A method for accurately positioning the angle of shaped charge blasting based on tunnel section contour line

Abstract

The present application relates to the field of tunnel blasting construction, in particular to a method for accurately positioning the angle of shaped charge blasting based on the profile line of a tunnel section, comprising: dividing the profile line into multiple parts according to the actual situation, expressing each part in a function form, determining the function domain and value domain; regarding the peripheral hole as a certain point on the function, determining the position of the peripheral hole according to the parameters such as penetration length, maximum overbreak value and average overbreak value, and regarding the energy-gathering cutting direction as the tangent direction of the point; calculating the tangent slope of the point, converting the slope into an angle, thereby achieving accurate positioning of the angle of shaped charge blasting, and further ensuring the subsequent blasting construction effect.

Description

Technical Field

[0001] This invention belongs to the field of tunnel construction technology, specifically relating to a method for precise positioning of shaped charge blasting angles based on the tunnel cross-sectional contour lines. Background Technology

[0002] Currently, shaped charge blasting, as an advanced blasting technology, has made significant progress in tunnel construction and other fields in recent years. In terms of application scope, shaped charge blasting has been widely used in smooth blasting of railway, highway, and subway tunnels, as well as in mining and coal mine roof cutting. Its role is particularly prominent in tunnel construction, effectively solving problems faced by traditional blasting techniques such as severe over- and under-excavation, significant disturbance to the surrounding rock, and low construction efficiency.

[0003] Against this backdrop, the precise positioning of the shaped charge device is particularly important: the core function of the shaped charge device is to concentrate the detonation energy into a directional high-kinetic-energy jet through a shaped charge groove (such as a V-shaped or arc-shaped groove), and the installation angle directly changes the relative position of the jet's "axis of action" and the rock. If the cracks cut by the jet formed by the shaped charge device in the peripheral holes can be precisely connected, a smooth tunnel excavation profile can be formed, which can effectively control over-excavation and under-excavation. However, at present, the positioning of the blasting angle of the shaped charge device is still determined manually based on historical construction experience, which makes the shaped charge blasting work far from achieving the ideal effect. Summary of the Invention

[0004] To address the technical problems mentioned above, this invention provides a method for precise positioning of shaped charge blasting angles based on tunnel cross-sectional contour lines.

[0005] The technical solution of the present invention is as follows: This invention provides a method for precise positioning of shaped charge blasting angles based on tunnel cross-sectional contour lines. The tunnel cross-sectional contour lines include the excavation cross-sectional contour line and the inner contour line of the lining after internal support. The positioning method specifically includes the following steps: S1. Construct a piecewise function expression based on the inner contour line of the lining; S2. Determine the set hole depth for a single hole on the outline of the excavation section, and the blasting penetration length of the crack under the set charge amount. S3. Based on the data determined in steps S1 and S2, calculate the number of peripheral holes to be opened on the outline of the excavation section, and the angle at which the energy-concentrating device of each peripheral hole should deflect. S4. Based on the data determined in step S3, perform wire-connected blasting; S5. Inspect and evaluate the blasting effect.

[0006] The method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines, as described above, includes step S1 as follows: S1.1 Determine the relative position; S1.1.1 Divide the inner contour line of the lining into multiple segments of the first contour line, wherein the multiple segments of the first contour line contain multiple segments of the first arc contour line that are arc-shaped. The excavation section outline (1) includes multiple arc-shaped second arc-shaped outlines that are concentric with the first arc-shaped outline. S1.1.2. Taking the center O of one segment of the second arc contour line that needs to be calculated as the reference point, the centers O of multiple segments of the second arc contour line are... n Represented using coordinates; S1.2, Determine the origin of the coordinate system; Establish a Cartesian coordinate system XOY, and represent the coordinates of the centers of the multiple second arc contour lines on the XOY plane; S1.3 represents the cross-sectional outline; The multiple segments of the second arc contour are represented in the form of functions; S1.4 Determine the range and domain; Based on the construction drawings of the cross-sectional contour lines, calculate and determine the range and domain of the functions corresponding to multiple segments of the second arc contour lines.

[0007] As a preferred embodiment, to facilitate the functional expression of the arc contour line, in step S1.2, the inner contour line of the lining is an axisymmetric figure, and the origin of the plane rectangular coordinate system XOY is located on the axis of symmetry.

[0008] As a further preferred embodiment, in step S1.2, the second arc-shaped profile includes an arch profile that opens downward and is arc-shaped, and an inverted arch profile that opens upward and is arc-shaped, with the origin of the plane rectangular coordinate system XOY being the center O1 of the arch profile.

[0009] As described above, in the method for precise positioning of the shaped charge blasting angle based on the tunnel cross-section contour, the blasting penetration length in step S2 is determined based on hydrological and geological survey data before construction, as well as blasting scheme design procedures, and through engineering experience summary, numerical simulation, and similar simulation experiments.

[0010] Specifically, in step S2, typically: For Class I and II surrounding rock, the penetration length is 30-90 cm when the charge is 300-400 g / m. For Class III and IV surrounding rock, the penetration length is 20-70 cm when the charge is 200-300 g / m. For Class V and VI surrounding rock, the penetration length is 10-30cm when the charge is 100-200g / m.

[0011] As described above, in the method for precise positioning of the shaped charge blasting angle based on the tunnel cross-section contour, the number of peripheral holes and the deflection angle of the shaped charge device in step S3 are calculated based on the over-excavation limit of the tunnel face contour, the length of the penetration crack, and the cross-section contour.

[0012] Specifically, in step S3, the method for determining the number of peripheral holes is as follows: AS3.1 Determine the maximum over-excavation value and the average linear over-excavation value according to the over-excavation limit regulations; AS3.2. Based on existing research data and engineering experience, and in combination with different lithology and charge parameters, determine the penetration fracture length; AS3.3. Based on the data obtained in steps AS3.1 and AS3.2, calculate the number and location of the surrounding holes and convert them into points on the outline of the excavation section in the coordinate system.

[0013] In step S3, regarding the positioning method of the deflection angle of the energy focusing device, it is specifically as follows: BS3.1 Treat the blast hole as a point on the excavation section outline and calculate the tangent slope at that point; BS3.2 converts the slope into an angle to achieve precise positioning of the energy-concentrating cutting angle.

[0014] The method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines as described above is characterized in that step S5 specifically comprises: The blasting effect is evaluated based on the quantitative indicators of half-hole ratio, maximum over-excavation, and average linear over-excavation specified in the prescribed working face profile. If there are results that do not meet the standards, the data involved in steps S2-S4 should be adjusted for the next blasting.

[0015] The beneficial effects of this invention are as follows: (1) By establishing an accurate circular curve function model, each blast hole on the cross-sectional contour line is converted into a coordinate point, and the tangent slope of the point is accurately calculated and finally converted into the blasting angle. This eliminates human experience and visual errors and improves the accuracy of blasting angle positioning. (2) After establishing the coordinate system and the function model of the cross-sectional contour line through steps S1-S4, the angle calculation of all borehole points on the entire cross-sectional contour line can be completed in batches with the help of computer programs. Only the design parameters need to be input to quickly generate a table of accurate angle data for all boreholes, which greatly improves the efficiency of the preliminary preparation work. (3) By calculating the tangent slope of the blast hole through differentiation, it is ensured that the direction of the energy-concentrating groove of each peripheral blast hole is strictly perpendicular to the tangent direction of the outline of that point, so that the explosive energy can be accurately released along the excavation outline, forming a smooth blasting surface, reducing the disturbance to the surrounding rock, effectively controlling over-excavation and under-excavation, and improving the construction quality. (4) By establishing coordinate systems and function models in different regions, it can flexibly deal with complex geometric contours and has a wide range of applications. Attached Figure Description

[0016] The solutions and advantages of this application will become clear to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention.

[0017] In the attached diagram: Figure 1 This is a design drawing of the tunnel cross-section outline in the embodiment; Figure 2 This is a schematic diagram of the tunnel cross-section outline in the embodiment; Figure 3 This is a schematic diagram of the energy-concentrating device in the embodiment; Figure 4 This is a schematic diagram of the installation of the energy-concentrating device in the embodiment; Figure 5 for Figure 4 A magnified view showing the relative positional relationship between the penetration crack and the cross-sectional outline at position A in the middle; Figure 6 This is a schematic diagram showing the included angle of the energy-concentrating device in the embodiment; The components represented by the various reference numerals in the diagram are: 1. Excavation section outline; 2. Lining inner outline; 3. Energy focusing device; 31. Outer shell; 32. Energy focusing trough; 4. Penetration crack. Detailed Implementation

[0018] To further understand the content of this invention, the invention will be described in detail below with reference to the embodiments and accompanying drawings.

[0019] Example: This embodiment provides a method for precise positioning of the shaped charge blasting angle based on the tunnel cross-section contour line. (See also...) Figures 1-6 The tunnel's cross-sectional outline includes the excavation cross-sectional outline 1 and the inner outline 2 of the lining after internal support of the excavation cross-sectional outline 1. The positioning method specifically includes the following steps: S1. Construct a piecewise function expression based on the inner contour line 2 of the lining; S1.1 Determine the relative position; S1.1.1 Divide the inner contour line 2 of the lining into multiple segments of the first contour line, wherein the multiple segments of the first contour line contain multiple segments of the first arc contour line in an arc shape. The excavation section outline 1 includes multiple arc-shaped second arc-shaped outlines that are concentric with the first arc-shaped outline. Specifically, the excavation section outline 1 includes the arch outline, the invert arch outline, the vertical sections on both sides, and the flat bottom section. Among them, the second arc-shaped outline of multiple sections is the arch outline with an opening downward and an arc shape, and the invert arch outline with an opening upward and an arc shape. S1.1.2. Taking the center O of one segment of the second arc contour line that needs to be calculated as the reference point, the centers O of multiple segments of the second arc contour line are... n Represented using coordinates; Specifically, in this embodiment, the center O1 of the arch outline is taken as the reference point, and the coordinates corresponding to the center O3 of the invert arch outline are (0, 1190), where the data 1190 is directly obtained from the construction drawings of the cross-sectional outline in this embodiment. S1.2, Determine the origin of the coordinate system; Establish a Cartesian coordinate system XOY, and represent the coordinates of the centers of the multiple second arc contour lines on the XOY plane; As a preferred embodiment of this example, in order to facilitate the functional expression of the second arc-shaped contour line, in step S1.2, the inner contour line 2 of the lining is an axisymmetric figure, and the origin of the plane rectangular coordinate system XOY is located on the axis of symmetry. As a further preferred embodiment, the origin of the plane rectangular coordinate system XOY is the center O1 of the arch contour line. That is, in this embodiment, the reference point O1 is used as the origin XY1, the axis of symmetry of the inner contour line 2 of the lining is used as the y-axis of the coordinate system, and the x-axis is perpendicular to the y-axis. The plane rectangular coordinate system XOY1 is established, and the coordinate positions of O1 and O3 remain unchanged. S1.3 represents the cross-sectional outline; The arch profile and invert arch profile are represented as functions. Specifically: Arch outline: x 2 +y 2 =(540+60) 2 Data 540 is obtained directly from the construction drawings of the cross-sectional outline in this embodiment, and data 60 is the lining support thickness, that is, the radius difference between the arch outline and its corresponding first arc outline, and the radius difference between the invert arch outline and its corresponding first arc outline. Inverted arch outline: x 2 +(y-1190) 2 =(1500+60) 2 ; S1.4 Determine the range and domain; Based on the construction drawings of the cross-sectional contour lines, calculate and determine the range and domain of the functions corresponding to multiple segments of the second arc contour lines; Specifically, in this embodiment, the angle corresponding to the arch contour line is 180°, and the function of the arch contour line can be written as: x 2 +y 2 =(540+60) 2 x∈[-600, 600], y∈[0, 600] Then, with the center O3 of the arch outline as the origin XY2, the symmetry axis of the inner outline 2 of the lining as the y-axis of the coordinate system, and the x-axis perpendicular to the y-axis, a plane rectangular coordinate system XOY2 is established. The coordinates expressed in XOY2 in the above formula can be transformed into XOY1 as (-482.07, -293.65); The angle corresponding to the invert arch profile is 36°, and it is symmetric about the y-axis of XOY1. The invert arch profile function can be written as: x 2 +(y-1190) 2 =(1500+60) 2 x∈[-482.07,482.07],y∈[-370,-293.65] S2. Determine the set hole depth of a single hole on the excavation section outline 1, and the blasting penetration length of the penetration crack 4 under the set charge amount. The blasting penetration length is determined based on hydrological and geological survey data before construction, as well as blasting scheme design regulations, and through engineering experience summaries, numerical simulations, and similar simulation experiments. generally: For Class I and II surrounding rock, the penetration length is 30-90 cm when the charge is 300-400 g / m. For Class III and IV surrounding rock, the penetration length is 20-70 cm when the charge is 200-300 g / m. For Class V and VI surrounding rock, the penetration length is 10-30 cm when the charge is 100-200 g / m. S3. Based on the data determined in steps S1 and S2, calculate the number of peripheral holes to be opened on the excavation section outline 1, and the angle at which the energy-concentrating device 3 of each peripheral hole should be deflected, wherein the energy-concentrating device 3 includes the outer shell 31 and the energy-concentrating groove 32 inside it. Specifically, the number of peripheral holes and the deflection angle of the energy-concentrating device 3 are calculated based on the over-excavation limit of the face profile, the length of the penetration crack 4, and the cross-sectional profile. Specifically, the method for determining the number of peripheral holes is as follows: AS3.1 Determine the maximum over-excavation value and the average linear over-excavation value according to the over-excavation limit regulations; AS3.2. Based on existing research data and engineering experience, and in combination with different lithology and charge parameters, determine the length of the penetration fracture 4. AS3.3. Based on the data obtained in steps AS3.1 and AS3.2, calculate the number and location of the surrounding holes and convert them into points on the excavation section outline 1 in the coordinate system. Regarding the positioning method of the deflection angle of the energy focusing device 3, it is specifically as follows: BS3.1 Treat the blast hole as a point on the excavation section outline 1, and calculate the tangent slope at that point; BS3.2 converts the slope into an angle to achieve precise positioning of the energy-concentrating cutting angle; In this embodiment, taking railway tunnel blasting construction as an example, according to relevant regulations, for drill-and-blast construction, the average linear over-excavation value should be ≤10~15cm, and the maximum over-excavation value should be ≤25cm. In this embodiment, the average linear over-excavation value is taken as 12cm, and the maximum over-excavation value is 20cm. Taking the midpoint of the arch contour line as the first peripheral hole and using it as the starting point for calculation, in the coordinate system... The middle is marked as a dot. (0, 600), penetration length is 50cm, penetration direction is horizontal; Since the inner contour line 2 of the lining in this embodiment is an axisymmetric figure, and the axis of symmetry is the coordinate system... Since the Y-axis is the boundary, we only need to calculate the positive direction of the X-axis. The coordinates of the endpoint of the penetration along the positive X-axis are: (50, 600); With point Using coordinates and the arch contour function as conditions, calculate the next peripheral hole. The location is calculated as follows: point ( Located on the circle: and The line segment formed lies on the tangent to the circle, and the point of tangency is... Therefore: Right now After simplification After substituting into the equation of the arch contour line and simplifying, we get The coordinates of the tangent points are obtained as follows: (0, 600), ) It is obvious The coordinates should be Penetrate the end point Coordinates: Find the line Upper unit vector beg Coordinates: Solving Obviously By repeating the above steps, the coordinates of each peripheral hole on the arch contour line in the positive X-axis direction can be obtained; It should be noted that the penetration length of the last peripheral hole should be adjusted, such as by reducing the charge amount, to ensure that it does not penetrate too deeply into the surrounding rock at the sidewall. The coordinates of the peripheral holes of the arch outline in the negative X-axis direction can be obtained by symmetry. The method for determining the position of each peripheral hole on the outline of the inverted arch is the same as above, and will not be elaborated further here; It should also be noted that, for actual engineering applications, errors caused by the construction environment, equipment, and the skill level of personnel may result in a certain error between the actual peripheral holes and the calculated peripheral holes. However, during construction, care should be taken to ensure that the error is not too large, and it should generally be less than 5cm to meet the control standards for maximum over-excavation and average linear over-excavation. Find the slope: For example (99.310,591.724) Differentiating the functional expression for the arch contour line, we can obtain... Transform into an angle: Convert the slope to an angle using the formula. It can be concluded that (because The result is in radians, so it must be converted to angles. Substituting -0.1678 into the formula, we can obtain the angle that the energy-concentrating device 3 should be rotated to when it is installed, which is -9.53°. This angle should be the angle between the line connecting the top corners of the two energy-concentrating grooves 32 when the energy-concentrating device 3 is placed horizontally and the line connecting the top corners of the two energy-concentrating grooves 32 after rotation. S4. Based on the data determined in step S3, perform wire-connected blasting; S5. Inspect and evaluate the blasting effect; The blasting effect is evaluated based on the quantitative indicators of half-hole ratio, maximum over-excavation and average linear over-excavation specified in the prescribed face profile. If there are results that do not meet the standards, the data involved in steps S2-S4 should be adjusted for the next blasting. Half-porosity: The ratio of the total length of the visible semi-circular hole marks remaining after blasting to the total designed length of the surrounding holes within the same circulation section. The half-hole ratio after blasting should not be less than 85%; Maximum over-excavation value: In this embodiment, the maximum over-excavation value is located at the intersection of the penetration points of the two peripheral holes. For example Average linear over-excavation: .

Claims

1. A method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines, wherein the cross-section contour lines include the excavation cross-section contour line (1) and the inner contour line of the lining inside (2), characterized in that, Includes the following steps: S1. Construct a piecewise function expression based on the inner contour line of the lining (2); S2. Determine the set hole depth of a single hole on the outline of the excavation section (1), and the blasting penetration length of the penetration crack (4) under the set charge amount. S3. Based on the data determined in steps S1 and S2, calculate the number of peripheral holes to be opened on the excavation section outline (1) and the angle at which the energy-concentrating device (3) of each peripheral hole should be deflected. S4. Based on the data determined in step S3, perform wire-connected blasting; S5. Inspect and evaluate the blasting effect.

2. The method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines according to claim 1, characterized in that, Step S1 is as follows: S1.1 Determine the relative position; S1.1.1 Divide the inner contour line (2) of the lining into multiple segments of the first contour line, which in turn contain multiple segments of the first arc contour line. The excavation section outline (1) includes multiple segments of second arc outlines concentric with the first arc outline; S1.1.

2. Taking the center O of one segment of the second arc contour line that needs to be calculated as the reference point, the centers O of multiple segments of the second arc contour line are... n Represented using coordinates; S1.2, Determine the origin of the coordinate system; Establish a Cartesian coordinate system XOY, and represent the coordinates of the centers of the multiple second arc contour lines on the XOY plane; S1.3 represents the cross-sectional outline; The multiple segments of the second arc contour are represented in the form of functions; S1.4 Determine the range and domain; Based on the construction drawings of the cross-sectional contour lines, calculate and determine the range and domain of the functions corresponding to multiple segments of the second arc contour lines.

3. The method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines according to claim 2, characterized in that, In step S1.2, the inner contour line (2) of the lining is an axisymmetric figure, and the origin of the plane rectangular coordinate system XOY is located on the axis of symmetry.

4. The method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines according to claim 3, characterized in that, In step S1.2, the second arc-shaped contour line includes the arch contour line and the inverted arch contour line, and the origin of the plane rectangular coordinate system XOY is the center O1 of the arch contour line.

5. The method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines according to claim 1, characterized in that, In step S2, the blasting penetration length is determined based on hydrological and geological survey data before construction, as well as blasting scheme design procedures, and through engineering experience summaries, numerical simulations, and similar simulation experiments.

6. The method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines according to claim 5, characterized in that, In step S2, typically: For Class I and II surrounding rock, the penetration length is 30-90 cm when the charge is 300-400 g / m. For Class III and IV surrounding rock, the penetration length is 20-70 cm when the charge is 200-300 g / m. For Class V and VI surrounding rock, the penetration length is 10-30cm when the charge is 100-200g / m.

7. The method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines according to claim 1, characterized in that, In step S3: The number of peripheral holes and the deflection angle of the energy-concentrating device (3) are calculated based on the over-excavation limit of the face profile, the length of the penetration crack (4), and the cross-sectional profile.

8. The method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines according to claim 7, characterized in that, In step S3, the specific steps for determining the number of peripheral holes are as follows: AS3.1 Determine the maximum over-excavation value and the average linear over-excavation value according to the over-excavation limit regulations; AS3.

2. Based on existing research data and engineering experience, and in combination with different lithology and charge parameters, determine the length of the penetration fracture (4); AS3.

3. Based on the data obtained in steps AS3.1 and AS3.2, calculate the number and location of the surrounding holes and convert them into points on the excavation section outline (1) in the coordinate system.

9. The method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines according to claim 7, characterized in that, In step S3, the specific steps for determining the deflection angle of the energy focusing device (3) are as follows: BS3.1 Treat the blast hole as a point on the excavation section outline (1) and calculate the tangent slope at that point; BS3.2 converts the slope into an angle to achieve precise positioning of the energy-concentrating cutting angle.

10. The method for precise positioning of shaped charge blasting angle based on tunnel cross-section contour lines according to claim 1, characterized in that, Step S5 is as follows: The blasting effect is evaluated based on the quantitative indicators of half-hole ratio, maximum over-excavation, and average linear over-excavation specified in the prescribed working face profile. If there are results that do not meet the standards, the data involved in steps S2-S4 should be adjusted for the next blasting.

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