Roof-cutting gob-side entry retaining operation method

Abstract

The invention provides a top-cutting gob-side entry retaining operation method, and relates to the field of coal mine operation. The method comprises the following steps: preliminarily formulating a construction process; carrying out risk grade division on risk factors of key posts involved in the construction process; according to the divided risk levels, optimizing protection measures in the construction process until the risk levels are reduced to a preset level or below the preset level; and roof cutting gob-side entry retaining operation is carried out according to the optimized construction process. According to the method, after a construction process is formulated, risk grade division is carried out on risks of risk factors of key posts, protection measures are increased or improved according to the divided risk grades, namely, the protection measures are optimized, and after the risks of the risk factors of the key posts are all reduced to a preset grade or below the preset grade, the protection measures are optimized. According to the method, the operation is carried out according to the optimized construction process, the operation safety can be greatly improved, and as quantitative optimization is adopted in the optimization process, the protection measures are more accurate, and the safety of the construction process can be further guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal mine operation, in particular to a top-cutting gob-side entry retaining operation method. BACKGROUND

[0002] The top-cutting gob-side entry retaining can improve the coal recovery rate of the working face and relieve the tension of the mining and excavation replacement of the mine. In the specific construction, as shown in Figure 1 , and in combination with Figure 2 , before the recovery of the upper section working face 1, a row of reinforced anchor cables 6 is arranged on the goaf side of the upper section return airway 2, and the directional top breaking hole 4 is constructed on the roof of the return airway 2 on the side of the roof, and after a certain distance behind the reinforced anchor cable 6, the directional top breaking hole 4 is detonated or hydraulically fractured to break the top; after the recovery of the upper section working face 1, the artificial roadway side 10 composed of I-steel and steel mesh is installed on the goaf side to support the gangue; considering the influence of the working face recovery disturbance and the mine pressure during the recovery of the working face, dense point columns 9 are also arranged to prevent the roof rock of the entry retaining section from being unstable, and after a certain distance behind the working face, the surrounding rock of the entry retaining section tends to be stable, so that the unit frame can be removed and only the artificial roadway side composed of I-steel and steel mesh is retained.

[0003] It can be seen that the top-cutting gob-side entry retaining operation involves supporting, top cutting, blasting and other work contents, and each work content faces many dangerous factors, so the operation is relatively dangerous. However, the recognition of the danger of each work content in the prior art is still insufficient, which leads to the easy occurrence of accidents. SUMMARY

[0004] The present application aims to provide a top-cutting gob-side entry retaining operation method to solve the technical problem that the top-cutting gob-side entry retaining operation in the prior art is still prone to accidents.

[0005] The top-cutting gob-side entry retaining operation method provided by the present application comprises:

[0006] initially establishing a construction process;

[0007] dividing the dangerous factors of the key positions involved in the construction process into risk levels;

[0008] optimizing the protective measures in the construction process according to the divided risk levels until the risk level is reduced to a preset level or below;

[0009] carrying out the top-cutting gob-side entry retaining operation according to the optimized construction process.

[0010] Further, the step of dividing the dangerous factors of the key positions involved in the construction process into risk levels comprises:

[0011] Key post division: according to the preliminary formulated construction process, the key post of the top cutting along empty roadway is divided;

[0012] Risk identification: identify the dangerous factors and possible accidents or incidents of the work of each key post;

[0013] Risk value calculation: calculate the risk value R of each dangerous factor leading to an accident by R=LXS, wherein L is the possibility of each dangerous factor leading to an accident, and S is the consequence severity of the accident caused by each dangerous factor;

[0014] Risk value optimization: according to the confidence of unascertained rational number, the calculated risk value R is optimized;

[0015] Risk level division: according to the optimized risk value of each risk, the risk level of each dangerous factor leading to an accident is divided.

[0016] Further, in the key post division, the top cutting along empty roadway operation is divided into the following key posts: reinforcement anchor cable drilling machine operator post, reinforcement anchor cable support worker post, directional top breaking hole drilling worker post, blasting worker post, single support worker post.

[0017] Further, when identifying the dangerous factors of the work of the key post, the work hazard analysis method is adopted.

[0018] Further, when calculating the risk value R, according to whether the operation environment is good, whether the equipment and facilities are intact, whether the prevention measures are in place, whether the personnel safety consciousness is strong or weak, and whether the operation procedures are complete, the possibility L of each dangerous factor leading to an accident is valued, each aspect accounts for 1 point, a total of 5 points, the higher the score, the greater the possibility L of the corresponding dangerous factor leading to an accident.

[0019] Further, when calculating the risk value R, according to whether it causes personnel casualties, whether it causes equipment damage, and whether it leads to shutdown or production stoppage, the consequence severity S of the accident caused by each dangerous factor is valued, and according to the severity of the consequences, 1 to 6 points are assigned, the higher the score, the more serious the accident consequences.

[0020] Further, when calculating the risk value R, at least five experts in the relevant field score the possibility L of each dangerous factor leading to an accident and the consequence severity S of the accident, and calculate a plurality of risk values R according to the expert scoring.

[0021] Further, when optimizing the risk value R, first, in the initial confidence interval, the credibility of the risk value R of each dangerous factor of each key post given by different scorers is determined, then the optimization confidence interval is determined according to the credibility, and the average value of the risk value R in the optimization confidence interval is taken as the optimized risk value. Further, in the key post division, the top cutting along empty roadway operation is divided into the following key posts: reinforcement anchor cable drilling machine operator post, reinforcement anchor cable support worker post, directional top breaking hole drilling worker post, blasting worker post, single support worker post.

[0017] Further, when identifying the dangerous factors of the work of the key post, the work hazard analysis method is adopted.

[0018] Further, when calculating the risk value R, according to whether the operation environment is good, whether the equipment and facilities are intact, whether the prevention measures are in place, whether the personnel safety consciousness is strong or weak, and whether the operation procedures are complete, the possibility L of each dangerous factor leading to an accident is valued, each aspect accounts for 1 point, a total of 5 points, the higher the score, the greater the possibility L of the corresponding dangerous factor leading to an accident.

[0019] Further, when calculating the risk value R, according to whether it causes personnel casualties, whether it causes equipment damage, and whether it leads to shutdown or production stoppage, the consequence severity S of the accident caused by each dangerous factor is valued, and according to the severity of the consequences, 1 to 6 points are assigned, the higher the score, the more serious the accident consequences.

[0020] Further, when calculating the risk value R, at least five experts in the relevant field score the possibility L of each dangerous factor leading to an accident and the consequence severity S of the accident, and calculate a plurality of risk values R according to the expert scoring.

[0021] Further, when optimizing the risk value R, first, in the initial confidence interval, the credibility of the risk value R of each dangerous factor of each key post given by different scorers is determined, then the optimization confidence interval is determined according to the credibility, and the average value of the risk value R in the optimization confidence interval is taken as the optimized risk value.

[0022] Further, according to the optimized risk degree value, the risk levels are divided into low risk, general risk, greater risk and major risk, the risk degree value of the low risk ranges from 1 to 3, the risk degree value of the general risk ranges from 4 to 8, the risk degree value of the greater risk ranges from 9 to 16, and the risk degree value of the major risk ranges from 18 to 30.

[0023] Further, the method further comprises: drawing a safety risk comparison chart of the top-cut along empty roadway operation according to the risk levels.

[0024] Further, the safety risk comparison chart comprises at least one of a column chart and a pie chart.

[0025] The top-cut along empty roadway operation method provided by the application can produce the following beneficial effects:

[0026] The top-cut along empty roadway operation method provided by the application, after the construction process is formulated, does not directly perform the top-cut along empty roadway operation according to the construction process immediately, but optimizes the construction process, specifically, after the construction process is initially formulated, the danger of the dangerous factors of the key positions is quantitatively divided, that is, the risk levels are divided, and the protection measures are increased or improved according to the divided risk levels, that is, the protection measures are optimized, and after the danger of the dangerous factors of the key positions is reduced to the preset level or below, the operation is performed according to the optimized construction process, thus, the safety of the operation can be greatly improved, and since the optimization process adopts quantitative optimization, the protection measures are more accurate, and the safety of the construction process can be further ensured. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only the embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of the provided drawings.

[0028] Figure 1 It is a top-cut along empty roadway operation construction process schematic diagram in the prior art;

[0029] Figure 2 It is a top-cut along empty roadway operation construction process control chart in the prior art;

[0030] Figure 3 It is a flowchart of the top-cut along empty roadway operation method provided by the embodiment of the application;

[0031] Figure 4 It is a flowchart of the risk level division in the top-cut along empty roadway operation method provided by the embodiment of the application;

[0032] Figure 5 A risk level columnar graph obtained in the top cutting and gob-side entry retaining operation method provided by the embodiment of the present application is shown in the figure;

[0033] Figure 6 A risk level pie chart obtained in the top cutting and gob-side entry retaining operation method provided by the embodiment of the present application is shown in the figure.

[0034] Explanation of reference signs:

[0035] 1 - upper section working face; 2 - upper section air return roadway; 3 - lower section working face; 4 - directional top breaking hole; 5 - upper section transportation roadway; 6 - reinforced anchor cable; 7 - basic roof rock; 8 - immediate roof rock; 9 - dense point column; 10 - artificial roadway side formed by I-beam and metal mesh. DETAILED DESCRIPTION

[0036] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0037] The embodiment provides a top cutting and gob-side entry retaining operation method, as shown in the figure, the method comprises the following steps: Figure 3

[0038] S310, initially form a construction process;

[0039] S320, divide the risk levels of the dangerous factors involved in the key positions in the construction process;

[0040] S330, optimize the protection measures in the construction process according to the divided risk levels, until the risk levels are reduced to a preset level or below;

[0041] S340, perform the top cutting and gob-side entry retaining operation according to the optimized construction process.

[0042] The top cutting and gob-side entry retaining operation safety evaluation method provided by the embodiment does not directly perform the top cutting and gob-side entry retaining operation immediately according to the construction process after the construction process is formed, but optimizes the construction process. Specifically, after the construction process is initially formed, the dangerousness of the dangerous factors of the key positions is quantitatively divided, that is, the risk levels are divided, and the protection measures are increased or improved according to the divided risk levels, that is, the protection measures are optimized, and after the dangerousness of the dangerous factors of each key position is reduced to a preset level or below, the operation is performed according to the optimized construction process. In this way, the safety of the operation can be greatly improved, and since the optimization process adopts quantitative optimization, the protection measures are more accurate, which can further ensure the safety of the construction process. ​

[0043] Specifically, in the embodiment, as shown in the step of classifying the risk levels of the dangerous factors involved in the key positions in the construction process, includes: Figure 4

[0044] S410, key position classification: according to the preliminarily formulated construction process, the key position classification of the top cutting along the empty roadway operation is performed.

[0045] Specifically, in the embodiment, in the key position classification, the top cutting along the empty roadway operation is divided into the following key positions: reinforcement anchor cable drill operator position, reinforcement anchor cable support worker position, directional top breaking hole drilling worker position, blasting worker position, single support worker position.

[0046] S420, risk identification: identify the dangerous factors and possible accidents or incidents of the work of each key position.

[0047] S430, risk value calculation: using the risk matrix method, that is, using R=LxS to calculate the risk value R or the risk value R of the accident caused by each dangerous factor. The larger the R value, the higher the risk degree or the greater the risk of the dangerous factor. Wherein, L is the possibility of the accident caused by each dangerous factor. The larger the L value, the greater the possibility of the accident caused by the dangerous factor. S is the consequence severity of the accident caused by each dangerous factor. The larger the S value, the more serious the consequences of the accident caused by the dangerous factor. The risk matrix method combines qualitative analysis and quantitative analysis, and fully considers the risk influence and risk probability factors.

[0048] S440, risk value optimization: according to the confidence of unascertained rational number, the calculated risk value R is optimized. In this way, the deviation caused by subjective factor cognitive difference can be effectively reduced, and the accuracy of the evaluation can be ensured.

[0049] S450, risk level classification: according to the optimized risk value of each risk, the risk level of the accident caused by each dangerous factor is classified.

[0050] The top cutting along the empty roadway operation method provided by the embodiment, when classifying the risk level, the key position classification of the top cutting along the empty roadway operation is performed, the dangerous factors and possible accidents or incidents of the work of the key position are identified, the dangers faced by the key position of the top cutting along the empty roadway operation and the possible accidents or incidents can be comprehensively and qualitatively mastered; on this basis, the embodiment also calculates the risk value of the accident caused by the dangerous factor using the risk matrix method, that is, the risk of each dangerous factor is quantitatively analyzed to improve the objective accuracy of the evaluation; moreover, the risk value is optimized using the confidence concept of unascertained rational number, thereby further ensuring the rationality and accuracy of the evaluation. Therefore, using the method provided by the embodiment is very beneficial to the safe performance of the top cutting along the empty roadway operation.​

[0051] Specifically, in this embodiment, when the risk factors of the key post work are identified, i.e. risk identification, the work hazard analysis method is adopted, and the specific identification results are shown in Table 1 (including Tables 1.1-1.5).

[0052] Table 1.1 Identification of work risk factors of reinforcing anchor cable drill operator post

[0053]

[0054] Table 1.2 Identification of work risk factors of reinforcing anchor cable support worker post

[0055]

[0056] Table 1.3 Identification of work risk factors of directional hole drilling worker post

[0057]

[0058] Table 1.4 Identification of work risk factors of blasting worker post

[0059]

[0060] Table 1.5 Identification of work risk factors of single support worker post

[0061]

[0062] In this embodiment, when calculating the risk degree value R, the possibility L of each risk factor leading to an accident is valued according to whether the working environment is good, whether the equipment and facilities are intact, whether the prevention measures are in place, whether the personnel safety awareness is strong, and whether the operation procedures are complete. Each aspect accounts for 1 point, a total of 5 points, and the higher the score, the greater the possibility L of the corresponding risk factor leading to an accident.

[0063] The possibility L of each risk factor leading to an accident, i.e. the possibility L of an accident occurring, is mainly affected by five aspects: working environment, equipment and facilities, prevention measures, personnel safety awareness, and operation procedures. The absence or lack of each aspect will increase the possibility of an accident, so the corresponding L value is also higher. Considering that each aspect L value is 1 point, for example: if the system working environment is poor, the equipment and facilities are faulty, the prevention measures are lacking, the personnel safety awareness is poor, and the operation procedures are not complete, the system L value is 5 points, indicating that the possibility of an accident is very large; if the system working environment is good, the equipment and facilities are intact, the prevention measures are in place, the personnel safety awareness is high, and the operation procedures are complete, the system L value is 0 points, indicating that theoretically an accident cannot occur.

[0064] The top cutting along empty roadway operation is in the production front line in the underground, the environment space is relatively small, the activity is limited, the visibility is low, and it is almost impossible to make the operation environment better, so the L value is assigned 1 point in the operation environment, and the final L value will be around the equipment, facilities, prevention measures, personnel safety awareness, and operation procedures. On the basis of L being assigned 1 point, each additional item is assigned 1 point, as shown in Table 2, which shows the L value standard reference or judgment criteria.

[0065] Table 2 L judgment criteria for accident occurrence

[0066]

[0067] Because the accident consequence severity S mainly reflects whether personnel are injured, whether equipment is damaged, and whether production is stopped or production is affected, in this embodiment, when calculating the risk degree value R, the accident consequence severity S caused by each risk factor is valued according to whether personnel are injured, whether equipment is damaged, and whether production is stopped or production is affected. According to the severity of the consequences, 1 to 6 points are assigned, and the higher the score, the more serious the accident consequences. For example, if no personnel are injured, no equipment is damaged, and no production is stopped, it means that the accident consequences are acceptable, and S is assigned 1 point. According to the severity and acceptability of the accident consequences, the value of S is gradually increased. Table 3 shows the S value standard reference or judgment criteria.

[0068] Table 3 S judgment criteria for accident consequence severity

[0069]

[0070] After obtaining the value of the accident possibility L caused by each risk factor, i.e., the possibility of accident occurrence, and the value of the accident consequence severity S, the risk degree value or danger value R caused by each risk factor can be calculated using the formula R = L x S. Table 4 shows the value range of the risk degree value or danger value R.

[0071] Table 4 Value range of risk degree value or danger value R

[0072]

[0073] Specifically, in this embodiment, at least five experts in the relevant field score the accident possibility L caused by each risk factor and the accident consequence severity S, and a plurality of risk degree values R are calculated according to the expert scores.

[0074] Invite at least five experts to form a scoring group, each scoring, which can effectively reduce the problem of large deviation caused by human subjective factor cognitive difference to some extent, make the scoring result more accurate. In addition, in order to more accurately evaluate the risk degree and risk level of various accidents, the embodiment also optimizes the R value by combining the confidence concept of unascertained rational number.

[0075] Rational number is a type of number in mathematics used to describe continuous variables in the physical world and real life, which can be used to more accurately represent unknown variables. Using rational numbers can avoid simplifying complex variables into single real numbers, thereby reducing the risk of information omission or distortion.

[0076] Let a be any real number, 0 < α ≤ 1, and call a first-order unascertained rational number, where α, and [a, b] represent the total confidence, confidence distribution density function and value interval of the unascertained rational number respectively, if

[0077]

[0078] Call n-order unascertained rational number, x i is the ith value in the value interval [a, b], α i is the confidence of x i .

[0079] Based on the above concept, in the embodiment, when optimizing the risk degree value R, first determine the confidence of the risk degree value R of each dangerous factor of each key post given by different scorers in the initial confidence interval, then determine the optimized confidence interval according to the confidence, that is, the confidence interval with higher confidence, and take the average value of the risk degree value R in the optimized confidence interval as the optimized risk degree value.

[0080] The following examples illustrate the above R value optimization method. The following table is the record of R value and optimized R value obtained by five coal experts scoring L value and S value of each dangerous factor of reinforcing anchor cable drilling machine operator post.

[0081] Table 5 R value and optimized R value of reinforcing anchor cable drilling machine operator post

[0082]

[0083] Taking the "wind pipe, water pipe, hydraulic pipe joint, and drill pipe, which produce risk leading to object impact" of the reinforcing anchor cable drilling machine operator post as an example, the calculation process is as follows:

[0084] Introducing "distribution density type" unascertained rational number, denoted as: as shown in the following formula:

[0085]

[0086] The value interval of the unascertained rational number is [9, 18], is the subjective credibility distribution density on the closed interval, then the density function It is shown that: for the risk of "wind pipe, water pipe, hydraulic pipe joint, and drill pipe, causing risk leading to object strike" of the reinforced anchor cable drilling machine operator post, the R values given by the three scoring experts are 9, 10, and 18, and the R values given by the two scoring experts are both 12. Among the five numbers, 9, 10, and 18 each appear once, and 12 appears twice. The credibility of 9, 10, and 18 is 1 / 5, and the credibility of 12 is 2 / 5. It can be seen that 18 deviates greatly in the interval [9, 18], and the credibility of R value in the interval [9, 12] is 1 / 5+1 / 5+2 / 5=4 / 5, which is relatively high. Therefore, the average value in the interval [9, 12] can better represent the true R value. Therefore, the final R value of the risk evaluation of "wind pipe, water pipe, hydraulic pipe joint, and drill pipe, causing risk leading to object strike" of the reinforced anchor cable drilling machine operator post is the average of 9, 10, and 12, i.e. the optimized R value 10.75 is taken.

[0087] In this embodiment, the optimized R value, i.e. is taken as the final evaluation index.

[0088] Specifically, in this embodiment, according to the optimized risk degree value The risk levels are divided into low risk, general risk, greater risk, and major risk. The range of risk degree value of low risk is [1, 3], the range of risk degree value of general risk is [4, 8], the range of risk degree value of greater risk is [9, 16], and the range of risk degree value of major risk is [18, 30].

[0089] Of course, low risk, general risk, greater risk, and major risk can also be referred to as IV-level risk, III-level risk, II-level risk, and I-level risk, respectively.

[0090] The following is a specific embodiment:

[0091] There is a mine with an average thickness of 2.85m in the main mining coal seam and siltstone and sandy mudstone in the roof. It is planned to adopt the technology of cutting the top and leaving the lane along the goaf to improve the coal recovery rate of the working face and alleviate the problem of tight mining and excavation replacement in the mine. Before the working face is mined, a row of reinforcing anchor cables are arranged on the goaf side of the mining roadway with a spacing of 1m and an anchor cable length of 13m. At the same time, directional blasting broken top holes are constructed on the roof of the mining side of the return air roadway. The depth of the broken top holes is 11m, the spacing is 500mm, and the angle with the vertical direction is 15°. After the reinforcing anchor cables are reinforced for 100m, the directional blasting broken top holes are charged and blasted. After the working face is mined, a row of reinforcing anchor cables are arranged on the goaf side of the frame. An artificial roadway wall composed of I-beams and steel mesh is installed. The length of the I-beam is 4.0m. To prevent the I-beam from overturning, the top of the I-beam is inserted into the roof rock layer 200mm, and the bottom is inserted into the bottom plate 300mm. The size of the steel mesh is height × width = 3.5m × 1.2m. Taking into account that during the mining period of the working face, the tunnel surrounding rock within 300m of the lagging working face is not stable due to the disturbance caused by the mining of the working face and the influence of mine pressure, it is necessary to arrange dense point columns to prevent the roof rock layer of the remaining roadway section from becoming unstable. The spacing between single pillars is 500mm. After 300m of the lagging working face, the surrounding rock of the remaining roadway section tends to be stable, and the unit frame can be removed to retain only the artificial roadway wall composed of I-beams and steel mesh.

[0092] By adopting the roof cutting and goaf-keeping operation method provided in this embodiment, the risk values ​​R of various accident types caused by various hazardous factors in the positions of reinforcement anchor drill rig operators, directional broken top hole drillers, reinforcement anchor support workers, single support workers and blasting workers in the roof cutting and goaf-keeping operation activities of the coal mine are optimized and calculated, and the risk levels are obtained, as shown in Table 6 (including Tables 6.1-6.5).

[0093] Table 6.1 Risk level and risk grade of anchor drill operator

[0094]

[0095] Table 6.2 Risk degree and risk level of reinforcement anchor support workers

[0096]

[0097] Table 6.3 Risk level and risk grade of directional top hole drilling workers

[0098]

[0099] Table 6.4 Risk degree and risk level of blasting workers

[0100]

[0101] Table 6.5 Risk degree and risk level of single support worker positions

[0102]

[0103] Based on the above analysis, the following evaluation results can be obtained:

[0104] (1) The main risk factors of the reinforced anchor cable drilling machine operator and directional top hole drilling worker post are live gangue dangerous rock, water pipe joint, hydraulic hose joint, hydraulic drill carriage walking, hydraulic drill carriage drilling, drill pipe, dust, and coal dust. The possible accident types are partial roof fall, object impact, pneumoconiosis, coal dust explosion, and vehicle injury. Among them, the partial roof fall risk level is II, which is a greater risk; the object impact risk level is II, which is a greater risk; the pneumoconiosis risk level is IV, which is a low risk; the coal dust explosion risk level is III, which is a general risk; and the vehicle injury risk level is II, which is a greater risk.

[0105] (2) The main risk factor of the reinforced anchor cable support worker post is the roof. The possible accident type is partial roof fall, and the risk level is III, which is a general risk.

[0106] (3) The main risk factors of the blasting worker post are explosive materials and toxic and harmful gases. The possible accident types are blasting injury and gunpowder smoke poisoning. Among them, the blasting injury risk level is II, which is a greater risk; and the gunpowder smoke poisoning risk level is IV, which is a low risk.

[0107] (4) The main risk factors of the single support worker post are live gangue dangerous rock, roof, free side gangue, and single prop. The possible accident types are partial roof fall, roadway collapse, and object impact. Among them, the partial roof fall risk level is II, which is a greater risk; the roadway collapse risk level is I, which is a major risk; and the object impact risk level is III, which is a general risk.

[0108] After obtaining the optimized risk degree value and the corresponding risk level, the method provided in this embodiment further includes: S460, drawing a roof cutting along empty roadway operation safety risk comparison chart according to the risk level, and the safety risk comparison chart includes at least one of a column chart and a pie chart.

[0109] As shown in Figure 5 and Figure 6 , in the safety risk comparison chart, the risk level can be more intuitively represented by color, for example, blue represents low risk, yellow represents general risk, orange represents greater risk, and red represents major risk.

[0110] More specifically, Figure 5 in the column chart, the key posts, risk factors, accident or event types, and optimized risk degree values are marked, and through Figure 5 , one can have a intuitive and detailed understanding of the risks of various accidents or events caused by various risk factors. Figure 6The pie chart shows the proportion of different risk level accidents or events, and through Figure 6 It can be seen directly that in the process of the top cutting along with the empty roadway operation, the operation personnel of each post mainly faces general risk and greater risk, followed by low risk, and finally major risk.

[0111] Finally, after obtaining the above-optimized risk degree value and risk level, the initially prepared protection measures can be increased or improved, that is, the protection measures in the initially prepared construction process are optimized, and after the danger of the danger factors of each key post is reduced to the preset level or below, the construction is performed.

[0112] In summary, the embodiment provides a top cutting along with empty roadway operation method. After the construction process is prepared, the danger of the danger factors of the key post is quantitatively divided, that is, the risk level is divided, and the protection measures are increased or improved according to the divided risk level. After the danger of the danger factors of each key post is reduced to the preset level or below, the operation is performed according to the optimized construction process, which can greatly improve the safety of the operation.

[0113] Finally, it should be noted that in this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a" does not, without more constraints, exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0114] The above description of disclosed embodiments allows a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for cutting the top of a tunnel and retaining it along the gob, characterized in that: include: Preliminary development of construction procedures; Classify the risk factors of key positions involved in the construction process into risk levels; Optimize the protective measures in the construction process according to the classified risk levels until the risk level is reduced to the preset level or below; The top cutting and tunnel retaining operations are carried out according to the optimized construction process.

2. The method for retaining entry along the gob in a top cutting operation according to claim 1 is characterized in that: The step of classifying the risk factors of key positions involved in the construction process into risk levels includes: Division of key positions: Based on the preliminarily formulated construction process, key positions for the roof cutting and gob-side entry retention operation are divided; Risk identification: Identify the hazardous factors and possible accidents or incidents in key positions; Risk value calculation: Use R = L × S to calculate the risk value R of each risk factor leading to an accident, where L is the probability of each risk factor leading to an accident, and S is the severity of the consequences of the accident caused by each risk factor; Risk value optimization: Optimize the calculated risk value R according to the confidence level of the unascertained rational number; Risk level classification: Based on the optimized risk values, the risk level of accidents caused by various hazardous factors is divided.

3. The method for retaining entry along the gob in a top cutting operation according to claim 2 is characterized in that: In the key position division, the top cutting and goaf retaining operation is divided into the following key positions: reinforcement anchor drilling rig operator position, reinforcement anchor support worker position, directional top hole drilling worker position, blasting worker position, and single support worker position.

4. The method for top cutting and gob-side entry retaining according to claim 2 is characterized in that: When identifying the risk factors of key job positions, the job hazard analysis method is used.

5. The method for top cutting and gob-side entry retaining according to claim 2 is characterized in that: When calculating the risk value R, the probability L of each hazardous factor leading to an accident is assigned a value based on five aspects: whether the working environment is good, whether the equipment and facilities are intact, whether preventive measures are in place, the strength of personnel safety awareness, and whether the operating procedures are complete. Each aspect accounts for 1 point, for a total of 5 points. The higher the score, the greater the probability L of the corresponding hazardous factor leading to an accident.

6. The method for top cutting and gob-side entry retaining according to claim 5 is characterized in that: When calculating the risk value R, the severity S of the consequences of accidents caused by various hazardous factors is assigned a value based on three aspects: whether it causes casualties, whether it causes equipment damage, and whether it leads to work stoppage or production suspension. The severity of the consequences is assigned a score of 1 to 6. The higher the score, the more serious the consequences of the accident.

7. The method for top cutting and gob-side entry retaining according to claim 6 is characterized in that: When calculating the risk value R, at least five experts in relevant fields score the possibility L of each risk factor leading to an accident and the severity S of the consequences of the accident, and multiple risk values ​​R are calculated based on the expert scores.

8. The method for top cutting and gob-side entry retaining according to claim 7 is characterized in that: When optimizing the risk value R, first determine the credibility of the risk value R of each risk factor of each key position given by different scorers within the initial confidence interval, then determine the optimized confidence interval based on the credibility, and use the average value of the risk value R within the optimized confidence interval as the optimized risk value.

9. The method for retaining entry along the gob in top cutting according to claim 8 is characterized in that: According to the optimized risk value, the risk level is divided into low risk, general risk, greater risk and major risk. The risk value range of low risk is [1,3], the risk value range of general risk is [4,8], the risk value range of greater risk is [9,16], and the risk value range of major risk is [18,30].

10. The method for top cutting and gob-side entry retaining according to claim 9, characterized in that: The method further includes: drawing a safety risk comparison diagram for the top cutting and gob-side entry retaining operation according to the risk level, wherein the safety risk comparison diagram includes at least one of the following: a bar chart and a pie chart.

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