Cutting angle and length accurate control method considering unevenness of tunnel face

Abstract

The invention relates to the technical field of slotting hole measurement, in particular to a slotting angle and length accurate control method considering unevenness of a tunnel face, which comprises the following steps: determining tunneling parameters of an expected slotting hole and an expected tunnel face horizontal line; the position of an actual slotting hole is obtained; the angle between the actual slotting hole and the actual tunnel face, the length from the actual slotting hole to the center line in the tunnel excavation direction and the slotting length of the actual slotting hole are obtained, the data are processed and analyzed through the data processing module, and then the slotting angle and length accurate control considering the unevenness of the tunnel face is achieved. By means of the method, cost reduction and efficiency increase of drilling and blasting method tunnel construction can be achieved, economic and social benefits are remarkable, and high application and popularization value is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of slot hole measurement, and in particular to a method for accurately controlling a slot angle and a length taking into account the unevenness of a tunnel face. Background Art

[0002] In tunnel excavation projects, trench blasting is an important link to ensure the quality and progress of tunnel excavation. The angle and depth of trench drilling directly affect the subsequent blasting effect.

[0003] However, in actual construction, the face may not be perpendicular to the tunnel edge. Due to the influence of the previous blasting, the face may be tilted, that is, the face is uneven. At this time, the original slot drilling scheme will result in the bottom of the slot holes on both sides being of different depths and angles, which will affect the blasting effect and excavation quality. At present, most of the existing slot blasting methods are based on the face perpendicular to the tunnel edge, that is, the face is considered to be a relative plane, without considering the unevenness of the face in practice. The adaptability and control accuracy of the uneven face are limited, which in turn affects the blasting effect. Summary of the invention

[0004] The present invention provides a method for accurately controlling the cutting angle and length of a groove taking into account the unevenness of a tunnel face, and accurately controls the cutting angle and length of the groove when the tunnel face is not perpendicular to the tunnel edge line.

[0005] The technical solution of the present invention is as follows: A method for accurately controlling the cutting angle and length taking into account the unevenness of the tunnel face, specifically comprising the following steps: S1. Based on the tunnel geological survey data and the geological prediction information of the actual tunnel face, the excavation area of ​​the actual tunnel face is parametrically designed to determine the excavation parameters of the expected excavation hole and the expected tunnel face horizontal line LY; The expected cutout hole is a wedge-shaped cutout, including an expected first cutout hole and an expected second cutout hole located in the same plane, and the two cutout holes are in the same horizontal plane; The excavation parameters of the expected slot hole and the expected tunnel face horizontal line LY include the expected slot length L TC , the angle between the expected slot hole axis and the expected tunnel face horizontal line LY is θ; S2. Install and level the bracket at a preset bracket distance L3 in front of the actual tunnel face, and the bracket is located on the center line LK of the tunnel excavation direction. Install the laser rangefinder and the data processing module on the bracket, and the top height is flush with the expected slot hole axis; S3. Obtain the intersection points M and N between the actual face and the tunnel sidelines LB on both sides through the laser rangefinder, and the distances L1 and L2 to the laser rangefinder, and perform dot positioning on M and N; obtain the horizontal distance L4 from the laser rangefinder to the tunnel sidelines LB on both sides, and perform dot positioning on the horizontal intersection points O1 and O2 from the laser rangefinder to the tunnel sidelines LB on both sides; S4, extending the axis of the expected slot hole and the intersection point with the actual tunnel face to obtain the position of the actual slot hole; S5. Input the excavation parameters of the expected slot hole and the expected tunnel face horizontal line LY, as well as the position of the actual slot hole, into the data processing module; obtain the angle between the actual slot hole and the actual tunnel face, the length of the actual slot hole from the center line LK of the tunnel excavation direction, and the actual slot length of the slot hole; The actual slotted hole is a wedge-shaped slotted hole, including an actual first slotted hole and an actual second slotted hole located in the same plane, and the two slotted holes are in the same horizontal plane.

[0006] In S5, the angle between the actual cut hole and the actual tunnel face is obtained using the following formula: x1=θ-γ=θ-arctan (L5 / 2L4), x2=θ+γ=θ+arctan(L5 / 2L4), Among them, x1 and x2 are the angles between the actual axes of the first and second slot holes and the actual tunnel face respectively; γ is the angle of ∠MNJ after drawing the vertical line NJ from N to the tunnel edge LB on the other side; the distance between M and N in the excavation direction is L5.

[0007] In S5, the intersection point of the tunnel excavation direction centerline LK and MN is G, and the length of the actual slot hole from the tunnel excavation direction centerline LK is the length of the line segment formed by the actual first slot hole opening and the actual second slot hole opening and G, which is obtained by the following formula: L 11 =[sin(90°-θ) / sin(θ-arctan(L2cosβ-L1cosα) / 2L4)]·[L TC sinθ+(L6 / 2)tanθ-L7], L 12 =[sin(90°-θ) / sin(θ+arctan(L2cosβ-L1cosα) / 2L4)]·[L TC sinθ+(L6 / 2)tanθ-L7], where L 11 and L 12They are the lengths of the actual first slot hole and the actual second slot hole opening from the center line LK of the tunnel excavation direction; the position of the laser rangefinder is point O, the angles between the ON and OM lines and the center line LK of the tunnel excavation direction are α and β; the expected distance from the bottom of the slot hole is L6; the intersection of MN and the center line LK of the tunnel excavation direction is G, and the length of OG is L7.

[0008] In S5, the actual slot length of the slot hole is obtained using the following formula: L TC1= [sin(90°+arctan(L2cosβ-L1cosα) / 2L4) / sin(θ-arctan(L2cosβ-L1cosα) / 2L4)]·[L TC sinθ+(L6 / 2)tanθ-L7]-(L6 / 2) / cosθ, L TC2= [sin(90°-arctan(L2cosβ-L1cosα) / 2L4) / sin(θ+arctan(L2cosβ-L1cosα) / 2L4)]·[L TC sinθ+(L6 / 2)tanθ-L7]-(L6 / 2) / cosθ, Among them, L TC1 and L TC2 are the actual slot lengths of the first slot hole and the actual second slot hole respectively.

[0009] The specific derivation steps of L7 length are: L7=GU=OG-OU, Where OG is the preset bracket distance L3 from the laser rangefinder to the tunnel face, and OU is the distance from the laser rangefinder to the expected tunnel face horizontal line LY.

[0010] A level bubble is provided in the bracket for leveling.

[0011] An angle scale is provided on the bracket.

[0012] The data processing module includes a processor and a memory. The processor is electrically connected to the memory, and a computer program is stored in the memory.

[0013] The laser rangefinder is electrically connected to the processor.

[0014] The processor executes the computer program stored in the memory.

[0015] Through the above technical solution, the present invention has the following beneficial effects: 1. The present invention can make the bottom of the cut hole at the same depth and angle, thus avoiding the situation where the tunnel face is tilted due to different tunneling sizes after blasting, and improving the blasting effect.

[0016] 2. The operation is simple and quick, with fewer measuring points to be positioned, thus improving construction efficiency.

[0017] 3. It has strong applicability. The distance between the laser rangefinder and the tunnel face can be selected at will and is not affected by the inclination of the tunnel face.

[0018] 4. It can effectively reduce the rework rate, reduce material waste and rework costs during the construction process, and shorten the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In the attached picture: Figure 1 It is a schematic diagram of the arrangement of calculation points of the present invention; Figure 2 It is a schematic diagram of calculating length of the present invention; Figure 3 A schematic diagram showing a comparison of the groove hole before and after the present invention; Figure 4 This is a flow chart of data collection and processing of the present invention; Figure 5 It is the overall flow chart of the present invention.

[0020] The components represented by the reference numerals in the figure are: 1. Laser rangefinder; 2. Bracket; 21. Level bubble; 22. Angle scale; 3. Data processing module; 31. Processor; 32. Memory; 4. Tunnel sideline LB; 5. Tunnel excavation direction centerline LK; 6. Expected tunnel face horizontal line LY; 7. Actual tunnel face horizontal line LS; 8. Actual tunnel face; 9. Expected slot hole; 10. Actual slot hole. DETAILED DESCRIPTION

[0021] Example 1 Reference Figure 5 The present invention provides a method for accurately controlling the cutting angle and length of the groove taking into account the unevenness of the tunnel face, and the specific steps include: S1. Based on the tunnel geological survey data and the geological prediction information of the actual tunnel face 8, the excavation area of ​​the actual tunnel face 8 is parametrically designed to determine the excavation parameters of the expected excavation hole 9 and the expected tunnel face horizontal line LY6.

[0022] The expected cutout hole 9 is a wedge-shaped cutout, including an expected first cutout hole and an expected second cutout hole located in the same plane, and the two cutout holes are in the same horizontal plane.

[0023] The excavation parameters of the expected slot hole 9 and the expected tunnel face horizontal line LY6 include the expected slot length L TC The angle between the expected axis of the slot hole 9 and the expected horizontal line LY6 of the tunnel face is θ.

[0024] Through parametric design, the position, length and angle of the expected notching hole 9 can be precisely controlled, thereby improving the accuracy and efficiency of notching.

[0025] Adapting to complex geological conditions, combining tunnel geological survey data and geological forecast information of the actual tunnel face 8, it can carry out adaptive design for different geological conditions to ensure the safety and effectiveness of trenching operations.

[0026] Reference Figure 4 , a level bubble 21 is provided in the support 2 for leveling. The level bubble 21 is used to ensure that the support 2 is in a horizontal state, which is the basis for accurate control of the slotting operation. Only when the support 2 is stable and horizontal, the subsequent measurement and control of the slotting angle and length can be accurate.

[0027] An angle scale 22 is provided on the support 2. The angle scale 22 allows the operator to directly read the angle between the marking point and the reference line, thereby ensuring accurate control of the groove angle. This is crucial to achieving the desired groove effect and controlling the tunnel excavation direction.

[0028] The data processing module 3 includes a processor 31 and a memory 32, wherein the processor 31 is electrically connected to the memory 32, and a computer program is stored in the memory 32. The laser rangefinder 1 is electrically connected to the processor 31. The data processing module 3 is the core of the solution, responsible for processing and analyzing data from the laser rangefinder 1, and executing the computer program stored in the memory 32. This configuration can process data efficiently and respond quickly to operating instructions, thereby achieving real-time and precise control of the angle and length of the groove.

[0029] The processor 31 executes the computer program stored in the memory 32 .

[0030] The stored computer program contains the algorithms and logic required to achieve precise control of the angle and length of the groove. These programs can guide the processor to perform the necessary calculations and control operations to ensure the accuracy and efficiency of the groove operation. The laser rangefinder 1 is used to measure the actual length and position information of the groove hole in real time and transmit these data to the processor 31. The processor 31 adjusts the groove operation based on these data to ensure precise control of the groove length. This real-time feedback mechanism improves the accuracy and reliability of the groove operation.

[0031] S2. Install and level the bracket 2 at a preset bracket distance L3 directly in front of the actual tunnel face 8, and the bracket 2 is located on the center line LK5 of the tunnel excavation direction. Install the laser rangefinder 1 and the data processing module 3 on the bracket 2, and the top height is flush with the axis of the expected slot hole 9.

[0032] Ensure that the position of the bracket 2 matches the actual needs of the slotting operation, and provide an accurate benchmark for the subsequent slotting angle and length control. The leveling operation of the bracket 2 ensures its stability during the operation, which is crucial for the stable operation of the laser rangefinder 1 and the data processing module 3, and helps to reduce measurement errors and control deviations. The data processing module 3 is directly connected to the laser rangefinder 1, and can receive and process measurement data in real time, so as to quickly adjust the slotting operation parameters and improve the operation efficiency and accuracy.

[0033] S3. Obtain the intersection points M and N of the actual tunnel face 8 and the tunnel sidelines LB4 on both sides through the laser rangefinder 1, and the distances L1 and L2 to the laser rangefinder 1, and perform dot positioning on M and N; obtain the horizontal distance L4 from the laser rangefinder to the tunnel sidelines LB4 on both sides, and perform dot positioning on the horizontal intersection points O1 and O2 from the laser rangefinder to the tunnel sidelines LB4 on both sides.

[0034] The laser rangefinder 1 can measure distances with high precision, so the intersection points M and N are located very accurately. This is crucial for the subsequent determination of the position and angle of the slotting hole, which helps to ensure that the slotting operation is carried out in the correct direction. The line segment O1O2 is perpendicular to the tunnel sideline LB4. The dot positioning allows the intersection points M and N to be clearly marked at the tunnel site, making it easier for operators to intuitively understand the position and angle requirements of the slotting hole. The positioning points O1 and O2 can be used as reference points for subsequent measurement and verification to ensure that the slotting operation meets the design requirements.

[0035] S4. Extend the axis of the expected slot hole 9 and its intersection with the actual tunnel face 8 to obtain the position of the actual slot hole 10.

[0036] In order to ensure that the depth and angle of the slot hole drilling are the same even when the actual tunnel face 8 is inclined, the relative position of the actual slot hole 10 needs to remain unchanged, the point on the side that needs to be extended is the opening position of the slot hole on that side, and only that side needs to be extended and the other side shortened.

[0037] S5. Input the excavation parameters of the expected slot hole 9 and the expected horizontal line LY6 of the tunnel face, as well as the position of the actual slot hole 10, into the data processing module 3; obtain the angle between the actual slot hole 10 and the actual tunnel face 8, the length of the actual slot hole 10 from the center line LK5 of the tunnel excavation direction, and the actual slot length of the slot hole 10.

[0038] refer to Figure 3, the specific reasoning process of data processing module 3 includes: Draw a horizontal line at N, and the intersection point with the other side tunnel edge line LB4 is J. NJ intersects with OM at point H, and intersects with the tunnel excavation direction center line LK5 at point R. Let the angle of ∠MNJ be γ, and the angle of ∠NMH be δ, then the length of MG L5 = MO2-NO1 = L2cosβ-L1cosα; From tanγ=MJ / NJ=L5 / 2L4, we can conclude that γ=arctan(L5 / 2L4); The intersection points of the expected horizontal line LY6 of the tunnel face and the tunnel sideline LB4 are C and D. The expected horizontal line LY6 of the tunnel face is perpendicular to the tunnel sideline LB4. The expected slot holes 9 are EP1 and FQ1, and the expected length is L. TC , with an angle of θ, and in a symmetrical state, where the distance between the bottom of the hole E and F is L6, and EF intersects the center line LK5 of the tunnel excavation direction at point T, and the line segments EP1 and FQ1 are extended to intersect at point W; Since the actual horizontal line LS7 of the tunnel face is not perpendicular to the tunnel sideline LB4 but is inclined, the actual cut holes 10 should be set as EP2 and FQ2, and their lengths are L TC1 , L TC2 ; P2 and Q2 are the intersection points of the extended lines of EP1 and FQ1 and NM respectively. A perpendicular line through P2 is drawn to intersect the tunnel side line LB4 at point S. Then the angle ∠EP2M is ∠EP2S-∠MP2S=θ-γ. Similarly, the angle ∠FQ2N is =θ+γ. Combination Figures 1 to 3 , draw a perpendicular line through P1 to the tunnel excavation direction center line LK5 and intersect it at point U, where the length L7 of line segment GU is a known value, which is determined by the position of the expected horizontal line LY6 of the tunnel face; since ∠WEF=∠WP2S, the length L8 of line segment WT is (L6 / 2)tanθ, and the length L9 of line segment WE is (L6 / 2) / cosθ, then from △WP1U, the length of line segment WU is L 10 Length: L TC sinθ+(L6 / 2)tanθ,WG=WU-GU=L 10 -L7; In △P2WG, the angle of ∠P2WG is 90°-θ, the angle of ∠WGP2 is 90°+γ, and the length of line segment P2G is L 11 , the length of line segment EP2 is L TC1 , according to the sine theorem: sin(θ-γ) / (L 10 -L7) = sin(90°-θ) / L 11 = sin(90°+γ) / (L TC1 +L9), From this we can get: L11 =[sin(90°-θ) / sin(θ-γ)]·(L 10 -L7), L TC1= [sin(90°+γ) / sin(θ-γ)]·(L 10 -L7)-L9; Similarly, in △Q2WG, let the length of line segment Q2G be L 11 , from the sine theorem we can get: sin(θ+γ) / (L 10 -L7) = sin(90°-θ) / L 12 = sin(90°-γ) / (L TC2 +L9), From this we can get: L 12 =[sin(90°-θ) / sin(θ+γ)]·(L 10 -L7), L TC2 =[sin(90°-γ) / sin(θ+γ)]·(L 10 -L7)-L9; The actual cutout hole 10 is a wedge-shaped cutout, including an actual first cutout hole and an actual second cutout hole located in the same plane, and the two cutout holes are in the same horizontal plane.

[0039] The angle between the actual cut hole 10 and the actual tunnel face 8 is obtained using the following formula: x1=θ-γ=θ-arctan (L5 / 2L4), x2=θ+γ=θ+arctan(L5 / 2L4), Among them, x1 and x2 are the angles between the actual first slot hole and the actual second slot hole axis and the actual tunnel face 8 respectively; γ is the angle ∠MNJ after drawing the vertical line NJ from N to the other side tunnel edge LB4; the distance between M and N in the excavation direction is L5.

[0040] The intersection point of the tunnel excavation direction center line LK5 and MN is G. The length of the actual slot hole 10 from the tunnel excavation direction center line LK5 is the length of the line segment formed by the actual first slot hole opening and the actual second slot hole opening and G, which is obtained by the following formula: L 11 =[sin(90°-θ) / sin(θ-arctan(L2cosβ-L1cosα) / 2L4)]·[L TC sinθ+(L6 / 2)tanθ-L7], L 12=[sin(90°-θ) / sin(θ+arctan(L2cosβ-L1cosα) / 2L4)]·[L TC sinθ+(L6 / 2)tanθ-L7], Among them, L 11 and L 12 They are the lengths of the actual first slot hole and the actual second slot hole from the center line LK5 of the tunnel excavation direction; the position of the laser rangefinder 1 is point O, the angles between the ON and OM lines and the center line LK5 of the tunnel excavation direction are α and β; the expected distance from the bottom of the slot hole 9 is L6; the intersection of MN and the center line LK5 of the tunnel excavation direction is G, and the length of OG is L7.

[0041] The specific derivation steps of L7 length are: L7=GU=OG-OU, Wherein OG is the preset bracket distance L3 from the laser rangefinder 1 to the tunnel face, and OU is the distance from the laser rangefinder 1 to the expected tunnel face horizontal line LY6.

[0042] The actual slotting hole 10 slotting length is obtained using the following formula: L TC1= [sin(90°+arctan(L2cosβ-L1cosα) / 2L4) / sin(θ-arctan(L2cosβ-L1cosα) / 2L4)]·[L TC sinθ+(L6 / 2)tanθ-L7]-(L6 / 2) / cosθ, L TC2= [sin(90°-arctan(L2cosβ-L1cosα) / 2L4) / sin(θ+arctan(L2cosβ-L1cosα) / 2L4)]·[L TC sinθ+(L6 / 2)tanθ-L7]-(L6 / 2) / cosθ, Among them, L TC1 and L TC2 are the actual slot lengths of the first slot hole and the actual second slot hole respectively.

[0043] The bottom of the actual slot hole 10 is at the same depth, and the axis of the actual slot hole 10 is at the same angle as the expected tunnel face, which avoids the situation where the actual tunnel face 8 continues to be different in excavation size after blasting, causing the actual tunnel face 8 to tilt, thereby improving the blasting effect.

Claims

1. A method for accurately controlling the cutting angle and length taking into account the unevenness of the tunnel face, characterized in that: The specific steps include: S1, based on the tunnel geological survey data and the geological prediction information of the actual tunnel face (8), a parametric design is performed on the groove area of ​​the actual tunnel face (8), and the excavation parameters of the expected groove hole (9) and the expected tunnel face horizontal line LY (6) are determined; The expected groove hole (9) is a wedge-shaped groove, comprising an expected first groove hole and an expected second groove hole located in the same plane, and the two groove holes are located in the same horizontal plane; The excavation parameters of the expected cut hole (9) and the expected face level LY (6) include the expected cut length L TC , the angle between the axis of the expected cut hole (9) and the expected horizontal line LY (6) of the tunnel face is θ; S2. Install the support (2) and level it at a preset support distance L3 directly in front of the actual tunnel face (8), and position the support (2) on the center line LK (5) of the tunnel excavation direction. Install the laser rangefinder (1) and the data processing module (3) on the support (2), and make the top height flush with the axis of the expected slot hole (9); S3, using the laser rangefinder (1), obtain the intersection points M and N between the actual tunnel face (8) and the tunnel sidelines LB (4) on both sides, and the distances L1 and L2 to the laser rangefinder (1), and perform dot positioning on M and N; obtain the horizontal distance L4 from the laser rangefinder to the tunnel sidelines LB (4) on both sides, and perform dot positioning on the horizontal intersection points O1 and O2 from the laser rangefinder to the tunnel sidelines LB (4) on both sides; S4, extending the axis of the expected slot hole (9) to the intersection point with the actual tunnel face (8) to obtain the position of the actual slot hole (10); S5, inputting the excavation parameters of the expected slot hole (9) and the expected tunnel face horizontal line LY (6), as well as the position of the actual slot hole (10), into the data processing module (3); obtaining the angle between the actual slot hole (10) and the actual tunnel face (8), the length of the actual slot hole (10) from the tunnel excavation direction center line LK (5), and the slot length of the actual slot hole (10); The actual groove hole (10) is a wedge-shaped groove, comprising an actual first groove hole and an actual second groove hole located in the same plane, and the two groove holes are located in the same horizontal plane.

2. The method according to claim 1, characterized in that In S5, the angle between the actual cut hole (10) and the actual tunnel face (8) is obtained using the following formula: x1=θ-γ=θ-arctan (L5 / 2L4), x2=θ+γ=θ+arctan(L5 / 2L4), Wherein, x1 and x2 are the angles between the axes of the actual first and second slot holes and the actual tunnel face (8), respectively; γ is the angle ∠MNJ after drawing the vertical line NJ from N to the other side tunnel edge line LB (4); and the distance between M and N in the excavation direction is L5.

3. The method according to claim 2, characterized in that In S5, the intersection point of the tunnel excavation direction center line LK (5) and MN is G, and the length of the actual slot hole (10) from the tunnel excavation direction center line LK (5) is the length of the line segment formed by the actual first slot hole opening and the actual second slot hole opening and G, respectively, which is obtained by the following formula: <h2 style=";text-align:left;direction:ltr">L<h2 style=";text-align:left;direction:ltr"> 11 <h2 style=";text-align:left;direction:ltr"> =[sin(90°-θ) / sin(θ-arctan(L2cosβ-L1cosα) / 2L4)]·[L<h2 style=";text-align:left;direction:ltr"> TC <h2 style=";text-align:left;direction:ltr"> sinθ+(L6 / 2)tanθ-L7], <h2 style=";text-align:left;direction:ltr">L<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> =[sin(90°-θ) / sin(θ+arctan(L2cosβ-L1cosα) / 2L4)]·[L<h2 style=";text-align:left;direction:ltr"> TC <h2 style=";text-align:left;direction:ltr"> sinθ+(L6 / 2)tanθ-L7], Among them, L 11 and L 12 are the lengths of the actual first slot hole and the actual second slot hole opening from the tunnel excavation direction center line LK (5) respectively; the position of the laser rangefinder (1) is point O, the angles between the ON and OM lines and the tunnel excavation direction center line LK (5) are α and β; the expected distance from the bottom of the slot hole (9) is L6; the intersection point of MN and the tunnel excavation direction center line LK (5) is G, and the length of OG is L7.

4. The method according to claim 3, characterized in that In S5, the actual cutting length of the cutting hole (10) is obtained by the following formula: <h2 style=";text-align:left;direction:ltr">L<h2 style=";text-align:left;direction:ltr"> TC1= <h2 style=";text-align:left;direction:ltr"> [sin(90°+arctan(L2cosβ-L1cosα) / 2L4) / sin(θ-arctan(L2cosβ-L1cosα) / 2L4)]·[L<h2 style=";text-align:left;direction:ltr"> TC <h2 style=";text-align:left;direction:ltr"> sinθ+(L6 / 2)tanθ-L7]-(L6 / 2) / cosθ, <h2 style=";text-align:left;direction:ltr">L<h2 style=";text-align:left;direction:ltr"> TC2= <h2 style=";text-align:left;direction:ltr"> [sin(90°-arctan(L2cosβ-L1cosα) / 2L4) / sin(θ+arctan(L2cosβ-L1cosα) / 2L4)]·[L<h2 style=";text-align:left;direction:ltr"> TC <h2 style=";text-align:left;direction:ltr"> sinθ+(L6 / 2)tanθ-L7]-(L6 / 2) / cosθ, Among them, L TC1 and L TC2 are the actual slot lengths of the first slot hole and the actual second slot hole respectively.

5. The method according to claim 3, characterized in that: The specific derivation steps of L7 length are: L7=GU=OG-OU, Wherein OG is the preset support distance L3 from the laser rangefinder (1) to the tunnel face, and OU is the distance from the laser rangefinder (1) to the expected tunnel face horizontal line LY (6).

6. The method according to claim 1, characterized in that The support (2) is provided with a level bubble (21) for leveling.

7. The method according to claim 1, characterized in that The bracket (2) is provided with an angle scale (22).

8. The method according to claim 1, characterized in that The data processing module (3) comprises a processor (31) and a memory (32); the processor (31) is electrically connected to the memory (32); and a computer program is stored in the memory (32).

9. The method according to claim 1, characterized in that: The laser rangefinder (1) is electrically connected to the processor (31).

10. The method according to claim 8, characterized in that The processor (31) executes the computer program stored in the memory (32).

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