, for example, long metal rods in the form of metal pipes, which move forward close to the mine face slaughter and they are laid on the tops of the fastening frames and flooring from scraps of blocks or puffs (V. M. Makarov, G. M. Kotov, V. A. Zuban. The use of temporary roof supports in the x development workings Kuzbass mines // Security issues in coal mines VostNII Transactions, v IX Publishing house "Nedra", M .: -... 1969 - s.244-253, Figure 4).

The disadvantage of this method is its high complexity and considerable time for assembling and disassembling such temporary lining before moving it forward after the next moving of the face, including the time to suspend the mentioned long rods, disassembling the ceiling and reassembling it after moving the rods, which makes it difficult to use the method in practice .

A known method of monitoring violations of the continuity of the massif of rocks by Auth. USSR No. 1101552, class E21C 39/00, publ. 07.07.84, BI No. 25, including the registration of electromagnetic radiation signals (EMP) along the length of the generation and measuring their duration, determining the average duration of pulses arising from the redistribution of rock pressure, which is taken as the reference, the selection of pulses of duration more than an order of magnitude exceeding the reference, and by their appearance they judge the occurrence of stratification.

The disadvantage of this method is that they do not record the amplitude of the EMP signals, and this reduces the reliability of the information received.

Closest to the proposed method in terms of technical nature and the totality of essential features is a method for predicting the destruction of rocks, implemented using the device for its implementation according to the patent of the Russian Federation No. 2137920, class E21C 39/00, G01N 29/04, publ. in BI No. 26, 1999

The method includes recording on the time interval the measurement of EMR signals and measuring their amplitudes, which determine the beginning of the destruction of the studied section of the array, while the time interval is divided into two unequal parts, measuring on each of them the values of the amplitudes of the pulses of the EMR signals at equal time intervals, Before loading the studied section of the array, the intensity of the measurement of the interference signal is determined by measuring the amplitudes of the pulses of the EMP signals over most of the measurement time interval, and the beginning of ment of destruction determined as loading test site array to implement the set ratio.

The disadvantage of this method is that the place of measurement in each specific mine and their number is chosen randomly, which affects the reliability of the measurements. In addition, the values of the readings for the said device depend on the orientation of this device at the time of measurement. Incorrect orientation of the device negatively affects the accuracy of measurements and, as a consequence, their reliability.

Technical task: improving the accuracy of forecasting pins and dumping by increasing the accuracy of measurements by a single procedure for selecting measurement points, fixing the number of samples and the correct orientation of the selected device.

The problem of the first embodiment is solved by the fact that in the method for predicting pitches and dumping within the unfastened section of the ongoing preparatory mine workings, including recording, within the section under study, the measurement of EMR signals and measuring the magnitudes of their pulses using a device for predicting fracture rocks according to the patent of the Russian Federation No. 2139920, publ. 09/20/1999, which are fixed at equal time intervals and by which they determine the beginning of the destruction of the unfastened section of the aforementioned mine working out, according to the technical solution prior to the registration of EMR signals within the unfastened section of the fortress, which represents the bottomhole zone of the preparatory mine working out, form a metering station for measuring the magnitudes of the amplitudes of the pulses of the EMP signals at a distance of 3 ÷ 5 m from the bottom of the said mine in the plane of its cross section, for which A plumb bob fixed in the rock of its roof is used with a retainer at a height of 1.5 m from the excavation soil, placing them on the vertical axis of this plane, after which the indicated device is placed in front of the retainer, orienting it horizontally with its long side perpendicular to the side walls of this excavation, and the length of time, for example, 1 minute, measure the amplitudes of the pulses of the EMP signals, making, for example, three counts in the first, second and third minutes of measurements, each time choosing the maximum values of N _{1m ax} , N _2max , N _3max . Additionally, measurements are also made of the magnitudes of the amplitudes of the pulses of the EMP signals at a height of 1.5 m from the soil of the mine along the contour of the bottom-hole zone of the mine with increments of, for example, 1.5–2 m: along the left side wall, along the face plane and along the right side wall, making three readings each time and then choosing from them the maximum values N _{l max} , N _{s max} , N _{p max} . After that, from the six maximum values obtained, the largest N _{max is} selected, which is compared with the critical value of the amplitude of the pulses of the EMP signals along the mine horizon, previously determined by the mine impact and prophylaxis service of the mine as the average for all mine measuring stations for this mine horizon. If N _max > N _cr , then the state of the considered bottom-hole zone is assessed as dangerous in terms of punctures and dumping. In this case, a frill of overhanging pins and pieces of roofing rock, side walls and bottom faces of the bottomhole zone under consideration is carried out using a tool adapted for such a frill, and at the end of the frill, the above operations are repeated until N _max ≤N _cr .

The physics of the rock destruction process includes the formation of microcracks and cracks, accompanied by the movement of electric charges on the banks of the cracks. The movement of charges is accompanied by EMP. The higher the growth of mechanical stresses, the higher the intensity of EMR.

The specified set of features allows to increase the accuracy of forecasting pins and dumping by improving the accuracy of measurements by using a single order of selection of measurement points and fixing the number of samples when using the above-mentioned device for predicting rock destruction according to RF patent No. 2137920 as an indicator of the pulse amplitudes of signals of an EMP of a deformable rock mass and with its help to establish the moment of formation of pins and dumping as due to an increase in the intensity of electromagnetic radiation signals, and due to light and sound signaling of said device.

Placing the specified device in front of the latch during measurements eliminates the influence on the accuracy of measuring the distance from the said device both to the roof and soil, and to the side walls of the mine, including during repeated measurements. Deviation of its position from horizontal and perpendicular to the side walls also affects the accuracy of measurements and, as a consequence, the reliability of measurements.

The choice of the three samples of the largest sharply reduces the likelihood of missing an increased count, which in these measurements is the main one and also contributes to the solution of the technical problem.

The formation of the metering station for measurements includes the selection of a specific cross section of the specified output within the measurement area. In practice, the length of the bottom-hole zone is usually 3–5 m according to the design of the ongoing preparatory mining.

The formation of the metering station streamlines the process of measuring EMR in the mine working both due to the location of the said device relative to the contour of the face and the side walls of the mine working, as well as due to the number of measurements. In addition, since the contour of the side walls and the bottom of the mine cannot be exactly the same in different measurement areas, and the mentioned device fixes each EMP measurement from a rather limited portion of the bottom contour and the side walls of the mine, repeated measurements with different orientations of the measuring device can greatly vary, which reduces the accuracy of the measurements. Additional measurements along the contour of the side walls of the section not secured by the lining ensure a more uniform distribution of the selected measurement points along the contour of this section. Accordingly, the accidental skipping of highly stressed zones of the contour of the specified section is minimized. All this is aimed at improving the accuracy and, as a consequence, the reliability of measurements, i.e. to solve the technical problem.

With additional measurements along the contour of the plot, three measurements were taken with a duration of 1 minute each. When taking measurements, it is necessary to: turn on the device, take a readout on the instrument panel, turn off the device, then turn it on again, take a second sample and turn it off again, etc. Since the numbers are constantly changing when the device is turned on, it is difficult for the operator to decide which number that appears on the screen to take as a reference, so you should wait a while when the numbers on the display stabilize. It is recommended to carry out three readings at the same time and select the maximum value from them. Taking three numbers while taking samples increases the total number of measurements, but provides an increase in the reliability of the forecast, which contributes to the solution of the technical problem. The choice of the three samples, the largest - maximum sharply reduces the likelihood of skipping the increased sample, which in these experiments is the main and also contributes to the solution of the technical problem.

It is advisable to measure the mentioned values of the amplitudes of the pulses of the EMR signals in the bottom-hole zone of the indicated mine working at the beginning of the shift and during each technological operation associated with the stay of workers in this bottom-hole zone before erection of the lining in it or the end of its repair, which allows timely during the work shift to receive information about the formation of pins and dumping to prevent injury to workers from accidental falling pieces of rock during the repair ntu lining on this site or on the construction of a new lining, which contributes to the solution of the task.

It is advisable to count on the said device with a time delay of 1 minute to stabilize its readings.

, $$N^{\text{'}}{}_{2\max }$$

, $$N^{\text{'}}{}_{3\max }$$

. Дополнительно проводят также измерения величин амплитуд импульсов сигналов ЭМИ на высоте 1,5 м от почвы выработки вдоль левой и правой боковых стенок рассматриваемого участка упомянутой горной выработки с шагом, например, 1,5÷2 м: вдоль левой боковой стенки и вдоль правой боковой стенки, делая каждый раз по три отсчета и выбирая затем из них максимальные величины $$N^{\text{'}}{}_{л\max }$$

и $$N^{\text{'}}{}_{п\max }$$

. После этого из полученных пяти максимальных величин выбирают наибольшую $$N^{\text{'}}{}_{\max }$$

, которую сравнивают с критической величиной N_кр амплитуды импульсов сигналов ЭМИ по горизонту шахты, определенной предварительно службой прогноза и профилактики горных ударов шахты как средняя по всем общешахтным замерным станциям для этого горизонта шахты. Если $$N^{\text{'}}{}_{\max }>N_{кр}$$

, то состояние рассматриваемого незакрепленного участка оценивают как опасное по заколам и вывалообразованию. В этом случае проводят оборку нависших заколов и кусков породы кровли и боковых стенок рассматриваемого участка, используя инструмент, приспособленный для такой оборки, а по окончании оборки повторяют перечисленные операции до тех пор, пока не будет получено $$N^{\text{'}}{}_{\max }\le N_{кр}$$

.According to the second embodiment, the solution to this problem is achieved by the fact that in the method for predicting pitches and dumping within the unfastened section of the ongoing preparatory mining, including recording within the section under study at a time interval the measurement of EMR signals and measuring the magnitudes of the amplitudes of their pulses using the device for forecasting destruction of rocks according to the patent of Russian Federation №2137920, publ. 09/20/1999, which are fixed at equal time intervals and by which they determine the beginning of the destruction of the unfastened section of the aforementioned mine working out, according to the technical solution, prior to the registration of EMR signals within the unfastened section of the fortress remote from the bottomhole zone of the ongoing preparatory mining, a metering station for measuring the magnitudes of the amplitudes of the pulses of the EMP signals in the aforementioned unfastened portion of the ongoing preparatory mining in the plane along cross section in the middle of this section. For this, a plumb bob fixed in the rock of its roof is used with a latch at a height of 1.5 m from the working soil, placing them along the vertical axis of this plane. After that, the indicated device is placed in front of the said latch, orienting it horizontally with the long side perpendicular to the side walls of this mine, and for the time interval of, for example, 1 minute, measure the amplitudes of the pulses of the EMP signals, making, for example, three counts in the first, second and the third minute of measurements, each time choosing the maximum values $$N^{\text{'}\text{'}}{}_{\mathrm{one}\max }$$

, $$N^{\text{'}\text{'}}{}_{2\max }$$

, $$N^{\text{'}\text{'}}{}_{3\max }$$

. In addition, measurements are also made of the magnitudes of the amplitudes of the pulses of the EMP signals at a height of 1.5 m from the excavation soil along the left and right side walls of the considered section of the mine working with a step, for example, 1.5–2 m: along the left side wall and along the right side wall making each time three counts and then choosing from them the maximum values $$N^{\text{'}\text{'}}{}_{l\max }$$

and $$N^{\text{'}\text{'}}{}_{P\max }$$

. After that, from the five maximum values obtained, the largest $$N^{\text{'}\text{'}}{}_{\max }$$

, which is compared with the critical value N _{cr of the} amplitude of the pulses of the EMP signals along the mine horizon, previously determined by the mine impact forecast and prevention service of the mine as the average for all mine measuring stations for this mine horizon. If $$N^{\text{'}\text{'}}{}_{\max }>N_{\mathrm{to}R}$$

, then the condition of the considered unsecured site is assessed as dangerous for pins and dumping. In this case, they carry out a frill of overhanging pins and pieces of rock of the roof and side walls of the section in question, using a tool adapted for such a frill, and at the end of the frill, repeat the above operations until it is received $$N^{\text{'}\text{'}}{}_{\max }\le N_{\mathrm{to}R}$$

.

The specified set of features allows to increase the accuracy of forecasting pins and dumping by improving the accuracy of measurements by using a single order of selection of measurement points and fixing their number when using the above-mentioned device for predicting rock destruction according to RF patent No. 2137920 as an indicator of pulse amplitudes of signals of EMP of a deformable rock mass and with its help establish the moment of formation of dangerous pins and dumping as due to an increase in the intensity of EM signals And the said device, and by providing sound and light signaling of this device.

Placing the specified device in front of the latch during measurements eliminates the influence on the measurement accuracy of the distance from the said device both to the roof and soil, and to the side walls of the mine, including during repeated measurements. Deviations of its position from horizontal and perpendicular to the side walls also affect the accuracy of measurements and, as a consequence, the reliability of measurements.

The formation of a metering station streamlines the process of measuring EMR in a mine, both due to the location of the said device relative to the contour of the side walls of the mine, and due to the number of measurements. In addition, since the contour of the side walls of the mine cannot be exactly the same in different measurement areas, and the mentioned device fixes each EMP measurement from a rather limited portion of the contour of the side walls of the mine, repeated measurements with different orientations of the measuring device can vary greatly, which reduces accuracy of measurements. Additional measurements along the contour of the side walls of the section not secured by the lining ensure a more uniform distribution of the selected measurement points along the contour of this section. Accordingly, the accidental skipping of highly stressed zones of the contour of the specified section is minimized. All this is aimed at improving the accuracy and, as a consequence, the reliability of measurements, i.e. to solve the technical problem.

With additional measurements along the contour of the plot, three measurements were taken with a duration of 1 minute each. When taking measurements, it is necessary to: turn on the device, take a readout on the instrument panel, turn off the device, then turn it on again, take a second sample and turn it off again, etc. Since the numbers are constantly changing when the device is turned on, it is difficult for the operator to decide which number that appears on the screen to take as a reference, so you should wait a while when the numbers on the display stabilize. It is recommended to carry out three readings at the same time and select the maximum value from them. Taking three numbers while taking samples increases the total number of measurements, but provides an increase in the reliability of the forecast, which contributes to the solution of the technical problem. The choice of the three samples of the largest - the maximum value sharply reduces the likelihood of missing an increased sample, which in these experiments is the main one and also helps to solve the technical problem.

It is advisable to measure the aforementioned values of the amplitudes of the pulses of the EMR signals within its unshielded lining of the indicated section at the beginning of the work shift and during it before each technological operation associated with the stay of workers within this section until the lining is erected or its repair is completed, which allows receive information on the formation of bins and dumping in a timely manner during the work shift in order to prevent injury to workers from accidentally falling pieces of rock during Boat Repair lining on this site or on the construction of a new lining for the entire shift.

It is advisable to count on the said device with a time delay of 1 minute to stabilize its readings.

The essence of the proposed variants of the method for forecasting pitches and dumping within the unfastened lining area of the ongoing preparatory mining is illustrated by examples of their implementation and the drawings of Fig.1,2. Figure 1 shows a longitudinal vertical section bB development in figure 2. In Fig.2 - the right section A ₁ -A ₁ (section "a") and the left section AA (section "b") in figure 1 (rotated 180 ° from right to left).

The method according to the first embodiment is implemented as follows.

The area not secured by the lining represents the bottom-hole zone of the ongoing preparatory mining (hereinafter referred to as the mining), section “a”. At a distance of 3 ÷ 5 m from the bottom, a metering station is formed for recording EMP signals in the plane of the cross section of the specified output. This plane is represented by a section A ₁ -A ₁ in figure 1, which is shown in figure 2 to the right. In this plane, a plumb line 1 is mounted, fixed with a benchmark 2 in the roof rocks (Fig. 2), with a latch 3 (Fig. 1), made in the form of a metal or plastic ball with an axial hole through which the plumb line is passed 1. Clamp 3 set at a height of 1.5 m from the soil of the excavation, and it serves to fix the position of the device 4 for predicting the destruction of rocks according to the patent of the Russian Federation No. 2139920 (hereinafter referred to as device 4). In Fig.1 marked pins 5 within the face, roof and side walls of the development.

Figure 1 in this particular case shows a wooden lining in the form of a trapezoid, consisting of racks 6, tops 7 and puffs 8. Along the contour of the development by hatching 9 (Figs. 1 and 2) lateral rocks are marked in which the considered development was carried out.

The operator, when taking measurements of the amplitudes of the pulses of the EMP signals, holds the device 4 in his hands at the level of the latch 3. The presence of the latch 3 allows the device 4 to be placed at the moment of measurement at a previously fixed point (including during repeated measurements).

Then, the device 4 is performed with a period of 1 minute 3 measurements, each of 3 counts. Of these, N _1max , N _2max , N _3max are selected one at a _time . Additionally, measurements are taken at a height of 1.5 m from the excavation soil along the contour of the bottom-hole zone with a step of 1.5 ÷ 2 m. In practice, this is one measurement on each of the three sides of the bottom-hole zone, and 3 readings are made each time, from which are selected for one of the largest values of N _{l max} , N _{s max} , N _{p max} . The recommended duration of each measurement is 1 minute. All readings during measurements must be entered in the measurement log. A total of 6 values will be obtained at the bottomhole station. They select the largest value N _max , which is compared with the critical value N _{cr of the} amplitude of the pulses of the EMP signals over the mine horizon, which was previously determined by the mine forecast and prevention service of mine shocks as the average for all mine measuring stations for the mine horizon under consideration. If N _max > N _cr , then the state of the considered bottom-hole zone is assessed as dangerous in terms of punctures and dumping. In this case, they carry out a frill of overhanging pins and pieces of roofing rock, side walls and the face of the bottomhole zone under consideration, using a tool adapted for such a frill. At the end of the frill, the above operations are repeated until N _max ≤N _cr . In practice, the above ratio is usually performed after the first frill, if this operation was carried out carefully.

The method according to the second embodiment is implemented as follows.

Section “c”, not secured by the lining, of the ongoing preparatory mining, is a section remote from the bottomhole zone by a distance “b”, where the lining is missing for various reasons (destroyed by high rock pressure, destroyed during blasting operations in the bottom of the mining under consideration, knocked out when transporting and other machines and mechanisms), or within the limits of this section, they intend to begin dissection to conduct new mining (in this case, the lining is removed).

In the middle part of this unfastened section “c” (Fig. 1) of the ongoing preparatory mine working in the plane of the cross section of this working, a measuring station is formed to measure the amplitudes of the pulses of the electromagnetic radiation signals. To do this, fix the benchmark 2 with a plumb line 1 and a retainer 3 (1, 2) in the working roof, placing it at a height of 1.5 m from the working soil. In front of the latch 3, an operator with a device 4 is placed, while the device 4 is placed horizontally, with the long side perpendicular to the side walls of the mine within the area "c".

, $$N^{\text{'}}{}_{2\max }$$

, $$N^{\text{'}}{}_{3\max }$$

. Все отсчеты при измерениях необходимо заносить в журнал измерений. Дополнительно проводят также измерения величин амплитуд импульсов в сигнале ЭМИ на высоте 1,5 м от почвы выработки вдоль левой и правой боковых стенок рассматриваемого участка упомянутой горной выработки с шагом, например, 1,5÷2 м: вдоль левой боковой стенки и вдоль правой боковой стенки, делая каждый раз по три отсчета и выбирая затем из них максимальные величины $$N^{\text{'}}{}_{л\max }$$

и $$N^{\text{'}}{}_{п\max }$$

. После этого из полученных пяти максимальных величин выбирают наибольшую $$N^{\text{'}}{}_{\max }$$

, которую сравнивают с критической величиной N_кр амплитуды импульсов сигнала ЭМИ по горизонту шахты, определенной предварительно службой прогноза и профилактики горных ударов шахты как средняя по всем общешахтным замерным станциям для этого горизонта шахты. Если $$N^{\text{'}}{}_{\max }>N_{кр}$$

, то состояние рассматриваемого незакрепленного участка «в» оценивают как опасное по заколам и вывалообразованию. В этом случае выполняют оборку нависших заколов и кусков породы кровли и боковых стенок рассматриваемого участка «в», используя инструмент, приспособленный для такой оборки, а по окончании оборки повторяют перечисленные операции до тех пор, пока не будет получено $$N^{\text{'}}{}_{\max }\le N_{кр}$$

.Measurements at the metering station in the area "b" is performed as follows. On a time period of 1 minute, the magnitudes of the amplitudes of the pulses in the EMR signal are measured, performing three counts of the values of the amplitudes of the pulses in the EMR signals in the first, second and third minutes of measurements, each time choosing the maximum values $$N^{\text{'}\text{'}}{}_{\mathrm{one}\max }$$

, $$N^{\text{'}\text{'}}{}_{2\max }$$

, $$N^{\text{'}\text{'}}{}_{3\max }$$

. All readings during measurements must be entered in the measurement log. Additionally, measurements are also made of the magnitudes of the amplitudes of the pulses in the EMP signal at a height of 1.5 m from the mine soil along the left and right side walls of the considered section of the said mine working with a step, for example, 1.5 ÷ 2 m: along the left side wall and along the right side walls, making each time three readings and then choosing from them the maximum values $$N^{\text{'}\text{'}}{}_{l\max }$$

and $$N^{\text{'}\text{'}}{}_{P\max }$$

. After that, from the five maximum values obtained, the largest $$N^{\text{'}\text{'}}{}_{\max }$$

, which is compared with the critical value N _{cr of the} amplitude of the pulses of the EMP signal over the mine horizon, previously determined by the mine forecast and prevention service of mine shocks as the average for all mine measuring stations for this mine horizon. If $$N^{\text{'}\text{'}}{}_{\max }>N_{\mathrm{to}R}$$

, then the condition of the unsecured section “c” under consideration is assessed as dangerous for pins and dumping. In this case, a frill of overhanging pins and pieces of roofing rock and side walls of the considered section “c” is performed using a tool adapted for such a frill, and at the end of the frill, the above operations are repeated until they are received $$N^{\text{'}\text{'}}{}_{\max }\le N_{\mathrm{to}R}$$

.

It is advisable to measure the EMP at the measuring station of section “c” at the beginning of the shift and during it before each technological operation associated with the stay of workers within the unsecured specified section, where the construction of the roof support or its repair is supposed.

It is also advisable to perform counts on the aforementioned device with a time delay of 1 minute to stabilize its readings.

Thus, the described variants of the methods make it possible to control the possibility of pinning and dumping, which ensures the fulfillment of the technical task to increase the reliability of forecasting pinning and dumping by increasing the accuracy of measurements by a uniform procedure for selecting measurement points, fixing their number and correct orientation of the device 4.

Claims (6)

1. A method for predicting faults and dumping within an unfastened area of a preparatory mine excavation, including registering within the study area at a time interval measuring electromagnetic radiation signals (EMP) and measuring the amplitudes of their pulses using a device for predicting rock failure containing a channel receiving and recording EMR signals with an amplifier and a recorder connected in series, an electromagnetic transducer-antenna, a pore former the burner voltage, detector, comparator, analog-to-digital converter and indicator connected to the output of the analog-to-digital converter, the input of which is connected to the output of the detector with the inputs of the comparator and threshold voltage generator, the output of which is connected to the second input of the comparator, the output the comparator is connected to an EMR signal recorder made in the form of a light and sound signaling device, and the detector input is connected to the output of the amplifier, to the input of which an electric an agnitic converter-antenna, while the amplitudes of the pulses of the EMP signals are fixed at equal time intervals and the beginning of the destruction of the unfastened section of the said mine working is determined by them, characterized in that prior to the registration of the EMR signals within the unfastened section of the support, which represents the bottomhole zone of the preparatory mountain generation, form a metering station for measuring the magnitudes of the amplitudes of the pulses of the EMP signals at a distance of 3 ÷ 5 m from the bottom of the said generation in p the flatness of its cross section, for which they use a plumb bob fixed in the rock of its roof with a retainer at a height of 1.5 m from the excavation soil, placing them along the vertical axis of this plane, then place the specified device in front of the retainer, orienting it horizontally with the long side perpendicular to the side walls of this mine, and for a period of time, for example, 1 minute, measure the magnitudes of the amplitudes of the pulses of the EMP signals, making, for example, three counts in the first, second and third minutes of measurements, Each time, maximizing the values of N _1max , N _2max , N _3max , additionally, measurements of the amplitudes of the pulses of the electromagnetic _radiation signals at a height of 1.5 m from the mine soil along the contour of the bottom-hole zone of the mine with increments of, for example, 1.5 ÷ 2 m: along the left side wall, along the face plane and along the right side wall, making three readings each time and then choosing from them the maximum values N _{l max} , N _{s max} , N _{p max} , after which from the six maximum values obtained choose the largest N _max, which is compared with critically the value N _{cr of the} amplitude of the pulses of the EMR signals along the mine horizon, previously determined by the mine forecast and prevention service of the mine as the average for all mine measuring stations for this mine horizon, and if N _max > N _cr , then the state of the bottomhole zone under consideration is estimated as dangerous for pins and dumping, in this case they carry out a frill of overhanging pins and pieces of rock of the roof, side walls and face of the bottomhole zone under consideration, using a tool adapted for such a frill, and about Onceanu ruffles repeat these operations until until a N _max ≤N _kr. 2. The method according to claim 1, characterized in that the said values of the amplitudes of the pulses of the EMP signals in the bottomhole zone of the indicated mine working is measured at the beginning of the shift and during it before each technological operation associated with the stay of workers in this bottomhole zone before erection in it support or the end of its repair. 3. The method according to claim 1, characterized in that the readings on the aforementioned device are produced with a time delay of 1 minute to stabilize its readings. 4. A method for predicting faults and dumping within the unfastened portion of the ongoing preparatory mine workings, including registering EMR signals within the study area over the time interval and measuring their pulse amplitudes using a rock fracture prediction device containing a signal reception and registration channel EMR with series-connected amplifier and recorder, electromagnetic transducer-antenna, threshold voltage driver, detector, an omparator, an analog-to-digital converter and an indicator connected to the output of an analog-to-digital converter, the input of which is connected to the output of the detector with the inputs of the comparator and the threshold voltage driver, the output of which is connected to the second input of the comparator, and the output of the comparator is connected to in the form of a light and sound signaling device to the EMR signal recorder, and the detector input is connected to the amplifier output, to the input of which an electromagnetic converter-ant is connected nna, while the amplitudes of the pulses of the EMP signals are fixed at equal time intervals and from them determine the beginning of the destruction of the unfastened portion of the said mine working out, characterized in that prior to the registration of the EMP signals within the unfastened portion of the mine remote from the bottomhole zone of the ongoing preparatory mining, a metering station in the middle of this section for measuring the magnitudes of the amplitudes of the pulses of the EMP signals in the said section mines in the plane of its cross section, for which they use a plumb bob fixed in the rock of its roof with a retainer at a height of 1.5 m from the excavation soil, placing them along the vertical axis of this plane, after which the said device is placed in front of the said fixer, orienting it horizontally long side perpendicular to the side walls of this mine, and for a period of time of, for example, 1 minute, measure the magnitudes of the amplitudes of the pulses of the EMP signals, making, for example, three counts in the first, second th and third minutes of measurements, each time choosing the maximum values

,

,

at the same time, in addition, they also measure the magnitudes of the amplitudes of the pulses of the EMP signals at a height of 1.5 m from the working soil along the left and right side walls of the considered section of the said mining with a step, for example, 1.5 ÷ 2 m: along the left side wall and along the right side wall, making each time three counts and then choosing from them the maximum values

and

after which, from the five maximum values obtained, the largest

, which is compared with the critical value N _{cr of the} amplitude of the pulses of the EMP signals along the mine horizon, previously determined by the mine forecast and prevention service of mine shocks as the average for all mine measuring stations for this mine horizon, if

, then the condition of the unsecured section under consideration is assessed as dangerous for pins and dumping, in this case, a frill of overhanging pins and pieces of roofing rock and side walls of the section under consideration is carried out using a tool adapted for such a frill, and at the end of the frill, the above operations are repeated until until received

. 5. The method according to claim 4, characterized in that the aforementioned values of the amplitudes of the pulses of the EMR signals within the specified section, not fastened by the support, are measured at the beginning of the work shift and during it before each technological operation associated with the stay of workers within this section before erection in it support or the end of its repair. 6. The method according to claim 4, characterized in that the readings on the aforementioned device are produced with a time delay of 1 minute to stabilize its readings.

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