A method for identifying grout diffusion range of long borehole grouting in coal mine floor

Abstract

The application discloses a coal mine floor long borehole grouting slurry diffusion range identification method; by adding a known amount of different isotopes in each branch hole slurry, after mixing evenly, the slurry is introduced into each target area grouting hole; after the slurry diffuses and solidifies, drill cuttings of different depths and different widths of each branch hole on the grouting path are sampled, by analyzing the type and concentration of isotopes in the drill cuttings, the diffusion radius and range of the slurry can be identified; the statistical test results are obtained, and the average radius of the slurry diffusion is calculated; considering the economic reasons, the inter-hole spacing is optimized according to the isotope detection data, so as to reduce the cost of grouting and transforming the floor rock mass; the reinforced rock mass is tested and evaluated, so that the grouting reinforcement reaches the expected effect. The method provides higher accuracy and efficiency in evaluating the slurry diffusion degree, improves the effectiveness and reliability of the grouting range and effect evaluation, and reduces the grouting cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mining engineering, in particular to a coal mine floor long borehole grouting slurry diffusion range identification method. BACKGROUND

[0002] Coal mine floor long borehole grouting is a key support technology in underground engineering, and its purpose is to fill and reinforce the cavities inside the coal mine floor through grouting means, thereby significantly improving the stability and safety of the working face. However, in engineering practice, the traditional grouting method faces major challenges, namely how to accurately evaluate the diffusion range of grouting slurry inside the floor to ensure that the support effect meets the design requirements and guarantees the engineering quality.

[0003] The traditional grouting slurry diffusion range evaluation method relies mainly on geological survey and physical test. These methods are often restricted by the complex underground environment and technical limitations in practical application, making it difficult to obtain accurate and reliable diffusion range data.

[0004] Among them, the existing patent technology with patent number CN114483010A and patent name "a method for detecting slurry diffusion range" specifically discloses "the method includes: determining a target interval; drilling the target interval through a preset main hole and a preset horizontal branch hole to obtain a drilling fluid loss position; determining a grouting position according to the drilling fluid loss position; conducting resistivity detection before grouting at the grouting position to obtain a first while-drilling azimuth resistivity; conducting resistivity detection after grouting at the grouting position to obtain a second while-drilling azimuth resistivity; determining the slurry diffusion range according to the first while-drilling azimuth resistivity and the second while-drilling azimuth resistivity", the above technology obtains the slurry diffusion range under different geological structure types through resistivity detection of the main hole and the horizontal branch hole within the treatment range, but such a setting does not directly detect the slurry, and in actual application, it will also be restricted by the complex underground environment and technical limitations, affecting the detection accuracy.

[0005] Therefore, it is urgent to explore a new evaluation method to improve the identification and evaluation accuracy of the diffusion range of coal mine floor multi-hole grouting slurry. SUMMARY

[0006] The technical problem to be solved by the present application is how to provide a method for efficiently and accurately evaluating the diffusion range of coal mine floor multi-hole grouting slurry, and optimizing the design scheme of underground engineering support to ensure that grouting can cover the area that needs to be reinforced.

[0007] To solve the above technical problems, the present application provides the following technical scheme:

[0008] A coal mine floor long borehole grouting slurry diffusion range identification method, comprising the following steps:

[0009] S1, first open section borehole

[0010] The position of the orifice of the long borehole area grouting hole and the drilling depth are determined, a predetermined drilling position is set, the drilling machine is used to drill at the predetermined position, the diameter and position of the branch hole are determined, and the first open section is drilled and grouted;

[0011] S2, isotope delivery

[0012] An appropriate radioactive isotope labeled component is selected, and different types of isotopes are pre-delivered to the grouting liquid of different branch holes to make them uniformly distributed;

[0013] S3, first open section grouting

[0014] Under the action of grouting pressure, different isotopes spread along the grouting liquid from each branch hole to the fissures in the coal seam floor, and after the first open section isotope delivery is completed, the first open section grouting hole is temporarily blocked;

[0015] S4, first core sampling

[0016] After two days of grouting, cores are drilled at different depths and different widths of the same branch hole in the coal seam floor at the excavation face, and the types and concentrations of isotopes are analyzed and determined to check the diffusion effect of grouting;

[0017] S5, second core sampling

[0018] Cores are drilled at different depths of the same branch hole in the coal seam floor at the excavation face, and the concentration distribution of the isotope labeled component is analyzed and determined to check the diffusion effect of the grouting liquid;

[0019] S6, branch hole optimization

[0020] According to the isotope detection results, the average radius of the grouting liquid diffusion of each branch hole is calculated, the diffusion range and intersection area between the holes are analyzed, and then the hole spacing is optimized, and the second open section branch hole construction is carried out according to the fault fissure grouting condition.

[0021] The present application mixes different isotopes with grouting slurry and injects them by determining the position and number of holes that need to be grouted, drills and samples different depths and widths of each branch hole on the grouting path, detects the types and concentrations of isotopes, and counts the diffusion of the grouting liquid, confirms the development of the fault fissure, sets a supplementary hole for the first open section grouting hole according to the data results, and optimizes the hole spacing of the second open section. The present application can efficiently and accurately evaluate the diffusion range of the coal mine floor multi-hole grouting slurry, optimize the underground engineering support design scheme, and ensure that the grouting can cover the area that needs to be reinforced.

[0022] As a further scheme of the present application: the hydrogen and oxygen isotopes of water are selected as the isotopic tracer in step S2.

[0023] As a further scheme of the present application: the hydrogen and oxygen isotopes of water are selected as the isotopic tracer in step S2. 16 O or H2 17 O or H2 18 O.

[0024] As a further scheme of the present application: different isotopic tracers are selected for the grouting liquid in the branch hole in step S3, and the different isotopes are mixed with the grouting liquid in the same proportion and then injected into the open section drill hole.

[0025] As a further scheme of the present application: the rock cores are drilled every 10m at different widths at the same depth of the floor in step S4, the types and concentrations of isotopes are determined, and the diffusion radius and intersection area between the holes are analyzed.

[0026] As a further scheme of the present application: the rock cores are drilled every 30m at different depths in the same branch hole in step S5, the types of isotopes are determined, and the fracture distribution and rock mass strength of the fault fracture zone are analyzed.

[0027] As a further scheme of the present application: the mass spectrometer is used for the isotope determination.

[0028] As a further scheme of the present application: the specific steps for optimizing the hole spacing in step S6 are as follows:

[0029] S61, from the lateral grouting liquid expansion distance, the lateral diffusion radius of the grouting liquid is preset as X1m, and the interval between the directional branch holes is 2X1m;

[0030] S62, the actual diffusion radius of the open section branch hole is X2m, if X2m>X1m, the expected diffusion distance value is exceeded, and the grouting construction target is reached; at this time, the hole spacing is optimized, and the hole spacing is increased from 2X1m to 2X2m;

[0031] S63, the actual diffusion radius of the open section branch hole is X3m, if X3mX1m, the expected diffusion distance value is not reached, and the supplementary injection hole is arranged between the open section branch holes.

[0032] As a further scheme of the present application: during the grouting process in step S3, the pump quantity, the grouting liquid density (i.e. the specific gravity), the pump pressure, and the orifice pressure are recorded every 30-40min, and the cement consumption is calculated.

[0033] Compared with the prior art, the present application has the following beneficial effects:

[0034] Firstly, the application mixes different isotopes with grouting slurry and injects them by determining the position and the number of holes needing grouting reinforcement, drills cuttings at different depths and different widths of each branch hole on the grouting path, detects the type and concentration of isotopes, and counts the diffusion of slurry, confirms the development of fault fissure, sets a supplementary hole for the first section of the grouting hole according to the data results, and optimizes the hole spacing of the second section, the application can efficiently and accurately evaluate the diffusion range of the coal floor multi-hole grouting slurry, optimize the underground engineering support design scheme, and ensure that the grouting can cover the area needing reinforcement.

[0035] Secondly, the application can cover the whole area of the tunneling working face as much as possible, accurately evaluate the diffusion range of the slurry, improve the effect and durability of the engineering support, and better assist the drilling work of the coal floor by pre-investigating the hydrogeological data of the grouting area, select appropriate hole spacing, avoid unnecessary waste of slurry, reduce the construction risk caused by insufficient or excessive grouting, and greatly improve the construction efficiency of grouting. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a step schematic diagram of the coal floor long-hole grouting slurry diffusion range identification method of the embodiment of the application;

[0037] Figure 2 It is a coal floor multi-hole scheme design and longitudinal core drilling scheme schematic diagram of the embodiment of the application;

[0038] Figure 3 It is a transverse core drilling scheme design and slurry diffusion radius statistical diagram of the embodiment of the application; DETAILED DESCRIPTION

[0039] To make the purpose, technical scheme and advantages of the embodiment of the application clearer, the technical scheme in the embodiment of the application will be described clearly and completely below in combination with the embodiment of the application. Obviously, the described embodiment is a part of the embodiments of the application, rather than all the embodiments. Based on the embodiment in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0040] Embodiment 1

[0041] To further illustrate the method for identifying the diffusion range of the coal floor multi-hole grouting slurry by isotopes, taking the mining floor area of the west wing of a certain mine as an example, the fault throw of this coal mining area is large, the cutting level is deep, when the mining activity of the mine is close, the groundwater head pressure loses balance, and the fault fracture zone often becomes a water inrush port, therefore, the multi-hole grouting reinforcement treatment is carried out at the position where the coal seam and the limestone are "opposite", the method of identifying the diffusion range of the slurry by the isotope tracing technology is adopted to ensure safe mining, and the specific steps include:

[0042] Step S1, first open section drilling

[0043] Collect hydrogeological data of the coal mining area, collect local terrain, water system and weather conditions, determine the hole position and drilling depth of the long borehole area grouting hole, set the predetermined drilling position, and determine the drilling layout principle and drilling engineering quantity according to the drilling position, use the drilling machine to drill the predetermined position, determine the branch hole diameter and position, and then drill the first open section.

[0044] Specifically, this example takes the W hole group as an example, sets up a main hole W with five branch holes, i.e. branch hole W1, branch hole W2, branch hole W3, branch hole W4, branch hole W5, etc. The number of branch holes is determined according to the actual situation on site, and this application only takes five branch holes as an example for illustration. First, the main hole wellhead position of the long borehole area grouting hole is determined as X: 3630804.047m, Y: 441254.458m, Z: +24.678m, and the above position is based on the geodetic coordinate system.

[0045] The lower branch hole adopts a strip-shaped branch hole. From the perspective of the lateral grout expansion distance, the expected lateral diffusion radius of the grout is X1=30m, and the average plane spacing of the directional branch hole is 2X1=60m. The final hole depth of the branch hole W1 is 1687m; the final hole depth of the branch hole W2 is 1713m; the final hole depth of the branch hole W3 is 1963m; the final hole depth of the branch hole W4 is 1821m; and the final hole depth of the branch hole W5 is 1932m. The bottom plate drilling machine is used to drill the predetermined position, and the branch hole diameter is 152mm.

[0046] Step S2, isotope injection

[0047] Select appropriate radioactive isotope labeled components, and pre-inject different types of isotopes into the grouting liquid of different branch holes to make them uniformly distributed.

[0048] Specifically, after the drilling of the first open section is completed, the water pressure test is carried out, and then the grouting process is carried out. A temporary grouting station is built at the well site, which is equipped with 2 sets of grouting system and 3 grouting pumps (1 set of 3ZB-35 type grouting pump, 2 sets of 3NB-260 type grouting pump), 1 clean water pool, 2 mixing pools and 2 cement ash tanks. The isotope tracer is selected from hydrogen and oxygen isotopes of water, such as H216O, H217O, H218O, etc. Different types of isotope tracers are selected for the grouting liquid of each branch hole, and different types of isotopes are mixed uniformly with the grouting liquid at the same ratio and then injected into the first open section drilling hole.

[0049] Step S3, first open section grouting

[0050] Specifically, the slurry is driven by the initial pressure P, and after passing through the hole with a certain diameter, depth and length, the slurry diffuses into the rock fissure in an open section hole; during the grouting process, the pump volume, slurry density (i.e. specific gravity), pump pressure and orifice pressure are recorded every half hour, and the cement consumption is calculated; under the action of grouting pressure, different isotopes from the branch hole spread to the fissures in the coal seam floor along with the diffusion of the grouting liquid, and after the isotope injection in the first section is completed, the first section grouting hole is temporarily plugged;

[0051] Step S4, first core sampling

[0052] After two days of grouting, cores are drilled at different depths in the same branch hole towards the coal seam floor at the excavation face, and the concentration distribution of the isotope labeled component is determined by analysis to check the diffusion effect of the grouting liquid.

[0053] Specifically, after two days of grouting, cores are drilled every 30m longitudinally at different depths in the same branch hole towards the floor at the excavation face, as shown in Figure 2 As shown in the coal mine floor multi-hole scheme design and longitudinal core drilling scheme design, the types and concentrations of isotopes are determined by analysis to analyze the diffusion radius and intersection area between holes, and to check the diffusion effect of grouting; it should be noted that the types and concentrations of isotopes in cores drilled at different depths and widths are determined by mass spectrometry, which determines the concentration distribution of the isotope labeled component by analyzing the relative abundance of different isotopes in the sample, and the mass spectrometer can be used for measurement to check the diffusion effect of the grouting liquid.

[0054] Step S5, second core sampling

[0055] After two days of grouting, cores are drilled at different widths at the same depth in different branch holes towards the coal seam floor at the excavation face, and the types and concentrations of isotopes are determined by analysis to check the diffusion effect of grouting.

[0056] Specifically, cores are drilled every 10m horizontally at different widths at the same depth in different branch holes towards the floor at the excavation face, as shown in Figure 3 As shown in the horizontal core drilling scheme and grouting diffusion radius statistical diagram, the types and concentrations of isotopes are determined by analysis to analyze the diffusion radius and intersection area between holes, and to check the diffusion effect of grouting; it should be noted that the types and concentrations of isotopes in cores drilled at different depths and widths are determined by mass spectrometry, which determines the concentration distribution of the isotope labeled component by analyzing the relative abundance of different isotopes in the sample, and the mass spectrometer can be used for measurement to check the diffusion effect of the grouting liquid.

[0057] Step S6, branch hole optimization

[0058] According to the isotopic detection result, the average radius of slurry diffusion of each branch hole is calculated, the diffusion range and intersection area between holes are analyzed, and then the hole spacing is optimized, and the two-opening section branch drilling is conducted according to the fault fracture grouting condition.

[0059] Further, from the lateral slurry expansion distance, the preset slurry lateral diffusion radius is X1m, and the directional branch hole plane spacing is 2X1m; the actual diffusion radius of the one-opening section branch hole is X2m, if X2m>X1m, the expected diffusion distance value is exceeded, and the grouting construction target is reached; at this time, the hole spacing is optimized, and the hole spacing is increased from 2X1m to 2X2m; the actual diffusion radius of the one-opening section branch hole is X3m, if X3mX1m, the expected diffusion distance value is not reached, and the supplementary injection hole is arranged between the one-opening section branch holes.

[0060] Specifically, if the actual average diffusion radius of the one-opening section branch hole is X2=37m, the expected diffusion distance value is exceeded, the grouting construction target is reached, the hole spacing is optimized, the hole spacing is increased from 2X1=60m to 2X2=74m, and the grouting amount is reduced.

[0061] If the actual average diffusion radius of the one-opening section branch hole is X3=23m, the expected diffusion distance value is not reached, the supplementary injection hole is arranged between the one-opening section branch holes, and then the two-opening section branch drilling is conducted according to the fault fracture grouting condition.

[0062] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some 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 spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for identifying the grout diffusion range of long-hole grouting in a coal mine floor, characterized in that, It comprises the following steps: S1, first open section drilling The position of the hole mouth of the long drilling area grouting hole and the drilling depth are determined, a predetermined drilling position is set, the drilling machine is used to drill at the predetermined position, the diameter and position of the branch hole are determined, and the first open section is drilled and grouted; S2, isotope injection Suitable radioactive isotope markers are selected, different types of isotopes are injected into the grouting fluid of different branch holes in advance, and they are uniformly distributed; S3, first open section grouting Under the action of grouting pressure, different types of isotopes from each branch hole spread along the grouting fluid to the fissures in the coal seam floor, and after the first open section isotope injection is completed, the first open section grouting hole is temporarily blocked; S4, first core sampling After two days of grouting, drill cores are taken at different depths of the same branch hole in the coal seam floor at the excavation face, the concentration distribution of the isotope marker is analyzed and determined, and the diffusion effect of the grouting fluid is checked; S5, second core sampling Drill cores are taken at different widths of the same depth of different branch holes in the coal seam floor at the excavation face, the types and concentrations of isotopes are analyzed and determined, and the diffusion effect of the grouting is checked; S6, branch hole optimization According to the isotope detection results, the average radius of the grouting fluid diffusion of each branch hole is calculated, the diffusion range and intersection area between holes are analyzed, and then the hole spacing is optimized, and the second open section branch hole construction is carried out according to the fault fissure grouting condition.

2. The method for identifying the grout diffusion range of long borehole grouting in coal mine floor according to claim 1, characterized in that: The isotope tracer in step S2 is selected from hydrogen and oxygen isotopes of water.

3. The method according to claim 2, characterized in that: The hydrogen and oxygen isotopes are selected from H2 16 O or H2 17 O or H2 18 O.

4. The method for identifying the grout diffusion range of long borehole grouting in coal floor according to claim 1, characterized in that: In step S3, different types of isotope tracers are selected for the grouting fluid in the branch hole, and different types of isotopes are mixed with the grouting fluid at the same proportion and uniformly injected into the first open section drilling hole.

5. The method for identifying the grout diffusion range of long borehole grouting in coal floor according to claim 1, characterized in that: In step S5, cores are drilled every 10m at different widths at the same depth of the floor, the types and concentrations of isotopes are determined, and the diffusion radius and intersection area between holes are analyzed.

6. The method for identifying the grout diffusion range of long borehole grouting in coal floor according to claim 1, characterized in that: In step S4, cores are drilled every 30m at different depths of the same branch hole, the types of isotopes are determined, and the fracture distribution and rock mass strength of the fault fracture zone are analyzed.

7. The method according to claim 5 or 6, characterized in that: The isotope determination uses a mass spectrometer.

8. The method for identifying the grout diffusion range of long borehole grouting in coal floor according to claim 1, characterized in that: The specific steps of the hole spacing optimization in step S6 are as follows: S61, from the lateral grouting expansion distance, the preset lateral grouting diffusion radius is X1m, and the directional branch hole plane spacing is 2X1m; S62, the actual diffusion radius of the first open section branch hole is X2m, if X2m>X1m, the expected diffusion distance value is exceeded, the grouting construction target is reached, at this time the hole spacing is optimized, and the hole spacing is increased from 2X1m to 2X2m; S63, the actual diffusion radius of the first open section branch hole is X3m, if X3mX1m, the expected diffusion distance value is not reached, and a supplementary hole is arranged between the first open section branch holes.

9. The method for identifying the grout diffusion range of long borehole grouting in coal floor according to claim 1, characterized in that: In the grouting process of step S3, the pump quantity, grouting fluid density, pump pressure, and hole mouth pressure are recorded every 30-40 minutes, and the cement consumption is calculated.

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