Small coal pillar gob-side entry driving advanced area impact danger prediction method

Abstract

The invention discloses a small coal pillar gob-side entry driving advanced area impact risk prediction method. The method comprises the following steps: collecting micro-seismic data of a mine mining working face; according to the micro-seismic data, respectively calculating an energy superposition value in the micro-seismic trend direction of the stope face of the upper section and an energy superposition value in the micro-seismic trend direction of the driving face of the lower section; performing correlation analysis on the energy superposition value of the micro-seismic trend direction of the stope face of the upper section and the energy superposition value of the micro-seismic trend direction of the driving face of the lower section; and performing impact risk prediction on the to-be-excavated area of the lower section by using the negative correlation area. The invention provides a small coal pillar gob-side entry driving advance area impact danger prediction method, which can judge a mine pressure abnormal area in a lower section during gob-side entry driving of a small coal pillar in the same area according to the distribution characteristic of an energy superposition value in a micro-seismic trend direction of a stope face of an upper section. And a guidance basis is provided for judging the rock burst risk area of the gob-side small coal pillar driving working face.

Description

Technical Field

[0001] The invention belongs to the technical field of rock burst prevention and control, and in particular relates to a method for predicting rock burst danger in an advance area along a goaf with a small coal pillar. Background Art

[0002] With the increase in mining depth and intensity, the number of mines with rock burst is also increasing rapidly, the number of accidents is increasing, and the degree of damage is also significantly aggravated. Moreover, most of the rock bursts in mines occur in the goaf-side tunnels. At the same time, the rock bursts induced during tunnel excavation are more likely to cause casualties, which has a great impact on the safe production of coal mines in my country. Therefore, the protection of the tunnels in rock burst mines is particularly important.

[0003] In the preparation stage of the working face facing the sky, after the upper section working face is mined, the side of the small coal pillar in the adjacent lower section is the roadway along the sky. The geological conditions during the roadway excavation along the sky on one side of the small coal pillar can be determined based on the roadway sketch of the adjacent upper section mining working face, and the impact hazard area affected by the geological structure during the small coal pillar along the sky can be checked in advance. However, in areas other than the geological structure, the impact hazard of the advance area to be excavated along the sky roadway cannot be determined by checking the geological structure. This makes the impact hazard of the advance area to be excavated along the sky in the process of small coal pillar roadway along the sky in a blank area, and the impact hazard of the area to be excavated cannot be judged in advance. If the roadway along the sky passes through the stress concentration area during excavation, the risk of roadway impact is greatly increased. In the face of sudden roadway impact, prevention and control measures cannot be taken in time, which is easy to cause casualties and economic losses. Therefore, how to provide a method that can not only check the advance area to be excavated along the goaf roadway to determine the impact risk of the advance area to be excavated, but also predict the impact hazard of the advance area to be excavated during the excavation of the goaf roadway, thereby improving the safety during the excavation of the goaf roadway with small coal pillars, is one of the important research directions in the industry. Summary of the invention

[0004] The purpose of the present invention is to provide a method for predicting the impact hazard of the advance area of ​​the small coal pillar along the goaf roadway, which has the characteristics of realizing advanced detection of the dangerous area of ​​the goaf roadway to improve the safety during the goaf roadway excavation of small coal pillars.

[0005] The technical solution adopted by the present invention is a method for predicting the impact hazard of the leading area of ​​small coal pillar roadway driving along the goaf, comprising the following steps:

[0006] Step 1: Collect microseismic data of the mining face of the mine, where the mining face is divided into an upper section mining face and a lower section excavation face;

[0007] Step 2: Calculate the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face according to the microseismic data, and draw a curve graph of the energy superposition value of the microseismic strike direction of the upper section mining face and a curve graph of the energy superposition value of the microseismic strike direction of the lower section excavation face;

[0008] Step 3: perform correlation analysis on the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face, draw a comparison curve of the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face, and mark the negative correlation area;

[0009] Step 4: Use the negative correlation area to predict the impact risk of the area to be excavated in the lower section.

[0010] The present invention is also characterized in that:

[0011] The microseismic data in step 1 include: occurrence time, occurrence location, distance from the coal seam, and energy value;

[0012] Step 2 is implemented as follows:

[0013] Step 201, counting microseismic data of microseismic events in the direction of the upper section mining face according to the mining footage of the upper section mining face every 10m as an interval;

[0014] Step 202: The energy values ​​of all microseismic events in the first interval of the upper section mining face are superimposed and summed according to the formula i=1,2……n for calculation;

[0015] Step 203, repeat step 202 to calculate the energy values ​​of all microseismic events in the second interval ... the Mth interval of the upper section mining face, and superimpose and sum them to obtain the energy superposition value W of the microseismic strike direction of the upper section mining face hE =(W h1 ......W hm );

[0016] Step 204: Based on the energy superposition value W of the microseismic strike direction of the upper section mining face obtained in step 203 hE =(W h1 ......W hm ), with the horizontal axis being the advancing distance of the upper section mining face, and the vertical axis being the energy superposition value in the direction of the microseismic strike of the upper section mining face, a curve of the energy superposition value in the direction of the microseismic strike of the upper section mining face is drawn;

[0017] Step 205: According to the method in step 201, the energy superposition value of the microseismic strike direction of the lower section excavation working face is counted according to the microseismic data of the microseismic events in the strike direction of the lower section excavation working face in intervals of every 10 m of excavation footage;

[0018] Step 206: The energy values ​​of all microseismic events in the first 10m interval of the lower section excavation working face are superimposed and summed according to the formula j=1,2……n calculation;

[0019] Step 207: Repeat step 206 to calculate the energy values ​​of all microseismic events in the second interval ... the Tth interval of the excavation working face of the lower section, and add them up to obtain the energy superposition value W of the microseismic strike direction of the excavation working face of the lower section. xE =(W x1 ......W xt );

[0020] Step 208: Based on the energy superposition value W of the microseismic strike direction of the lower section excavation working face obtained in step 207 xE =(W x1 ......W xt ), the excavation distance in the strike direction of the excavation working face in the lower section is the horizontal coordinate, the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is the vertical coordinate, and a curve of the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is drawn.

[0021] Step 3 is implemented as follows:

[0022] Step 301: Use the fixed working face method to add the energy superposition value W of the microseismic strike direction of the upper section mining working face hE =(W h1 ......W hm ) and the energy superposition value W of the microseismic strike direction of the lower section excavation working face xE =(W x1 ......W xt ) Taking the direction from the cutting eye to the stop-mining line of the working face as the reference, the advancement distance as the horizontal coordinate, and the microseismic energy superposition value as the vertical coordinate, a comparison curve of the energy superposition value of the microseismic strike direction of the upper section mining working face and the energy superposition value of the microseismic strike direction of the lower section excavation working face is drawn;

[0023] Step 302, analyze the comparison curve graph in step 301, mark the negative correlation area between the energy superposition value in the direction of the microseismic strike of the upper section mining face and the energy superposition value in the direction of the microseismic strike of the lower section excavation face, and clarify the negative correlation between the upper section mining face and the lower section excavation face.

[0024] Step 4 is implemented according to the following steps:

[0025] Step 401, using the negative correlation between the upper section mining face and the lower section excavation face, and screening out the excavated area of ​​the lower section, select the area to be excavated in the lower section;

[0026] Step 402: According to the negative correlation between the energy superposition values ​​of the microseismic strike direction of the upper section mining face and the lower section excavation face in the same area, the impact risk of the lower section to be excavated area is predicted according to the energy superposition value of the microseismic strike direction of the upper section mining face at the same position; the impact risk prediction in step 402 is specifically as follows: using the negative correlation between the energy superposition values ​​of the microseismic strike direction of the upper section mining face and the lower section excavation face, the energy superposition value of the microseismic strike direction of the upper section mining face is greater than 1×10 4 J, the impact risk during excavation in the lower section to be excavated at the same location is low, and the energy superposition value of the microseismic strike direction of the upper section mining face is no more than 1×10 4 J, the impact risk during excavation of the lower section to be excavated area at the same location is higher.

[0027] Step 403: When excavating to the lower section to be excavated where the impact risk is higher in the risk prediction, take decompression and danger relief measures in advance according to the on-site conditions.

[0028] The beneficial effects of the present invention are:

[0029] The method for predicting impact hazards in the advance area of ​​small coal pillar roadway excavation along the goaf of the present invention can not only investigate the advance area to be excavated along the goaf roadway to determine the impact risk of the advance area to be excavated, but also predict the impact hazard of the area to be excavated during the roadway excavation along the goaf of the small coal pillar, thereby improving the safety during the roadway excavation along the goaf of the small coal pillar; it can also take preventive measures in time in the face of sudden roadway impact situations when the impact hazard area is passed during roadway excavation, thereby reducing casualties and economic losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of the method for predicting the impact hazard of the advance area of ​​small coal pillar roadway driving along the goaf according to the present invention;

[0031] Figure 2 It is a curve diagram of energy superposition value in the direction of microseismic strike of the upper section mining working face of the method for predicting impact danger in the advance area of ​​small coal pillar roadway driving along the goaf of the present invention;

[0032] Figure 3 It is a curve diagram of energy superposition value in the direction of microseismic strike during the excavation of the lower section excavation working face of the method for predicting impact danger in the advance area of ​​small coal pillar roadway along goaf of the present invention;

[0033] Figure 4It is a comparison curve diagram of the energy superposition values ​​of the microseismic strike direction of the upper section mining face and the lower section excavation face of the method for predicting the impact hazard of the advance area of ​​the small coal pillar along the goaf roadway of the present invention;

[0034] Figure 5 It is a prediction map of impact hazard of the lower section of the area to be excavated of the method for predicting impact hazard of the advance area of ​​small coal pillar roadway excavation along the goaf of the present invention. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figure 1 As shown, the method for predicting the impact hazard of the leading area of ​​small coal pillar roadway driving along the goaf of the present invention has the following specific implementation steps:

[0037] Step 1: Collect microseismic data of the mining face of the mine. The mining face is divided into the upper section mining face and the lower section excavation face. The microseismic data include: occurrence time, occurrence location, distance from the coal seam, and energy value.

[0038] Step 2: Calculate the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face according to the microseismic data, and draw a curve graph of the energy superposition value of the microseismic strike direction of the upper section mining face and a curve graph of the energy superposition value of the microseismic strike direction of the lower section excavation face;

[0039] Step 2 is implemented as follows:

[0040] Step 201, counting the microseismic data of all microseismic events in the strike direction of the upper section mining face according to the mining footage of the upper section mining face every 10m as an interval;

[0041] Step 202: The energy values ​​of all microseismic events in the first interval of the upper section mining face are superimposed and summed according to the formula i=1,2……n for calculation;

[0042] Step 203, repeat step 202 to calculate the energy values ​​of all microseismic events in the second interval ... the Mth interval of the upper section mining face, and superimpose and sum them to obtain the energy superposition value W of the microseismic strike direction of the upper section mining face hE =(W h1 ......W hm );

[0043] Step 204: Figure 2 As shown, according to the energy superposition value W of the microseismic strike direction of the upper section mining face obtained in step 203 hE =(W h1 ......W hm), with the horizontal axis being the advancing distance of the upper section mining face, and the vertical axis being the energy superposition value in the direction of the microseismic strike of the upper section mining face, a curve of the energy superposition value in the direction of the microseismic strike of the upper section mining face is drawn;

[0044] Step 205: According to the method in step 201, the energy superposition value of the microseismic strike direction of the lower section excavation working face is counted according to the microseismic data of the microseismic events in the strike direction of the lower section excavation working face in intervals of every 10 m of excavation footage;

[0045] Step 206: The energy values ​​of all microseismic events in the first 10m interval of the lower section excavation working face are superimposed and summed according to the formula j=1,2……n calculation;

[0046] Step 207: Repeat step 206 to calculate the energy values ​​of all microseismic events in the second interval ... the Tth interval of the excavation working face of the lower section, and add them up to obtain the energy superposition value W of the microseismic strike direction of the excavation working face of the lower section. xE =(W x1 ......W xt );

[0047] Step 208: Figure 3 As shown, according to the energy superposition value W of the microseismic strike direction of the lower section excavation working face obtained in step 207 xE =(W x1 ......W xt ), the excavation distance in the strike direction of the excavation working face in the lower section is the horizontal coordinate, the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is the vertical coordinate, and a curve of the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is drawn.

[0048] Step 3: Figure 4 As shown, the correlation analysis is conducted on the energy superposition values ​​of the microseismic strike direction of the upper section mining face and the energy superposition values ​​of the microseismic strike direction of the lower section excavation face, and a comparison curve of the energy superposition values ​​of the microseismic strike direction of the upper section mining face and the energy superposition values ​​of the microseismic strike direction of the lower section excavation face is drawn, and the negative correlation area is marked;

[0049] Step 3 is implemented as follows:

[0050] Step 301: Use the fixed working face method to add the energy superposition value W of the microseismic strike direction of the upper section mining working face hE =(W h1 ......W hm ) and the energy superposition value W of the microseismic strike direction of the lower section excavation working face xE =(W x1 ......W xt) Taking the direction from the cutting eye to the stop-mining line of the working face as the reference, the advancement distance as the horizontal coordinate, and the microseismic energy superposition value as the vertical coordinate, a comparison curve of the energy superposition value of the microseismic strike direction of the upper section mining working face and the energy superposition value of the microseismic strike direction of the lower section excavation working face is drawn;

[0051] Step 302, analyze the comparison curve graph in step 301, mark the negative correlation area between the energy superposition value in the direction of the microseismic strike of the upper section mining face and the energy superposition value in the direction of the microseismic strike of the lower section excavation face, and clarify the negative correlation between the upper section mining face and the lower section excavation face.

[0052] Step 4: Figure 5 As shown, the impact risk of the area to be excavated in the lower section is predicted by using the correlation between the upper section mining face and the lower section excavation face.

[0053] Step 4 is implemented according to the following steps:

[0054] Step 401, using the negative correlation between the upper section mining face and the lower section excavation face, and screening out the excavated area of ​​the lower section, select the area to be excavated in the lower section;

[0055] Step 402: According to the negative correlation between the energy superposition values ​​of the microseismic strike direction of the upper section mining face and the lower section excavation face in the same area, the impact risk of the lower section to be excavated area is predicted according to the energy superposition value of the microseismic strike direction of the upper section mining face at the same position; the impact risk prediction in step 402 is specifically as follows: using the negative correlation between the energy superposition values ​​of the microseismic strike direction of the upper section mining face and the lower section excavation face, the energy superposition value of the microseismic strike direction of the upper section mining face is greater than 1×10 4 J, the impact risk during excavation in the lower section to be excavated at the same location is low, and the energy superposition value of the microseismic strike direction of the upper section mining face is no more than 1×10 4 J, the impact risk during excavation of the lower section to be excavated area at the same location is higher.

[0056] Step 403: When excavating to the lower section to be excavated where the impact risk is higher in the risk prediction, take decompression and danger relief measures in advance according to the on-site conditions.

[0057] Example 1

[0058] The specific implementation steps of the method for predicting the impact hazard of the leading area of ​​small coal pillar roadway driving along the goaf in this embodiment are as follows:

[0059] Step 1: Collect microseismic data of the mining face of the mine. The mining face is divided into the upper section mining face and the lower section excavation face. The microseismic data include: occurrence time, occurrence location, distance from the coal seam, and energy value.

[0060] Step 2: Calculate the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face according to the microseismic data, and draw a curve graph of the energy superposition value of the microseismic strike direction of the upper section mining face and a curve graph of the energy superposition value of the microseismic strike direction of the lower section excavation face;

[0061] Step 2 is implemented as follows:

[0062] Step 201, counting the microseismic data of all microseismic events in the strike direction of the upper section mining face according to the mining footage of the upper section mining face every 10m as an interval;

[0063] Step 202: The energy values ​​of all microseismic events in the first interval of the upper section mining face are superimposed and summed according to the formula i=1,2……n for calculation;

[0064] Step 203, repeat step 202 to calculate the energy values ​​of all microseismic events in the second interval ... the Mth interval of the upper section mining face, and superimpose and sum them to obtain the energy superposition value W of the microseismic strike direction of the upper section mining face hE =(W h1 ......W hm );

[0065] Step 204: Based on the energy superposition value W of the microseismic strike direction of the upper section mining face obtained in step 203 hE =(W h1 ......W hm ), with the horizontal axis being the advancing distance of the upper section mining face, and the vertical axis being the energy superposition value in the direction of the microseismic strike of the upper section mining face, a curve of the energy superposition value in the direction of the microseismic strike of the upper section mining face is drawn;

[0066] Step 205: According to the method in step 201, the energy superposition value of the microseismic strike direction of the lower section excavation working face is counted according to the microseismic data of the microseismic events in the strike direction of the lower section excavation working face in intervals of every 10 m of excavation footage;

[0067] Step 206: The energy values ​​of all microseismic events in the first 10m interval of the lower section excavation working face are superimposed and summed according to the formula j=1,2……n calculation;

[0068] Step 207: Repeat step 206 to calculate the energy values ​​of all microseismic events in the second interval ... the Tth interval of the excavation working face of the lower section, and add them up to obtain the energy superposition value W of the microseismic strike direction of the excavation working face of the lower section. xE =(W x1 ......W xt );

[0069] Step 208: Based on the energy superposition value W of the microseismic strike direction of the lower section excavation working face obtained in step 207 xE =(W x1 ......W xt ), the excavation distance in the strike direction of the excavation working face in the lower section is the horizontal coordinate, the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is the vertical coordinate, and a curve of the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is drawn.

[0070] Step 3: perform correlation analysis on the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face, draw a comparison curve of the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face, and mark the negative correlation area;

[0071] Step 4: Use the correlation between the upper section mining face and the lower section excavation face to predict the impact risk of the lower section's to-be-excavated area.

[0072] Example 2

[0073] The specific implementation steps of the method for predicting the impact hazard of the leading area of ​​small coal pillar roadway driving along the goaf in this embodiment are as follows:

[0074] Step 1: Collect microseismic data of the mining face of the mine. The mining face is divided into the upper section mining face and the lower section excavation face. The microseismic data include: occurrence time, occurrence location, distance from the coal seam, and energy value.

[0075] Step 2: Calculate the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face according to the microseismic data, and draw a curve graph of the energy superposition value of the microseismic strike direction of the upper section mining face and a curve graph of the energy superposition value of the microseismic strike direction of the lower section excavation face;

[0076] Step 2 is implemented as follows:

[0077] Step 201, counting the microseismic data of all microseismic events in the strike direction of the upper section mining face according to the mining footage of the upper section mining face every 10m as an interval;

[0078] Step 202: The energy values ​​of all microseismic events in the first interval of the upper section mining face are superimposed and summed according to the formula i=1,2……n for calculation;

[0079] Step 203, repeat step 202 to calculate the energy values ​​of all microseismic events in the second interval ... the Mth interval of the upper section mining face, and superimpose and sum them to obtain the energy superposition value W of the microseismic strike direction of the upper section mining face hE =(W h1 ......W hm );

[0080] Step 204: Based on the energy superposition value W of the microseismic strike direction of the upper section mining face obtained in step 203 hE =(W h1 ......W hm ), with the horizontal axis being the advancing distance of the upper section mining face, and the vertical axis being the energy superposition value in the direction of the microseismic strike of the upper section mining face, a curve of the energy superposition value in the direction of the microseismic strike of the upper section mining face is drawn;

[0081] Step 205: According to the method in step 201, the energy superposition value of the microseismic strike direction of the lower section excavation working face is counted according to the microseismic data of the microseismic events in the strike direction of the lower section excavation working face in intervals of every 10 m of excavation footage;

[0082] Step 206: The energy values ​​of all microseismic events in the first 10m interval of the lower section excavation working face are superimposed and summed according to the formula j=1,2……n calculation;

[0083] Step 207: Repeat step 206 to calculate the energy values ​​of all microseismic events in the second interval ... the Tth interval of the excavation working face of the lower section, and add them up to obtain the energy superposition value W of the microseismic strike direction of the excavation working face of the lower section. xE =(W x1 ......W xt );

[0084] Step 208: Based on the energy superposition value W of the microseismic strike direction of the lower section excavation working face obtained in step 207 xE =(W x1 ......W xt ), the excavation distance in the strike direction of the excavation working face in the lower section is the horizontal coordinate, the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is the vertical coordinate, and a curve of the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is drawn.

[0085] Step 3: perform correlation analysis on the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face, draw a comparison curve of the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face, and mark the negative correlation area;

[0086] Among them, the correlation analysis can calculate the lateral cantilever length of the upper section mining face according to the theoretical calculation using the cantilever beam length formula on the air side, and judge the correlation between the cantilever length and the elastic energy release according to the cantilever beam bending deformation formula. Specifically, the lateral cantilever length of the upper section mining face is calculated according to the cantilever beam length formula on the air side. The cantilever beam length formula on the air side is:

[0087]

[0088] In formula (1), q is the uniform load of the overlying rock layer, h is the thickness of the low-lying key layer, and R T is the ultimate tensile strength, L is the length of the lateral cantilever beam of the upper section mining face;

[0089] According to the comprehensive drilling geological parameters of the mine recovery working face, h = 10m, R T =4.5MPa, q=174.7kPa, the cantilever length of the low-level key layer is calculated to be 29.3m. When the length of the cantilever beam on the air side exceeds this limit value, the cantilever beam breaks and becomes unstable. The correlation between the cantilever length and the release of elastic energy is determined according to the bending deformation formula of the cantilever beam on the air side. The energy accumulated during the bending process of the cantilever beam on the air side is:

[0090]

[0091] In formula (2), q is the uniform load of the overburden; h is the thickness of the low-lying key layer; E is the elastic modulus; L is the length of the cantilever beam;

[0092] The larger the cantilever beam on the air side, the greater the accumulated elastic energy. During the excavation of the adjacent small coal pillars along the air, the cantilever beam is prone to breakage and instability due to secondary disturbance, and the greater the energy released during the excavation of the small coal pillars along the air; the larger the cantilever beam on the air side, the smaller the energy released during the mining of the upper section mining face, and the greater the accumulated energy. According to the length of the cantilever beam on the air side and the bending deformation formula, the correlation analysis was performed on the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face.

[0093] Step 3 is implemented as follows:

[0094] Step 301: Use the fixed working face method to add the energy superposition value W of the microseismic strike direction of the upper section mining working face hE =(W h1 ......W hm ) and the energy superposition value W of the microseismic strike direction of the lower section excavation working face xE =(W x1 ......W xt) Taking the direction from the cutting eye to the stop-mining line of the working face as the reference, the advancement distance as the horizontal coordinate, and the microseismic energy superposition value as the vertical coordinate, a comparison curve of the energy superposition value of the microseismic strike direction of the upper section mining working face and the energy superposition value of the microseismic strike direction of the lower section excavation working face is drawn;

[0095] Step 302, analyze the comparison curve graph in step 301, mark the negative correlation area between the energy superposition value in the direction of the microseismic strike of the upper section mining face and the energy superposition value in the direction of the microseismic strike of the lower section excavation face, and clarify the negative correlation between the upper section mining face and the lower section excavation face.

[0096] Step 4: Use the correlation between the upper section mining face and the lower section excavation face to predict the impact risk of the lower section's to-be-excavated area.

[0097] Example 3

[0098] The specific implementation steps of the method for predicting the impact hazard of the leading area of ​​small coal pillar roadway driving along the goaf in this embodiment are as follows:

[0099] Step 1: Collect microseismic data of the mining face of the mine. The mining face is divided into the upper section mining face and the lower section excavation face. The microseismic data include: occurrence time, occurrence location, distance from the coal seam, and energy value.

[0100] Step 2: Calculate the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face according to the microseismic data, and draw a curve graph of the energy superposition value of the microseismic strike direction of the upper section mining face and a curve graph of the energy superposition value of the microseismic strike direction of the lower section excavation face;

[0101] Step 2 is implemented as follows:

[0102] Step 201, counting the microseismic data of all microseismic events in the strike direction of the upper section mining face according to the mining footage of the upper section mining face every 10m as an interval;

[0103] Step 202: The energy values ​​of all microseismic events in the first interval of the upper section mining face are superimposed and summed according to the formula i=1,2……n for calculation;

[0104] Step 203, repeat step 202 to calculate the energy values ​​of all microseismic events in the second interval ... the Mth interval of the upper section mining face, and superimpose and sum them to obtain the energy superposition value W of the microseismic strike direction of the upper section mining face hE =(W h1 ......W hm );

[0105] Step 204: Figure 2 As shown, according to the energy superposition value W of the microseismic strike direction of the upper section mining face obtained in step 203 hE =(W h1 ......W hm ), with the horizontal axis being the advancing distance of the upper section mining face, and the vertical axis being the energy superposition value in the direction of the microseismic strike of the upper section mining face, a curve of the energy superposition value in the direction of the microseismic strike of the upper section mining face is drawn;

[0106] Step 205: According to the method in step 201, the energy superposition value of the microseismic strike direction of the lower section excavation working face is counted according to the microseismic data of the microseismic events in the strike direction of the lower section excavation working face in intervals of every 10 m of excavation footage;

[0107] Step 206: The energy values ​​of all microseismic events in the first 10m interval of the lower section excavation working face are superimposed and summed according to the formula j=1,2……n calculation;

[0108] Step 207: Repeat step 206 to calculate the energy values ​​of all microseismic events in the second interval ... the Tth interval of the excavation working face of the lower section, and add them up to obtain the energy superposition value W of the microseismic strike direction of the excavation working face of the lower section. xE =(W x1 ......W xt );

[0109] Step 208: Figure 3 As shown, according to the energy superposition value W of the microseismic strike direction of the lower section excavation working face obtained in step 207 xE =(W x1 ......W xt ), the excavation distance in the strike direction of the excavation working face in the lower section is the horizontal coordinate, the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is the vertical coordinate, and a curve of the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is drawn.

[0110] Step 3: perform correlation analysis on the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face, draw a comparison curve of the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face, and mark the negative correlation area;

[0111] Step 3 is implemented as follows:

[0112] Step 301: Use the fixed working face method to add the energy superposition value W of the microseismic strike direction of the upper section mining working face hE =(W h1 ......W hm) and the energy superposition value W of the microseismic strike direction of the lower section excavation working face xE =(W x1 ......W xt ) Taking the direction from the cutting eye to the stop-mining line of the working face as the reference, the advancement distance as the horizontal coordinate, and the microseismic energy superposition value as the vertical coordinate, a comparison curve of the energy superposition value of the microseismic strike direction of the upper section mining working face and the energy superposition value of the microseismic strike direction of the lower section excavation working face is drawn;

[0113] Step 302, analyze the comparison curve graph in step 301, mark the negative correlation area between the energy superposition value in the direction of the microseismic strike of the upper section mining face and the energy superposition value in the direction of the microseismic strike of the lower section excavation face, and clarify the negative correlation between the upper section mining face and the lower section excavation face.

[0114] Step 4: Figure 5 As shown, the impact risk of the area to be excavated in the lower section is predicted by using the correlation between the upper section mining face and the lower section excavation face.

[0115] Step 4 is implemented according to the following steps:

[0116] Step 401, using the negative correlation between the upper section mining face and the lower section excavation face, and screening out the excavated area of ​​the lower section, select the area to be excavated in the lower section;

[0117] Step 402: According to the negative correlation between the energy superposition values ​​of the microseismic strike direction of the upper section mining face and the lower section excavation face in the same area, the impact risk of the lower section to be excavated area is predicted according to the energy superposition value of the microseismic strike direction of the upper section mining face at the same position; the impact risk prediction in step 402 is specifically as follows: using the negative correlation between the energy superposition values ​​of the microseismic strike direction of the upper section mining face and the lower section excavation face, the energy superposition value of the microseismic strike direction of the upper section mining face is greater than 1×10 4 J, the impact risk during excavation in the lower section to be excavated at the same location is low, and the energy superposition value of the microseismic strike direction of the upper section mining face is no more than 1×10 4 J, the impact risk during excavation of the lower section to be excavated area at the same location is higher.

[0118] Step 403: When excavating to the lower section to be excavated where the impact risk is higher in the risk prediction, take decompression and danger relief measures in advance according to the on-site conditions.

Claims

1. A method for predicting the impact hazard of the leading area of ​​a small coal pillar along the goaf, characterized in that: The following steps are involved: Step 1: Collect microseismic data of the mining face of the mine, where the mining face is divided into an upper section mining face and a lower section excavation face; Step 2, respectively calculating the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face according to the microseismic data, and drawing a curve graph of the energy superposition value of the microseismic strike direction of the upper section mining face and a curve graph of the energy superposition value of the microseismic strike direction of the lower section excavation face; Step 3, performing correlation analysis on the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face, drawing a comparison curve of the energy superposition value of the microseismic strike direction of the upper section mining face and the energy superposition value of the microseismic strike direction of the lower section excavation face, and marking the negative correlation area; Step 4: Use the negative correlation area to predict the impact risk of the area to be excavated in the lower section.

2. The method for predicting the impact hazard of the leading area of ​​small coal pillar roadway driving along the goaf according to claim 1 is characterized in that: The microseismic data in step 1 include: occurrence time, occurrence location, distance from the coal seam, and energy value.

3. The method for predicting the impact hazard of the leading area of ​​small coal pillar roadway driving along the goaf according to claim 2 is characterized in that: The step 2 is specifically implemented as follows: Step 201, counting microseismic data of microseismic events in the direction of the upper section mining face according to the mining footage of the upper section mining face every 10m as an interval; Step 202: According to the formula Calculating the energy values ​​of all microseismic events in the first interval of the upper section mining face; Step 203, repeat step 202 to calculate the energy values ​​of all microseismic events in the second interval ... the Mth interval of the upper section mining face, and obtain the energy superposition value W of the microseismic strike direction of the upper section mining face hE =(W h1 ......W hm ); Step 204: The energy superposition value W of the microseismic strike direction of the upper section mining face according to step 203 hE =(W h1 ......W hm ), with the horizontal axis being the advancing distance of the upper section mining face, and the vertical axis being the energy superposition value in the direction of the microseismic strike of the upper section mining face, a curve of the energy superposition value in the direction of the microseismic strike of the upper section mining face is drawn; Step 205: According to the method in step 201, the energy superposition value of the microseismic strike direction of the lower section excavation working face is counted according to the microseismic data of the microseismic events in the strike direction of the lower section excavation working face in intervals of every 10 m of excavation footage; Step 206: According to the formula Calculate the energy values ​​of all microseismic events within the first 10m interval of the excavation working face of the lower section; Step 207: Repeat step 206 to calculate the energy values ​​of all microseismic events in the second interval ... the Tth interval of the excavation working face of the lower section, and obtain the energy superposition value W of the microseismic strike direction of the excavation working face of the lower section. xE =(W x1 ......W xt ); Step 208: The energy superposition value W of the microseismic strike direction of the lower section excavation working face according to step 207 xE =(W x1 ......W xt ), the excavation distance in the strike direction of the excavation working face in the lower section is the horizontal coordinate, the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is the vertical coordinate, and a curve of the energy superposition value in the strike direction of the microseismic excavation working face in the lower section is drawn.

4. The method for predicting the impact hazard of the leading area of ​​small coal pillar roadway driving along the goaf according to claim 3 is characterized in that: The step 3 is specifically implemented according to the following steps: Step 301: Use the fixed working face method to add the energy superposition value W of the microseismic strike direction of the upper section mining working face hE =(W h1 ......W hm ) and the energy superposition value W of the microseismic strike direction of the lower section excavation working face xE =(W x1 ......W xt ) Taking the direction from the cutting eye to the stop-mining line of the working face as the reference, the advancement distance as the horizontal coordinate, and the microseismic energy superposition value as the vertical coordinate, a comparison curve of the energy superposition value of the microseismic strike direction of the upper section mining working face and the energy superposition value of the microseismic strike direction of the lower section excavation working face is drawn; Step 302, analyze the comparison curve graph described in step 301, mark the negative correlation area between the energy superposition value in the direction of microseismic strike of the upper section mining face and the energy superposition value in the direction of microseismic strike of the lower section excavation face, and clarify the negative correlation between the upper section mining face and the lower section excavation face.

5. The method for predicting the impact hazard of the leading area of ​​small coal pillar driving along the goaf according to claim 4 is characterized in that: The step 4 is specifically implemented according to the following steps: Step 401, using the negatively correlated area, screen out the excavated area of ​​the lower section, and select the area to be excavated in the lower section; Step 402: According to the negative correlation between the energy superposition values ​​of the microseismic strike direction of the upper section mining face and the lower section excavation face in the same area, the impact risk of the lower section to be excavated area is predicted based on the energy superposition value of the microseismic strike direction of the upper section mining face at the same position; Step 403: When excavating to the lower section to be excavated where the impact risk is higher in the risk prediction, take decompression and danger relief measures in advance according to the excavation situation.

6. The method for predicting the impact hazard of the leading area of ​​small coal pillar driving along the goaf according to claim 5 is characterized in that: The impact risk prediction in step 402 is specifically as follows: using the negative correlation between the energy superposition values ​​of the microseismic strike direction of the upper section mining face and the lower section excavation face, the energy superposition value of the microseismic strike direction of the upper section mining face is greater than 1×10 4 J, the impact risk during excavation in the lower section to be excavated at the same location is low, and the energy superposition value of the microseismic strike direction of the upper section mining face is no more than 1×10 4 J, the impact risk during excavation of the lower section to be excavated area at the same location is higher.

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