A method for determining the danger of percussion based on the amount of drill cuttings

Abstract

The present application relates to the field of mine dynamic disaster monitoring and early warning, and particularly relates to a method for determining impact risk based on drill cuttings quantity correction, comprising the following steps: step one: measuring normal drill cuttings quantity in an area near the work site without mining and geological structure influence; step two: constructing a drill hole at the work site, and measuring the discharged drill cuttings quantity, drill cuttings repose angle and coal density at different drill hole depths; step three: correcting the discharged drill cuttings quantity to obtain total drill cuttings quantity; step four: calculating total drill cuttings quantity corresponding total drill powder rate index; step five: comparing the total drill powder rate index with the drill powder rate index to determine the impact risk of the work site. The present application improves the precision of determining impact risk by drill cuttings method and reduces the possibility of misjudgment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mine dynamic disaster monitoring and early warning, and particularly relates to a method for determining impact danger based on drill cuttings quantity correction. BACKGROUND

[0002] With the increase of coal mining depth, rock burst disasters occur frequently, which seriously threatens the safety of personnel life and property. The drill cuttings method is a method for determining impact danger by drilling a hole at the work site, and determining the impact danger according to the drill cuttings quantity discharged during the drilling process, the change rule thereof and the related dynamic effect. Because it is reliable and practical, and convenient to operate, it becomes a method for determining impact danger and a means for testing the effect of disaster relief.

[0003] The amount of drill cuttings is related to the stress of coal mass. In order to get the accurate relationship between them, domestic and foreign coal workers have carried out a lot of in-depth research. Petuhov considered the dilatancy of the inelastic deformation zone around the borehole, introduced the loose coefficient, and obtained the relationship between the amount of drill cuttings and the stress of coal mass based on the Coulomb-Mohr yield criterion. However, the physical meaning of the loose coefficient is not clear, and the theory is not rigorous enough. Goei Genyoshi et al. divided the amount of drill cuttings into two parts. One part is the amount of drill cuttings of the cylindrical coal body with the same diameter as the borehole. The other part is the amount of drill cuttings generated by the displacement of the hole wall after the stress redistribution around the hole. The radius of the inelastic deformation zone is calculated according to the Castner equation or the modified Fenna formula. Then, the radial displacement of the hole wall is obtained based on the invariable volume condition of the inelastic deformation zone. Finally, the total amount of drill cuttings and the stress of coal mass are obtained after ignoring the elastic displacement. This method is completely based on the elastoplastic theory, has no other assumptions, and the theory is rigorous. However, it does not consider the dilatancy of the inelastic deformation zone. The strain softening characteristics of coal mass are not considered in the above methods. Zhao Benjun, Zhang Mengtao, and others considered the strain softening characteristics of coal mass, ignored the radial displacement of the elastic deformation zone, only calculated the radial displacement of the inelastic deformation zone, and obtained the calculation formula of the amount of drill cuttings by considering and not considering the dilatancy. However, the amount of drill cuttings generated by the collapse of the hole is not included in the calculation of the amount of drill cuttings. Li Zhonghua et al. believed that when the initial stress around the hole is large, the inelastic deformation zone formed by the stress redistribution after drilling is also large, and there is a limit stress value. When the initial stress is greater than the limit stress value, the hole wall will collapse and lose stability, and the collapsed coal powder will also be discharged as drill cuttings. Although the above researches have obtained different relationships between the amount of drill cuttings and the stress of coal mass, in practical applications, in addition to the influence of the stress state of surrounding rock and the physical and mechanical properties of coal and rock, the amount of drill cuttings is also affected by other factors. Tang Jupeng et al. studied the influence of drilling speed and drill rod diameter on the amount of drill cuttings. Li Zhonghua et al. studied the influence of drilling speed on the temperature of drill cuttings. Pan Yishan, Wang Hongtu, and Xu Lianman et al. studied the influence of drill cutting temperature on the amount of drill cuttings. The influence of the above factors leads to a large difference between the theoretical and experimental results and the amount of drill cuttings in the field. However, for the same work site, it is believed that the physical and mechanical parameters of coal mass, construction tools, and operation procedures are basically consistent, and the amount of drill cuttings is the result of the comprehensive action of the above factors.

[0004] In practical applications of the drill cuttings method, there is a discrepancy between the actual amount of drill cuttings discharged and the theoretical value. According to the principle of drill pipe cuttings removal, during drilling, the auger drill pipe rotates within the borehole, forming a spiral conveyor with the borehole wall. Drill cuttings from the bottom of the hole are transported backward by the spiral grooves of the drill pipe until they are discharged outside the hole. Drill cuttings holes in mines prone to rock bursts are typically spindle-shaped, narrow at both ends and wide in the middle. This results in some drill cuttings in the middle of the borehole not contacting the auger blades and failing to be discharged, leaving some drill cuttings remaining in the borehole. This portion of drill cuttings is often overlooked, leading to a lower measured amount of discharged drill cuttings. Especially near the peak bearing pressure, the borehole diameter is much larger than the drill pipe diameter, resulting in a large amount of residual drill cuttings and thus a lower discharged amount than the actual amount.

[0005] Therefore, a method for correcting the amount of drill cuttings that simultaneously considers the principles of the drill cuttings method and the drill pipe cuttings removal method is needed, and the impact risk should be determined accordingly, so as to improve the accuracy of the drill cuttings method in determining the impact risk and reduce the possibility of misjudgment. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an impact hazard determination method based on drill cuttings quantity correction, which addresses the shortcomings of the drill cuttings method. By correcting the amount of drill cuttings discharged, the measurement error of drill cuttings quantity is effectively reduced, the accuracy of the impact hazard determination method is improved, and the possibility of misjudgment is reduced.

[0007] To solve the above-mentioned technical problems, the technical method adopted in this invention is as follows: a method for determining impact hazard based on drill cuttings quantity correction, comprising the following steps:

[0008] Step 1: Measure the normal amount of drill cuttings (C) in an area near the work site where there is no mining activity or geological structure influence. i where i is the drilling depth;

[0009] Step 2: Drill holes at the work site and measure the amount of drill cuttings (M) removed at different drilling depths. pi The angle of repose α of drill cuttings and the density ρ of coal;

[0010] Step 3: Determine the amount of drill cuttings removed (M) at each drilling depth. pi The corresponding borehole diameter D is calculated. i Then, based on the borehole diameter D i Calculate the total amount of drill cuttings M zi The specific calculation formula is as follows:

[0011]

[0012]

[0013] In the formula, l is the interval for measuring drill cuttings, and M is the value of M. pirepresents the amount of discharged drill cuttings at different drilling depths, a represents the drill cuttings repose angle, p represents the coal density, d represents the drill rod diameter, and D i represents the drilling diameter obtained at different drilling depths;

[0014] Step four: according to the total amount of drill cuttings at each drilling depth, the total drilling rate index at each drilling depth is calculated respectively;

[0015] Step five: according to the size relationship between the total drilling rate index at each drilling depth and the drilling rate index indicator corresponding to the drilling depth, the impact risk of the work site is determined.

[0016] The specific determination method of step five is as follows:

[0017] If the total drilling rate index at one or more drilling depths exceeds the drilling rate index indicator, it is determined that the work site has potential impact risk;

[0018] If the total drilling rate index at one or more drilling depths is close to the drilling rate index indicator, it is determined that the work site has potential impact risk;

[0019] If the total drilling rate index at any drilling depth does not reach the drilling rate index indicator, it is determined that the work site has no impact risk.

[0020] In step one, the determination method of the normal drill cuttings amount is as follows: a plurality of drill holes are arranged in the area corresponding to the work site to be determined without mining and geological structure influence, the drilling depth reaches the original rock stress zone, the drill cuttings amount per meter of each drill hole is measured and the average value is calculated as the normal drill cuttings amount per meter c j .

[0021] In step two, the determination method of the discharged drill cuttings amount is as follows: a drill hole is arranged at the work site to be determined, the discharged drill cuttings amount per meter M pj is collected, weighed and recorded during the drilling process, j is the drilling depth, and the dynamic effects such as drill sticking and drill sucking and the corresponding drilling depths are recorded.

[0022] In step two, the determination method of the drill cuttings repose angle is the injection angle method or the discharge angle method;

[0023] The injection angle method is as follows: multiple drill cuttings at different drilling depths are selected and injected into different flat plates, the average value of the angle of the conical surface formed by the drill cuttings on each flat plate is recorded, which is the drill cuttings repose angle;

[0024] The discharge angle method specifically comprises: selecting multiple drillings of different drilling depths, respectively injecting the drillings into a circular plate until the drillings are accumulated to the edge of the circular plate and discharged from the edge, and recording the average value of the angle of the conical surface formed by the drillings on the circular plate at this time, which is the repose angle of the drillings.

[0025] In the second step, the determination method of the coal body density is as follows: adopting the wax sealing method, first, the mass of the coal block is determined, then the coal block is immersed in the melted paraffin to wrap a wax shell to keep the complete shape; the mass of the sample with the wax shell in the air and in water is respectively obtained, according to the buoyancy principle, the volume of the sample and the coal body density are calculated.

[0026] In the fourth step, the calculation formula of the total drilling powder rate index at each drilling depth is as follows:

[0027] Total drilling powder rate index = total drilling amount M zi / normal drilling amount C i .

[0028] In the fifth step, when the ratio of the drilling depth to the roadway height is less than or equal to 1.5, the drilling powder rate index is 1.5; when the ratio of the drilling depth to the roadway height is greater than 1.5 and less than or equal to 3, the drilling powder rate index is 2; when the ratio of the drilling depth to the roadway height is greater than 3, the drilling powder rate index is 3.

[0029] Compared with the prior art, the impact danger determination method based on drilling powder correction has the following advantages: the drilling powder is regarded as the result of the comprehensive action of many factors such as surrounding rock stress, coal body physical and mechanical properties and drilling conditions, the drilling discharge is regarded as a "black box", the discharged drilling powder is regarded as an output result, the quantitative relationship between the discharged drilling powder and the drilling diameter is established according to the drilling powder method theory, the discharged drilling powder is corrected combined with the drilling rod discharge principle, and the corrected total drilling powder is used to replace the uncorrected discharged drilling powder to determine the impact danger, so that the measurement error of the discharged drilling powder is reduced, the accuracy of the drilling powder method in determining the impact danger is improved, and the possibility of misjudgment is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is a schematic diagram for determination of the repose angle of drillings, (a) injection angle method; (b) discharge method;

[0031] Figure 2 It is a schematic diagram for drilling powder amount in each part of the drilling;

[0032] Figure 3 It is a schematic diagram for no impact danger after correction;

[0033] Figure 4 It is a schematic diagram for potential impact danger after correction;

[0034] Figure 5The diagram after correction has impact danger. DETAILED DESCRIPTION

[0035] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall into the scope of protection of the present application.

[0036] Figures 1-4 The preferred embodiments of the present application are shown and analyzed in detail.

[0037] As Figures 1-4 shown in a kind of impact danger judging method based on drilling cuttings quantity correction, comprising the following steps:

[0038] Step one: normal drilling cuttings quantity is determined in the area without mining and geological structure influence near work site.

[0039] In the step one, the determination method of normal drilling cuttings quantity is: a plurality of drill holes are arranged in the area without mining and geological structure influence corresponding to the work site to be judged, the drill hole depth reaches the original rock stress zone, the drilling cuttings quantity of each meter of each drill hole is determined and the average value is calculated to be the normal drilling cuttings quantity c j Per meter of the work site.

[0040] Specifically, the determination method is: in the working face near the area not affected by mining, a drill hole is arranged every 10-30 m, the drill hole depth reaches the original rock stress zone; five measuring points are selected in turn, the drilling cuttings mass of each meter of the five measuring points is recorded respectively, and the average value is obtained, that is, the normal drilling cuttings quantity of different drill hole depths.

[0041] Step two: drill holes are constructed at the work site, and the drilling cuttings quantity, drilling cuttings angle of repose and coal density are determined.

[0042] In the step two, the determination method of the drilling cuttings quantity is: a drill hole is arranged at the work site to be judged, the drilling cuttings quantity M pj Per meter in the drilling process is collected, weighed and recorded, and the drilling effect such as drill jamming and drill sucking and the corresponding drill hole depth are recorded simultaneously.

[0043] Specifically, the determination method of the drilling cuttings quantity is: a plurality of measuring points are selected at the work site, drill holes are arranged, the drill hole depth reaches the original rock stress zone, and the average value of the drilling cuttings quantity per meter of the measuring points is recorded, that is, the drilling cuttings quantity of different drill hole depths of the measuring points.

[0044] In step two, the method for determining the drill cuttings repose angle is either the injection angle method or the discharge angle method. The injection angle method specifically involves selecting multiple drill cuttings of different drilling depths and injecting them onto different flat plates. The average angle of the conical slope formed by the drill cuttings on each plate is recorded, which is the drill cuttings repose angle. The discharge angle method specifically involves selecting multiple drill cuttings of different drilling depths and injecting them onto a circular plate until the drill cuttings accumulate to the edge of the circular plate and are discharged from the edge. The average angle of the conical slope formed by the drill cuttings on the circular plate at this time is recorded, which is the drill cuttings repose angle.

[0045] like Figure 1 Figure (a) shows the injection angle method. Multiple drill cuttings from different drilling depths are selected and injected onto a large flat plate. The average angle of the conical slope formed by the drill cuttings is recorded, which is the drill cutting repose angle α. Figure 1 Figure (b) shows the discharge angle method. Multiple drill cuttings of different drilling depths are selected and injected into a circular plate with a smaller diameter. When the drill cuttings accumulate to the edge of the circular plate, they are discharged from the edge. The average value of the angle of the cone-shaped inclined plane formed by the drill cuttings on the circular plate at this time is recorded, which is the drill cuttings repose angle α.

[0046] In step two, the method for determining the density of the coal body is as follows: using the wax sealing method, first determine the mass of the coal block, then immerse the coal block in melted paraffin wax to coat it with a layer of wax shell to maintain its complete shape; by weighing the mass of the sample with the wax shell in air and water respectively, the sample volume and coal body density are calculated based on the principle of buoyancy.

[0047] Step 3: Correct the amount of drill cuttings discharged to obtain the total amount of drill cuttings.

[0048] Specifically, in step three, the amount of drill cuttings discharged at each borehole depth, M, is... pi The corresponding borehole diameter D is calculated. i Then, based on the borehole diameter D i Calculate the total amount of drill cuttings M zi The specific calculation formula is as follows:

[0049]

[0050]

[0051] In the formula, l is the interval for measuring drill cuttings, and M is the value of M. pi The values ​​represent the amount of drill cuttings discharged at different borehole depths, α represents the angle of repose of the drill cuttings, ρ represents the coal density, d represents the drill pipe diameter, and D... i This indicates the borehole diameter at different borehole depths;

[0052] like Figure 2As shown, a vertical line OA is drawn from the center of the drill hole O downward, and a ray is drawn from point O at an angle of α with the vertical line. The ray intersects the outer edge of the drill rod at point B, and a tangent to the outer edge of the drill rod is drawn through point B, intersecting the hole wall at point C. BC is the drill cuttings accumulation slope. Similarly, the other side drill cuttings accumulation slope DE can be obtained. In the cross section of the drill hole, the "U" shaped part enclosed by the drill cuttings accumulation slopes BC and DE, the inferior arc BD of the outer edge of the drill rod, and the circular arc CAE of the hole wall is the residual drill cuttings, and the remaining part is the discharged drill cuttings. The sum of the amount of residual drill cuttings and the amount of discharged drill cuttings is the total amount of drill cuttings, i.e. the corrected amount of drill cuttings.

[0053] Therefore, in this embodiment, the correction method of the amount of discharged drill cuttings is as follows: the amount of discharged drill cuttings M pi at different drill hole depths is divided by the normal amount of drill cuttings C i at the corresponding drill hole depth, and the drill cuttings angle of repose α, the coal body density ρ, and the drill rod diameter d are substituted into formula (1) to obtain the drill hole diameter D i at different drill hole depths. zi Then, the drill hole diameter D zi calculated by formula (1) is substituted into formula (2) to obtain the total amount of drill cuttings M pi at different drill hole depths.

[0054] Step four: calculate the total drill cuttings rate index corresponding to the total amount of drill cuttings. The calculation method is as follows: the amount of discharged drill cuttings and the total amount of drill cuttings at different drill hole depths are respectively divided by the normal amount of drill cuttings at the corresponding drill hole depth, and the discharged drill cuttings rate index and the total drill cuttings rate index at different drill hole depths are obtained. That is, the discharged drill cuttings rate index = the amount of discharged drill cuttings M pi / the normal amount of drill cuttings C i ; the total drill cuttings rate index = the total amount of drill cuttings M zi / the normal amount of drill cuttings C i .

[0055] Step five: compare the total drill cuttings rate index corresponding to the corrected total amount of drill cuttings with the drill cuttings rate index to determine the impact risk of the work site.

[0056] In this embodiment, when the ratio of the drill hole depth to the height of the roadway is less than or equal to 1.5, greater than 1.5 and less than or equal to 3, and greater than 3, the drill cuttings rate index is 1.5, 2, and 3 respectively. That is, when the ratio of the drill hole depth to the height of the roadway is less than or equal to 1.5, the drill cuttings rate index is 1.5; when the ratio of the drill hole depth to the height of the roadway is greater than 1.5 and less than or equal to 3, the drill cuttings rate index is 2; and when the ratio of the drill hole depth to the height of the roadway is greater than 3, the drill cuttings rate index is 3.

[0057] Specifically, the specific determination method of the impact risk of the work site is as follows:

[0058] (1) If the total drilling dust rate index at one or several drilling depths exceeds the drilling dust rate index indicator, it is determined that the working site has potential impact danger;

[0059] (2) If the total drilling dust rate index at one or several drilling depths is close to the drilling dust rate index indicator, it is determined that the working site has potential impact danger;

[0060] (3) If the total drilling dust rate index at any drilling depth is less than the drilling dust rate index indicator, it is determined that the working site has no impact danger.

[0061] Further, if a working site has potential impact danger, it needs to be further determined according to the dynamic effect on site. If there is a dynamic effect such as sticking, sticking, vibration, sound, etc. on site, it is determined that the working site has impact danger. If there is no obvious dynamic effect, it is determined that the working site has no impact danger.

[0062] Specifically, in the embodiment, the total drilling dust rate index close to the drilling dust rate index indicator means that the total drilling dust rate index is less than the value of the corresponding drilling dust rate index indicator, and the difference between them is less than 10%, or the total drilling dust rate index is greater than the value of the drilling dust rate index indicator corresponding to the previous drilling depth.

[0063] In the embodiment, according to the size relationship between the total drilling dust rate index and the drilling dust rate index indicator, the impact danger determination result is divided into three cases: ① No impact danger after correction. The total drilling dust rate index after correction does not reach the drilling dust rate index indicator at any drilling depth, so the working site has no impact danger; ② Potential impact danger after correction. After correction, the total drilling dust rate index at one or several places is close to the indicator, so the working site has potential impact danger, which needs to be further determined according to the dynamic effect on site. If there is a dynamic effect such as sticking, sticking, vibration, sound, etc. on site, it is determined that the working site has impact danger. If there is no obvious dynamic effect, it is determined that the working site has no impact danger; ③ Impact danger after correction. After correction, the total drilling dust rate index at one or several places is significantly higher than the indicator, so the working site has impact danger.

[0064] Next, taking three mines as the objects to be determined, the impact danger of the working sites of the three mines is determined by using the method provided by the present application, and the specific steps are as follows:

[0065] (1) In the normal stress zone outside the working face mining influence range (200 m ahead of the working face), 10 drill holes were arranged in the recovery roadway, the drilling parameters were as follows: drill hole diameter 42 mm, hole depth 10 m, hole spacing 10 m, single row arrangement, and the drilling direction was parallel to the coal seam and perpendicular to the roadway sides. During drilling, the coal powder was collected with a professional bag, the weight of the coal powder was measured with a spring scale, the first meter of drill cuttings was discarded, the second meter was recorded, and the drill cuttings were measured once every 1 drill rod and recorded in a special table, and the recording results were accurate to two decimal places. The average value of the coal powder amount per meter of each hole was taken as the normal drill cuttings amount per meter of the drill hole of the working face, see Table 1.

[0066] Table 1 Normal drill cuttings amount of each mine

[0067]

[0068] (2) Drill holes were constructed at equal intervals on both sides of the roadway at the working site, the drilling spacing was 20 m, the hole depth was 10 m, the single row arrangement was arranged, and the drilling direction was parallel to the coal seam and perpendicular to the roadway sides. During drilling, the coal powder was collected with a professional bag, the weight of the coal powder was measured with a spring scale, the first meter of drill cuttings was discarded, the second meter was recorded, and the drill cuttings were measured once every 1 drill rod and recorded in a special table, and the recording results were accurate to two decimal places. The average value of the coal powder amount per meter of each hole was taken as the normal drill cuttings amount per meter of the drill hole of the working face, see Table 1.

[0069] The injection angle method (or discharge angle method) was used to select multiple drill cuttings of different drilling depths, which were injected into a large flat plate, and the average value of the angle of the conical surface formed by the drill cuttings was recorded, which was the rest angle of the drill cuttings.

[0070] First, the mass of the measuring cylinder was measured, then multiple drill cuttings of different drilling depths were selected and poured into the measuring cylinder, the volume of the drill cuttings and the total mass of the measuring cylinder and the drill cuttings were measured and recorded, the total mass of the measuring cylinder and the drill cuttings was subtracted from the mass of the measuring cylinder, then divided by the volume of the drill cuttings, and the average value was obtained, which was the density of the coal body.

[0071] The obtained discharge drill cuttings amount, drill cuttings rest angle and coal body density are shown in Table 2.

[0072] Table 2 Discharge drill cuttings amount and related parameters of each mine

[0073]

[0074] (3) According to formula (1) and formula (2), the discharge drill cuttings amount at different drilling depths of the three mines was corrected, and the corrected drill cuttings amount, i.e. the total drill cuttings amount, was obtained, see Table 3.

[0075] Table 3 Total drill cuttings amount of each mine

[0076]

[0077] (4) Respectively, the discharge of drill cuttings, total drill cuttings divided by the normal amount of drill cuttings, the discharge of drill powder rate index and total drill powder rate index, see Table 4.

[0078] Table 4 of each mine discharge drill powder rate index and total drill powder rate index

[0079]

[0080]

[0081] As can be seen in Table 4, the total drill powder rate index obtained by correcting the amount of drill cuttings in this embodiment is greater than the discharge of drill powder rate index before correction, and the accuracy of the impact risk determination can be improved.

[0082] (5) In order to compare the size relationship between the total drill powder rate index and the drill powder rate index, the correction results of the three mines are plotted respectively.

[0083] ① As shown in Figure 3 , the total drill powder rate index of the working site of Baojishan Coal Mine at any drilling depth is less than the drill powder rate index, that is, there is no impact risk after correction. When drilling holes at the working site, there is no dynamic effect in the drilling process, indicating that there is no impact risk at the working site.

[0084] ② As shown in Figure 4 , the hole depth of the working site of Fengying Coal Mine is 3, that is, the drilling depth is 14m, and the corresponding total drill powder rate index is 2.04. Although it is less than the corresponding drill powder rate index, it is greater than the value of the drill powder rate index corresponding to the previous drilling depth (2.0), so the total drill powder rate index of the drilling hole is very close to the drill powder rate index, that is, there is a potential impact risk after correction. Combined with the construction of the drilling hole, there is a slight sticking, sticking, and top drilling phenomenon, accompanied by a weak coal explosion, indicating that the working site has an impact risk.

[0085] ③ As shown in Figure 5 , there are many places where the total drill powder rate index of the working site of Changping Coal Mine is significantly higher than the drill powder rate index, that is, there is an impact risk after correction. When drilling holes at the working site, there are obvious sticking, sticking, sticking, abnormal sound and impact in the hole, and there are many anchor cables being pulled off, indicating that the working site has an impact risk and needs to take preventive measures.

[0086] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining a danger of a blow based on a correction of a cuttings amount, characterized by, The method comprises the following steps: Step One: Measure normal cuttings in areas near the work site that are free of mining and geologic structure influences Ci , i D = drilling depth Step two: Drilling holes at the work site and measuring the amount of drill cuttings at different depths Mpi , the angle of repose of drill cuttings α , and the density of the coal body ρ ; Step three: Calculate the total amount of drill cuttings by the amount of drill cuttings discharged at each drilling depth Mpi Calculate the corresponding drilling diameter Di Then, according to the drilling diameter Di Calculate the total amount of drill cuttings Mzi The specific calculation formula is: ； ； wherein, l is the drilling cuttings measurement interval, Mpi represents the amount of discharged drilling cuttings at different drilling depths, α represents the angle of repose of the drilling cuttings, ρ represents the density of the coal body, d represents the diameter of the drill pipe, Di represents the drilling diameter obtained at different drilling depths; Step four: according to the total drilling dust amount at each drilling depth, the total drilling dust rate index at each drilling depth is calculated respectively; Step five: according to the size relationship between the total drilling dust rate index at each drilling depth and the drilling dust rate index indicator corresponding to the drilling depth, the impact risk of the work site is determined; In the step four, the calculation formula of the total drilling dust rate index at each drilling depth is as follows: Total Drilling Powder Rate Index = Total Drilling Dust Quantity Mzi Normal Drilling Dust Quantity Ci .

2. The method according to claim 1, wherein The specific determination method of the step five is as follows: If the total drilling dust rate index at one or several drilling depths exceeds the drilling dust rate index indicator, it is determined that the work site has a potential impact risk; If the total drilling dust rate index at any drilling depth does not reach the drilling dust rate index indicator, it is determined that the work site has no impact risk.

3. The method according to claim 1, wherein The method for measuring the normal drilling cuttings amount in step one is as follows: arranging multiple drill holes in the area corresponding to the working site to be determined, which is not affected by mining and geological structure, drilling to the depth of the original rock stress zone, measuring the drilling cuttings amount per meter of each drill hole and calculating the average value as the normal drilling cuttings amount per meter of the working site cj .

4. The method according to claim 1, wherein, The method for measuring the amount of discharged drill cuttings in the second step is: arranging a drill hole at the working site to be determined, collecting, weighing and recording the amount of discharged drill cuttings per meter in the drilling process Mpj , j is the drilling depth, and the power effect occurring in the drilling process and the corresponding drilling depth are recorded.

5. The method according to claim 1, wherein In the step two, the determination method of the drilling dust repose angle is the injection angle method or the discharge angle method; The injection angle method specifically is: multiple drilling dusts at different drilling depths are selected and injected into different flat plates respectively, and the average value of the angle of the conical surface formed by the drilling dust on each flat plate is recorded, that is, the drilling dust repose angle; The discharge angle method specifically is: multiple drilling dusts at different drilling depths are selected and injected into a circular plate until the drilling dusts accumulate to the edge of the circular plate and are discharged from the edge, and the average value of the angle of the conical surface formed by the drilling dust on the circular plate at this time is recorded, that is, the drilling dust repose angle.

6. The method according to claim 1, wherein In the step two, the determination method of the coal body density is: the wax sealing method is adopted, the mass of the coal block is first determined, and then the coal block is immersed in melted paraffin to wrap a layer of wax shell to maintain the complete shape; the mass of the sample with the wax shell in air and water is respectively obtained, and according to the principle of buoyancy, the volume of the sample and the coal body density are calculated.

7. The method according to claim 1, wherein In the step five, when the ratio of the drilling depth to the height of the roadway is less than or equal to 1.5, the drilling dust rate index indicator is 1.5; when the ratio of the drilling depth to the height of the roadway is greater than 1.5 and less than or equal to 3, the drilling dust rate index indicator is 2, and when the ratio of the drilling depth to the height of the roadway is greater than 3, the drilling dust rate index indicator is 3.

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