Rod hydraulic splitting machine solves the method of hanging roof at end of fully mechanized mining face in underground coal mine

Abstract

The application discloses a method for solving the roof suspension of the end of a fully mechanized coal mining face in a coal mine underground, and belongs to the field of coal mining, and the technical points are as follows: the method is designed according to the roof rock stratum lithology, occurrence condition, mechanical parameter, roadway support condition, roof weighting condition and working face engineering geological condition, drilling parameters and hydraulic fracturing parameters are designed, the fracturing section in the drilling is determined, the drilling is grouped, the fracturing rods are installed in the drilling in groups, and multi-section backward fracturing is carried out. Finally, the fracturing rods are taken out and the fracturing effect is observed, and the fracturing parameters are further optimized. According to the mechanical properties of the rock roof, the rock is fractured, the strength of the roof is reduced, and when the working face is mined to a certain position, the roof collapses in time, the suspension distance is reduced, the gas gathering condition is improved, the method is economic and practical, roof disasters and gas accidents are effectively prevented, and safety production is ensured.

Description

Technical Field

[0001] This invention relates to the field of coal mining, specifically to a method for solving the problem of roof overhang at the end of a fully mechanized coal mining face using a rod-type hydraulic rock splitter. Background Technology

[0002] Hard roofs are characterized by good integrity and high strength. After the coal seam is mined out, when the load on the end of the suspended roof is less than the breaking force of the immediate roof, the roof cannot collapse in time, forming a triangular suspended roof. The triangular suspended roof in the fully mechanized mining face is prone to causing gas accumulation in the goaf, forming a gas reservoir in the goaf. When the suspended roof reaches a certain extent, the roof of the end of the triangular area suddenly collapses, and the accumulated gas and other harmful gases rush out instantly, causing the gas at the end to exceed the limit. At the same time, during the end-end support shifting process, the top beam and tail beam of the support rub and collide with the exposed ends of the anchor cables of the end support, inevitably generating sparks, which may cause gas combustion or even explosion, resulting in incalculable losses. Therefore, efficient and rapid handling of large-area suspended roofs at the end is of great significance (see reference: Li Chengjie, Li Shuwei. Roof control technology for large-area suspended roofs at the end of fully mechanized mining faces [J]. Coal Science and Technology, 2008, 36(8):5.).

[0003] Currently, there are four main methods for dealing with overhanging roofs at the working face: ① Pre-splitting blasting. Pre-splitting blasting uses explosives to create cracks through shallow and deep holes, thereby weakening the hard rock strata directly above the working face. When these weakened hard roof strata enter the goaf, they collapse under their own weight and the pressure of the working face. Currently, this method is relatively effective, but blasting produces toxic and harmful gases such as CO, SO2, and NO. In the field, CO levels often exceed limits when blasting to deal with overhanging roofs at the working face, posing a significant safety hazard. ② Hydraulic fracturing. Hydraulic fracturing involves using high-pressure water to partially seal and fracture the roof in sections within boreholes before the working face is mined, thus disrupting the integrity of the roof. This method is widely used in fracturing and pressure relief in coal mining, but two problems were found in the underground end-roof treatment test: first, there are relatively many cracks in the end-roof, and the high-pressure water flows erratically during the hydraulic fracturing process; second, the direction of crack propagation in hydraulic fracturing is greatly affected by the ground stress. These factors combined result in a significant difference between the actual effect of hydraulic fracturing and the expected crack trend, making this method less effective in end-roof treatment. ③ Liquid carbon dioxide fracturing: This method is a high-pressure gas blasting technique that utilizes the rapid expansion of liquid carbon dioxide during heat absorption and vaporization to generate high pressure, causing the rock mass to break or crack. However, its power is relatively low, and it has high requirements for the roof, resulting in poor effectiveness. ④ Static expansion agent fracturing: The principle is to mix calcium oxide with water to form a slurry and inject it into the borehole. With the hydration reaction, the expansion and hardening effects occur simultaneously, forming new expanded products that can increase the solid phase volume by 2-3 times, generating expansion stress. However, the expansion stress is often insufficient to crack the rock, especially the hard top plate, so the effect is poor, and the efficiency is low due to the long working time.

[0004] Therefore, this patent proposes a method for handling overhanging rock at the end of the working face using a rod-type rock splitter. Specifically, a borehole is drilled in the advanced working face, and a hydraulic rock splitter is installed inside the borehole. The wedge assembly within the hydraulic rock splitter converts the longitudinal thrust into a transverse splitting force. The rock mass surrounding the borehole is subjected to tensile stress. When the tensile stress exceeds the tensile strength of the rock mass, cracks appear around the borehole. As the pressure increases, the cracks further expand, eventually leading to further cracking of the rock mass around the borehole. With the mining of the working face, the cracked end-face roof will collapse in time. Rod-type rock splitters are now widely used in mining engineering, construction engineering, demolition engineering, chemical and metallurgical production facilities, large-scale projects, and various emergency rescue fields, with a wide range of applications. They perform excellently in foundation excavation, rock mining, culvert excavation, and silent mining of various rocks. Summary of the Invention

[0005] The purpose of this invention is to provide a method for handling the suspended roof in the upper corner triangular area using a rod-type hydraulic rock splitter, so as to solve the problems of safety hazards, poor effect and low efficiency of the existing methods for controlling the suspended roof at the end of fully mechanized mining faces.

[0006] A method for solving the problem of roof overhang at the end of a fully mechanized coal mining face using a rod-type hydraulic rock splitter includes the following steps:

[0007] Step S1: Design the drilling and hydraulic fracturing schemes; determine the drilling parameters and hydraulic fracturing parameters.

[0008] Drilling parameters include: borehole spacing, borehole depth, and borehole row spacing;

[0009] Hydraulic fracturing parameters include: fracturing pressure and the positional distribution of the fracturing and non-fracturing sections within the borehole;

[0010] Step S2: Perform the construction according to step S1.

[0011] Furthermore, the method for determining the drilling parameters in step S1 is as follows:

[0012] The borehole spacing is 400–600 mm; (more accurately, the spacing of the top-cutting holes is 1.5–2 times the fracturing radius).

[0013] The drilling depth h is calculated using the following formula:

[0014]

[0015] M is the mining height, K P The rock fragmentation coefficient;

[0016] The method for determining the borehole spacing is as follows: When the daily advance distance of the working face is 4m to 6m, the boreholes are positioned 6m ahead of the working face, with a borehole spacing of 6000mm; when the daily advance distance of the working face is 6m to 8m, the boreholes are positioned 8m ahead of the working face, with a borehole spacing of 8000mm; when the daily advance distance of the working face is 8m to 10m, the boreholes are positioned 10m ahead of the working face, with a borehole spacing of 10000mm.

[0017] Furthermore, the method for determining the hydraulic fracturing parameters in step S1 is as follows:

[0018] For rocks with a uniaxial compressive strength of 80–100 MPa, the splitting pressure is set at 60–80 MPa; for rocks with a uniaxial compressive strength of 60–80 MPa, the splitting pressure is set at 40–60 MPa; and for rocks with a uniaxial compressive strength of 40–60 MPa, the splitting pressure is set at 20–40 MPa.

[0019] The location distribution of the splitting and non-splitting sections within the hydraulic splitting hole is as follows: sections with a uniaxial compressive strength of 40–100 MPa are designated as splitting sections with a length of 1 m; sections with a uniaxial compressive strength of less than 40 MPa are designated as non-splitting sections.

[0020] A method for solving the problem of roof overhang at the end of a fully mechanized coal mining face using a rod-type hydraulic rock splitter includes the following steps:

[0021] I. Investigate the general engineering geology of the site and determine the occurrence of roof rock through borehole inspection;

[0022] II. Design the drilling and hydraulic fracturing schemes; determine the drilling and hydraulic fracturing parameters;

[0023] Drilling parameters include: borehole spacing, borehole depth, and borehole row spacing;

[0024] Hydraulic fracturing parameters include: fracturing pressure and the positional distribution of the fracturing and non-fracturing sections within the borehole;

[0025] Ⅲ, Drill holes at a certain distance from the advanced working face;

[0026] IV. Group the boreholes and connect them to the oil lines;

[0027] V. Use a bar-type hydraulic rock splitter to perform backward splitting in the splitting sections arranged inside the hole, so that the fracture is connected.

[0028] VI. Observe the splitting effect. If necessary, use an enlarged shim to split the object again and adjust the splitting pressure.

[0029] Furthermore, the distance between the boreholes drilled in the advanced working face is:

[0030] When the daily advance distance of the working face is 4m to 6m, the drilling position is arranged 6m ahead of the working face;

[0031] When the daily advance distance of the working face is 6m to 8m, the drilling position is arranged at 8m ahead of the working face.

[0032] When the daily advance distance of the working face is 8m to 10m, the drilling position is arranged 10m ahead of the working face.

[0033] Further, observe the splitting effect. If necessary, use an enlarged shim to split the body again and adjust the splitting pressure: increase the splitting pressure by 5-20 MPa based on the drilling spacing obtained in step II.

[0034] A method for treating the overhanging roof in the upper corner triangular area using a bar-type hydraulic splitter includes the following steps:

[0035] Ⅰ. Conduct on-site investigation of the working face conditions with the roof suspended at the end, drill holes to inspect and test the physical and mechanical properties of the roof rock strata in the triangular area at the end: understand the engineering geological conditions and roof rock occurrence conditions such as the distance of the roof suspended at the end, the pressure situation of the working face, the lithology and thickness of the roof, the general situation of roadway support and its anchorage withdrawal, and the progress of working face mining.

[0036] II. Design of the roof-cutting drilling scheme and hydraulic fracturing scheme. Specifically: ① Roof-cutting drilling parameters mainly include drilling location, drilling depth, hole spacing, and hole row spacing. Specifically, the roof-cutting hole depth is determined based on the thickness of the hard roof strata and the coal seam mining height; the roof-cutting hole spacing is determined based on the fracturing radius obtained from individual borehole fracturing tests, and is set to be less than twice the fracturing radius; the roof-cutting hole row spacing is determined in conjunction with the roof lithology, the daily advance of the working face, and the drilling time; the roof-cutting hole angle is determined to be perpendicular to the roof based on the working principle and operation process of the fracturing rod. ② Hydraulic fracturing parameters mainly include fracturing pressure and the positional distribution of the fracturing and non-fracturing sections within the hole. Specifically, the fracturing pressure and positional distribution are determined based on the uniaxial compressive strength of the rock strata.

[0037] The location of the top-cutting hole is 8-15m ahead of the working face;

[0038] The top-cutting holes are arranged perpendicular to the roadway axis;

[0039] The spacing between the cut-out holes is 500–1000 mm;

[0040] The spacing between the cut-out holes is 5 to 15 m;

[0041] The depth of the cut hole is given by the formula To calculate; M represents the mining height, K P This represents the rock's fragmentation coefficient (ranging from 1.1 to 1.4).

[0042] The hydraulic splitting pressure is 40–100 MPa;

[0043] The location distribution of the splitting and non-splitting sections within the hydraulic splitting hole is as follows: sections with a uniaxial compressive strength of 40–100 MPa are designated as splitting sections with a length of 1 m; sections with a uniaxial compressive strength of less than 40 MPa are designated as non-splitting sections.

[0044] Ⅲ. On-site construction top cutting and drilling work must be carried out at least 10m away from the advanced support, the specific distance of which is determined by the daily advance distance.

[0045] IV. On-site grouping and oil line connection. Group the pumps into 2-3 groups based on factors such as tunnel width, borehole spacing, and pump station supply capacity, with one pump station in each group. Within each group, the same emulsion pump station is equipped with the number of fracturing rods according to the number of boreholes. The fracturing rods are then connected to the hydraulic pump station's inlet and outlet ports via high and low pressure oil pipes.

[0046] The same emulsion pump station can supply liquid to 4 to 6 splitting rods at the same time.

[0047] V. On-site splitting of the borehole from the inside out. Install a splitting rod in the splitting section furthest from the borehole opening and adjust it to the pre-split direction. Then, turn on the hydraulic pump station and push the manual valves on the pump station and power head to the working position. Set the splitting pressure according to the rock type, so that the splitting rod applies a load to the rock around the borehole, thereby creating and connecting the fractures between the boreholes. When the center wedge reaches its end, return the manual valves on the pump station and power head to their original positions, install the splitting gun at the next splitting position, and repeat the cycle.

[0048] The splitting direction of the splitting rod is perpendicular to the roadway axis;

[0049] The process allows for drilling ahead of the working face by a considerable distance, but the splitting operation must be carried out within the roadway support section.

[0050] VI. Observe the splitting effect. After a set of boreholes has been split, drill an observation hole between two adjacent split holes and use a borehole inspection instrument to observe the fracture formation. If there are few fractures, an enlarging shim can be used to split the body again. Based on the observation results and the overhang length of the end, optimize the splitting borehole parameters, such as adjusting the splitting pressure.

[0051] The further additional technical features of the above technical solution are as follows:

[0052] The uniaxial compressive strength of the hard roof rock is 40–100 MPa.

[0053] When the uniaxial compressive strength of the hard roof rock is 80-100 MPa, the splitting pressure is 60-80 MPa;

[0054] When the uniaxial compressive strength of the hard roof rock is 60-80 MPa, the splitting pressure is 40-60 MPa;

[0055] When the uniaxial compressive strength of the hard roof rock is 40-60 MPa, the splitting pressure is 20-40 MPa.

[0056] The method for treating large-area overhangs at the ends using a rod-type splitter provided by the present invention has the following advantages compared with existing methods:

[0057] (1) This invention relates to a method for controlling the roof at the end of a fully mechanized coal mining face, applicable to situations where the roadway roof fails to collapse in time during the mining process, resulting in a suspended roof. Specifically, it uses a rod-type hydraulic rock splitter to treat the roadway roof, weakening the roof rock and enabling the roof to collapse in time, thus shortening the suspended roof distance. This application describes for the first time the use of a rod-type hydraulic rock splitter to solve the problem of suspended roof at the end of a fully mechanized coal mining face. When applying this method, three new technical problems were encountered: how to determine the parameters of the roof-cutting borehole, how to determine the hydraulic splitting parameters, and how to adjust the parameters.

[0058] A. Determination of top-cut drilling parameters:

[0059] The method for determining the drilling parameters in step S1 is as follows:

[0060] The drilling spacing is 400–600 mm;

[0061] The drilling depth h is calculated using the following formula:

[0062]

[0063] M is the mining height, K P The rock fragmentation coefficient ranges from 1.1 to 1.4.

[0064] The method for determining the borehole spacing is as follows (the following guiding principles are original to this application): When the daily advance distance of the working face is 4m to 6m, the borehole position is arranged 6m ahead of the working face, and the borehole spacing is 6000mm; when the daily advance distance of the working face is 6m to 8m, the borehole position is arranged 8m ahead of the working face, and the borehole spacing is 8000mm; when the daily advance distance of the working face is 8m to 10m, the borehole position is arranged 10m ahead of the working face, and the borehole spacing is 10000mm.

[0065] The above principles have been verified through actual engineering projects. Failure to follow these guidelines will result in the following consequences: if the row spacing is too large, the problem of end overhang cannot be solved; if the row spacing is too small, the progress of drilling and splitting work will not match the progress of the working face, affecting the construction effect.

[0066] B. Determination of hydraulic splitting parameters.

[0067] Regarding the splitting pressure, this application, through actual engineering tests, draws the following conclusions:

[0068] For rocks with a uniaxial compressive strength of 80–100 MPa, the splitting pressure is set at 60–80 MPa; for rocks with a uniaxial compressive strength of 60–80 MPa, the splitting pressure is set at 40–60 MPa; and for rocks with a uniaxial compressive strength of 40–60 MPa, the splitting pressure is set at 20–40 MPa.

[0069] If the fracturing pressure is less than the set value, the boreholes will not be able to connect, affecting the construction results; if the fracturing pressure is greater than the set value, construction time and pump station capacity will be wasted.

[0070] Regarding the split and non-split sections, this application, through actual engineering testing, draws the following conclusions:

[0071] The location distribution of the splitting and non-splitting sections within the hydraulic splitting hole is as follows: sections with a uniaxial compressive strength of 40–100 MPa are designated as splitting sections with a length of 1 m; sections with a uniaxial compressive strength of less than 40 MPa are designated as non-splitting sections.

[0072] Determining whether a rock is split or not is difficult. If a rock with a uniaxial compressive strength of 30MPa to 40MPa is designated as a split section, it will waste construction time and increase the labor intensity of workers. If a rock with a uniaxial compressive strength of 40MPa to 60MPa is designated as a non-split section, it will cause the top slab to be difficult to collapse in time after splitting, and a cantilever structure will still be formed.

[0073] C. How to adjust the parameters.

[0074] Observe the splitting effect. If necessary, use an enlarged shim to split the body again and adjust the splitting pressure. The specific adjustment principle is to increase the splitting pressure by 5 to 20 MPa based on the drilling spacing obtained in step II.

[0075] (2) The splitting rod avoids the safety problems of blasting vibration in traditional construction methods, can achieve static controllability, generates a small impact, and can accurately position and control the splitting size.

[0076] (3) Fewer holes are required, reducing the labor intensity of workers and the time required for work;

[0077] (4) Drilling, splitting and other work can be carried out at locations far from the working face without affecting normal production at the working face;

[0078] (5) A hydraulic splitter can carry multiple guns, has a simple structure, is easy to operate, requires less personnel and equipment investment, is easy to maintain, has a long service life, and has significant economic benefits. Attached Figure Description

[0079] Figure 1 This is a schematic diagram of the installation method of the splitting rod inside the borehole according to the present invention.

[0080] Figure 2 This invention is a comprehensive columnar diagram of the drilling of the roof of a fully mechanized mining face in a certain mine.

[0081] Figure 3 This is a schematic diagram of temporary support for fully mechanized mining operations in a certain mine.

[0082] Figure 4 This is a cross-sectional view of the borehole layout of a certain mine according to the present invention.

[0083] Figure 5 This is a schematic diagram of the arrangement of the splitting section inside a borehole in a certain mine according to the present invention.

[0084] Figure 6This is a comprehensive columnar diagram of the drilling of the roof of a fully mechanized mining face in a certain mine.

[0085] Figure 7 This is a schematic diagram of temporary support for fully mechanized mining operations in a certain mine.

[0086] Figure 8 This is a cross-sectional view of the borehole layout of a certain mine according to the present invention.

[0087] Figure 9 This is a schematic diagram of the arrangement of the splitting section inside a borehole in a certain mine according to the present invention.

[0088] Figure 1-9 The annotations in the accompanying drawings are explained as follows:

[0089] 1. Split-hole area; 2. Pulse-jet drilling area; 3. Unsplit-hole area; 4. Drill hole; 5. Emulsion pump station; 6. Drilling rig; 7. Return airway; 8. Transport roadway; 9. High and low pressure oil pipes; 10. Advance support; 11. Siltstone; 12. Limestone; 13. Fine-grained sandstone; 14. Sandy mudstone; 15. Coal; 16. Split section; 17. Unsplit section; 18. Middle wedge; 19. Side wedge. Detailed Implementation

[0090] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and specific examples.

[0091] Implementation Method 1 (Baigou)

[0092] Step 1: Drill holes using an anchor drill rig and inspect them with a borehole inspection instrument to determine the lithology of the roof, the thickness and occurrence of each stratum, and to determine that the uniaxial compressive strength of the hard roof rock is 50 MPa. The borehole composite columnar section is shown below. Figure 2 As shown. On-site investigation determined that the daily advance of the working face was 7.2m, the mining height was 1.3m, and the width of the roadway was 4.4m.

[0093] Step 2: Design the drilling plan. Specifically: the borehole diameter is 50mm, the borehole depth is 7.7m, the borehole spacing is 500mm, the row spacing is 8000mm, and there are 8 boreholes per row. The boreholes closest to the sides are 450mm away from the sides. In the 6.7m thick fine-grained sandstone area, 6 splitting sections are constructed, with a splitting pressure of 45MPa. In the 4.4m thick sandy mudstone area, non-splitting sections are constructed. The working position 5.7m from the borehole opening is designated as the first splitting section, and the remaining splitting sections are set sequentially in a retreating manner.

[0094] Step 3: Drill the first row of holes 8m ahead of the pre-cut opening, and then drill the remaining holes according to the row spacing.

[0095] Step 4: Take the four holes closest to the solid coal as one group and the remaining four holes as another group, place the hydraulic pump station, install the splitting rod, and connect the splitting rod to the hydraulic pump station through high and low pressure oil pipes.

[0096] Step 5: Install the splitting rod on the first splitting section and adjust it to the pre-splitting direction. Adjust the splitting pressure to the preset value, then turn on the hydraulic pump station and push the manual valves on the pump station and power head to the working position to start splitting. Once the middle wedge has reached the end, return the manual valves on the pump station and power head to their original positions and move the splitting gun outward to the next splitting section, repeating the cycle.

[0097] Step Six: Observe the splitting effect. After inspection through the observation hole, the splitting effect was generally poor, with few cracks and poor continuity. An enlarged shim was added to the splitting rod and the hole spacing was adjusted to 400mm. The splitting was repeated, and the cracks were observed again. More cracks were developed and connected.

[0098] Implementation Method 2 (Grinding)

[0099] Step 1: Drill holes using an anchor drill rig and inspect them with a borehole inspection instrument to determine the lithology of the roof, the thickness and occurrence of each stratum, and to determine that the uniaxial compressive strength of the hard roof rock is 50 MPa. The borehole composite columnar section is shown below. Figure 6 As shown. On-site investigation determined that the daily advance of the working face was 4.8m, the mining height was 2.5m, and the width of the roadway was 4.6m.

[0100] Step Two, as follows Figure 6 As shown, boreholes are drilled away from the working face, with a diameter of 50mm, a depth of 8.4m, a spacing of 400mm, a row spacing of 6000mm, and 12 holes per row. Holes closest to the sides are 100mm from the sides. Three splitting sections are constructed in a 3.5m thick limestone area, with a splitting pressure of 70MPa. No splitting sections are constructed in a 1.8m thick siltstone area. In a 6.6m thick limestone area, two splitting sections are constructed starting from the side in contact with the siltstone, with a splitting pressure of 70MPa. The working position 7.4m from the borehole opening is designated as the first splitting section, and the remaining splitting sections are sequentially set backwards. The splitting section arrangement is as follows. Figure 7 As shown.

[0101] Step 3: Make a 10m advance cut and construct the first row of boreholes, and then construct the remaining boreholes according to the row spacing.

[0102] Step 4: Take 6 holes near the solid coal as one group and the remaining 6 holes as another group, place a hydraulic pump station, install a splitting rod, and connect the splitting rod to the hydraulic pump station through high and low pressure oil pipes.

[0103] Step 5: Install the splitting rod on the first splitting section and adjust it to the pre-splitting direction. Adjust the splitting pressure to the preset value, then turn on the hydraulic pump station and push the manual valves on the pump station and power head to the working position to start splitting. Once the middle wedge has reached the end, return the manual valves on the pump station and power head to their original positions and move the splitting gun outward to the next splitting section, repeating the cycle.

[0104] Step Six: Observe the splitting effect. Through the observation hole, the splitting effect is good, with numerous and interconnected cracks.

[0105] The above-described embodiments are preferred embodiments of the present invention and are only used to facilitate the illustration of the present invention. They are not intended to limit the present invention in any way. Any person skilled in the art who makes local modifications or alterations to the technical content disclosed in the present invention without departing from the scope of the technical features of the present invention shall still fall within the scope of the technical features of the present invention.

Claims

1. A method for solving the problem of hanging roof at the end of fully mechanized mining face in underground coal mine by using a rod hydraulic splitting machine, characterized in that: The application relates to a method for processing a hanging roof in a triangular area of an upper corner end head by using a rod type hydraulic splitting machine, drilling a hole in an advanced working face, installing a hydraulic splitting rod in the hole, converting longitudinal thrust into transverse splitting force by using a wedge block assembly in the hydraulic splitting rod, applying tensile stress to the broken rock around the hole, generating cracks around the hole when the tensile stress exceeds the tensile strength of the broken body, further expanding the cracks with the increasing pressure, and finally causing the rock around the hole to crack; The method comprises the following steps: I. investigating the engineering geological conditions of a site and determining the occurrence of roof rocks by drilling; II. designing a drilling scheme and a hydraulic splitting scheme; determining drilling parameters and hydraulic splitting parameters; The drilling parameters include drilling spacing, drilling depth and drilling row spacing; the drilling spacing is 400-600 mm; The drilling depth h is solved by the following formula: M is the mining height, K P is the rock dilatancy coefficient; The drilling row spacing is determined as follows: when the daily advancing distance of the working face is 4-6 m, the drilling position is arranged at a distance of 6 m in front of the working face, and the drilling row spacing is 6000 mm; when the daily advancing distance of the working face is 6-8 m, the drilling position is arranged at a distance of 8 m in front of the working face, and the drilling row spacing is 8000 mm; when the daily advancing distance of the working face is 8-10 m, the drilling position is arranged at a distance of 10 m in front of the working face, and the drilling row spacing is 10000 mm; The hydraulic splitting parameters include splitting pressure, position distribution of a splitting section and a non-splitting section in the hole; the splitting pressure is set to be 60-80 MPa for rocks with uniaxial compressive strength of 80-100 MPa; the splitting pressure is set to be 40-60 MPa for rocks with uniaxial compressive strength of 60-80 MPa; and the splitting pressure is set to be 20-40 MPa for rocks with uniaxial compressive strength of 40-60 MPa; The position distribution of the splitting section and the non-splitting section in the hydraulic splitting hole is that the splitting section is set to be 1 m long for rocks with uniaxial compressive strength of 40-100 MPa, and the non-splitting section is set for rocks with uniaxial compressive strength less than 40 MPa; III. drilling a hole at a certain distance in front of the working face; IV. grouping the holes and connecting oil lines; V. using a rod type hydraulic splitting machine to retreat splitting in the splitting section arranged in the hole, so that the cracks are penetrated; the holes are split from inside to outside in the field; the splitting rod is installed in the splitting section farthest from the hole mouth, and is adjusted to a pre-splitting direction, then a hydraulic pump station is started, a manual valve on the power head is pushed to a working gear, the splitting pressure is set according to the rock property, the splitting rod applies load to the rocks around the hole, so that cracks are generated between the holes and are penetrated; when the middle wedge block is in contact with the head, the pump station and the manual valve on the power head are reset, the splitting gun is installed to the next splitting position, and the cycle is repeated; the splitting direction of the splitting rod is perpendicular to the axis of the roadway; a hole is first drilled at a large distance in front of the working face, but the splitting operation must be in the supported section of the roadway; VI. observing the splitting effect, splitting the split body again by using an enlarged gasket according to the situation, and adjusting the splitting pressure: The splitting pressure is increased by 5-20 MPa on the basis of the drilling spacing obtained in step II.

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