A spaced charging device for smooth blasting in tunnel excavation and a smooth blasting method

Abstract

The present invention discloses an interval charging device and a smooth blasting method for smooth blasting in tunnel excavation. The base rod of the interval charging device is a cylindrical tube and is provided with a connecting sleeve and a handle at the front and rear ends. The telescopic rod is telescopically sleeved in the connecting sleeve. A movable sleeve is slidably sleeved on the outer wall of the base rod near the connecting sleeve and a spring is provided inside. One end of the spring is connected to the movable sleeve and the other end is in contact with the handle. The switch is provided on the side wall of the handle and can limit the movement of the movable sleeve. The movable sleeve is circumferentially hinged with multiple support rods. The outer wall of the connecting sleeve or the base rod near the connecting sleeve is circumferentially hinged with multiple interval ribs, and the support rods are hinged to the corresponding interval ribs. The smooth blasting method includes the steps of measuring and arranging holes, drilling and charging, and blasting. The present invention can achieve precise positioning of the interval charging, which not only improves the smooth blasting effect, but also enhances the safety of the operation. It has the characteristics of simple structure, fast charging, accurate and reliable positioning, and reusability.

Description

Technical Field

[0001] The present invention belongs to the technical field of blasting engineering, and in particular relates to an interval charging device and a smooth blasting method for smooth blasting in tunnel excavation, which have the advantages of simple structure, rapid charging, accurate and reliable positioning, and reusability. Background Art

[0002] The mining industry plays a vital role in national economic development. Tunnel excavation is a prerequisite for ventilation, transportation, and mining operations. The quality of tunnel excavation directly impacts the smooth progress and speed of subsequent work. Tunnel excavation in underground mining projects is primarily of medium to small cross-section, with horizontal tunnel excavation accounting for approximately 25% of the total tunnel construction workload and 35-50% of the total construction period. Currently, two main methods are used for tunnel excavation: drilling and blasting and machine excavation. Drilling and blasting remains the predominant method for horizontal tunnel excavation due to its ability to adjust blasting design based on excavation dimensions and geological conditions, its adaptability to geological and topographical conditions, its flexibility, and its low excavation costs.

[0003] To ensure a smooth, even cross-section of the tunnel after blasting, smooth blasting or pre-splitting blasting is often used in the drill-and-blast method. Pre-splitting and smooth blasting, however, require controlled explosive dosage to protect the rock mass and prevent excessive damage to the rock face. This can be achieved with specialized low-strength explosives or uncoupled charge structures. However, due to changes in industrial explosives production technology, low-strength explosives are gradually being phased out of the market, and uncoupled charge structures are now generally preferred. While smooth blasting technology has been widely used in tunnel excavation in mining operations, the traditional method involves on-site preparation of smooth blasting charges. This is not only time-consuming and impacts construction schedules, but also subject to the constraints of individual worker quality, resulting in arbitrary positioning of uncoupled charges, severely impacting blasting quality and frequently causing over- and under-excavation. This not only impacts mining costs but can also lead to more serious blasting hazards such as roof falls. Although accurate smooth blasting parameters and reasonable blasting construction techniques can control the over-excavation and under-excavation of the tunnel to an acceptable level, and the tunnel profile formed by blasting is flat and smooth, while also causing little disturbance to the surrounding rock of the tunnel, during the uncoupled interval charging process of the smooth blasting peripheral holes, due to the deep blastholes, it is difficult for construction personnel to accurately space the explosives in the holes according to the blasting design. Moreover, relying on charging experience for air spacing often results in large errors and affects the blasting effect. To this end, the prior art often uses wooden poles, bamboo strips, or even slit tubes to tie the explosives outside the holes to improve the positioning accuracy of the interval charge inside the holes. However, the process of tying the explosives outside the holes is not only cumbersome and reduces construction efficiency, but also the difficulty of ensuring the stability and spacing of the explosives binding using wooden poles, bamboo strips, etc., and the relatively soft tools such as bamboo strips are difficult to reliably guide to the preset blasthole positions, making the uncoupled charging unreliable and the blasting effect difficult to guarantee. In addition, the disposable binding workpieces also increase the blasting cost. Summary of the Invention

[0004] In view of the shortcomings of the existing technology in which the uncoupled charging structure has a complicated charging process, low in-hole positioning accuracy, and non-reusable auxiliary tools, which lead to increased blasting costs, a spaced charging device for smooth surface blasting in tunnel excavation is provided, which has a simple structure, fast charging, accurate and reliable positioning, and is reusable. A smooth surface blasting method for tunnel excavation is also provided.

[0005] The interval charging device for smooth blasting in tunnel excavation of the present invention is realized as follows: it includes a telescopic rod, a connecting sleeve, a base rod, and a handle, the base rod is a cylindrical tube, the connecting sleeve and the handle are fixedly arranged at the front and rear ends of the base rod respectively, one end of the telescopic rod is telescopically sleeved in the connecting sleeve, a movable sleeve is slidably sleeved on the outer wall of the base rod close to the connecting sleeve, a spring is slidably arranged in the base rod, one end of the spring is connected to the movable sleeve and the other end abuts the end face of the handle, a switch is provided on the side wall of the handle, the switch can be opened and closed to limit the movement of the movable sleeve, the movable sleeve is hinged to multiple support rods along the circumferential direction, and multiple interval ribs corresponding to the support rods are hinged circumferentially on the outer wall of the connecting sleeve or the base rod close to the connecting sleeve, and the support rods are hinged to the interval ribs at corresponding positions.

[0006] The smooth blasting method for tunnel excavation of the present invention is implemented as follows: it includes the steps of measuring and arranging holes, drilling and charging, and blasting. The specific steps are as follows:

[0007] A. Measurement and hole layout: Measure and analyze the area in the tunnel to be blasted, and then design the blasthole and charge parameters based on the analysis;

[0008] B. Drilling and charging: Use a drilling rig to drill holes in the area to be blasted and inspect them. After passing the inspection, charge the slot holes and auxiliary holes first. Use the interval charging device used for smooth blasting in tunnel excavation to charge the peripheral holes of the tunnel section. Strictly follow the designed interval charging method and charging amount.

[0009] C. Blasting: After the charging is completed, the blast hole is filled. After the blast hole is filled and inspected and qualified, blasting is carried out.

[0010] Beneficial effects of the present invention:

[0011] 1. The present invention provides a telescopic rod at the front end of the base rod, and the length of the telescopic rod can be adjusted to adapt to the charging interval within a large range of variation; and a slidable movable sleeve is provided on the base rod. Through the combined action of the spring in the base rod and the switch on the bottom handle, the movable sleeve can be controlled to slide to push the peripheral support rods to open the spaced ribs to form a positioning surface for the spaced charges, so that the interval distance of the explosive bags in the peripheral holes of the smooth blasting in the tunnel excavation meets the design requirements, and the precise positioning of the spaced charges is achieved to improve the effect of the smooth blasting, and effectively avoid the over-excavation and under-excavation of the tunnel.

[0012] 2. The present invention simply adjusts the length of the telescopic rod in advance according to the blasting design. After insertion into the blasthole, a switch is operated to expand the spacer ribs to form a positioning surface for the spaced charge. The charge can then be placed and compacted as designed. The sliding sleeve is then operated to retract the spacer ribs backward and remove them from the blasthole. This process is repeated to complete the charge process. Therefore, the entire charge process eliminates the need for pre-measurement outside the hole, strapping, and other steps, significantly improving charge efficiency and reducing labor intensity. This also enhances the safety of blasting and subsequent operations. Furthermore, because the spaced charge device is reusable, it reduces construction costs compared to auxiliary tools such as wooden poles, bamboo strips, and even slit tubes.

[0013] 3. In the present invention, the charge bag with spaced charges in the blasthole can form an arc-shaped energy-gathering concave surface on the side of the charge bag due to the withdrawal of the spaced charge device. After the charge is detonated, an energy-gathering effect can be formed, and the explosive energy is more concentrated in the direction of the rock contour surface, which has a cutting effect on the rock mass, thereby effectively reducing the damage to the retained rock mass and facilitating the formation of a regular contour surface.

[0014] In summary, the present invention has the characteristics of simple structure, high construction efficiency, low labor intensity, and low construction cost and safety risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the natural state structure of the spacer charging device of the present invention;

[0016] Figure 2 for Figure 1 Schematic diagram of the structure of the interval positioning state in the blast hole;

[0017] Figure 3 for Figure 1 Schematic diagram of the structure in the extraction state in the blast hole;

[0018] Figure 4 for Figure 1 A partial enlarged view;

[0019] Figure 5 for Figure 2 A magnified image looking up;

[0020] In the figure: 1-telescopic rod, 101-bottom rod, 102-sliding rod, 2-connecting sleeve, 3-base rod, 301-sliding groove, 4-handle, 401-hook II, 5-movable sleeve, 501-slider, 502-movable plate, 6-spring, 7-switch, 8-support rod, 9-spacer rib, 10-control line I, 11-lever, 111-hook I, 12-connecting ring, 13-reset spring, 14-control line II, 15-ring. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, but the present invention is not limited in any way. Any changes or improvements made based on the teachings of the present invention fall within the scope of protection of the present invention.

[0022] like Figures 1 to 5 The cam 3 is a cylindrical tube, and the connecting sleeve 2 and the handle 4 are fixedly arranged at the front and rear ends of the base rod 3 respectively. One end of the telescopic rod 1 is telescopically sleeved in the connecting sleeve 2, and a movable sleeve 5 is slidably sleeved on the outer wall of the base rod 3 near the connecting sleeve 2. A spring 6 is slidably arranged in the base rod 3, and one end of the spring 6 is connected to the movable sleeve 5 and the other end abuts against the end face of the handle 4. A switch 7 is provided on the side wall of the handle 4, and the switch 7 can be opened and closed to limit the movement of the movable sleeve 5. The movable sleeve 5 is hinged to a plurality of support rods 8 along the circumferential direction, and a plurality of spaced ribs 9 corresponding to the support rods 8 are hinged circumferentially on the outer wall of the connecting sleeve 2 or the base rod 3 near the connecting sleeve 2, and the support rods 8 are hinged to the spaced ribs 9 at corresponding positions.

[0023] The telescopic rod 1 includes a bottom rod 101 and a sliding rod 102. The bottom end of the bottom rod 101 is detachably fixedly connected to the connecting sleeve 2. The sliding rod 102 is a first-level or second-level telescopic sliding rod and its bottom side can be slidably and telescopically nested in the side of the bottom rod 101 away from the connecting sleeve 2.

[0024] The outer circumferential surface of the slide rod 102 is provided with scale lines along the axis.

[0025] The base rod 3 is provided with an axially extending sliding groove 301 on the outer wall near the connecting sleeve 2, and a slider 501 is fixedly provided on the inner side of the movable sleeve 5, which slides with the sliding groove 301. The slider 501 extends into the base rod 3 and is also fixedly connected to a movable plate 502. One end of the spring 6 abuts against the movable plate 502 and the other end abuts against the end surface of the handle 4. The movable plate 502 is also fixedly connected to a control line Ⅰ10, one end of the control line Ⅰ10 is connected to the switch 7. The switch 7 releases the control line Ⅰ10 to move the movable sleeve 5 toward the side of the telescopic rod 1 to open each spaced umbrella rib 9 and make it perpendicular to the axis of the base rod 3.

[0026] like Figure 4 As shown, a lever 11 is horizontally hinged in the handle 4, the middle part of the lever 11 is hinged to the handle 4 and a hook Ⅰ111 is provided at one end, and the other end is hinged to the switch 7, the end of the control line Ⅰ10 away from the movable plate 502 is fixedly connected to a connecting ring 12, the connecting ring 12 is sleeved on the hook Ⅰ111, and the switch 7 is vertically slidably set on the side wall of the handle 4.

[0027] The lever 11 is provided with a return spring 13 from the middle hinge to the switch 7 side, and the two ends of the return spring 13 are respectively in contact with the handle 4 at the middle hinge and the end surface of the switch 7.

[0028] like Figure 5 As shown, the movable plate 502 is also connected to a control line II14, which passes through the spring 6 front and back and extends out of the bottom end of the handle 4. A ring 15 is fixedly connected to the control line II14. A C-shaped or V-shaped hook II401 is fixedly provided horizontally at the bottom end of the handle 4. The ring 15 is sleeved on the hook II401. When the hook II401 is released, the movable sleeve 5 continues to move toward the side of the telescopic rod 1 to open each spaced rib 9 to an axis parallel to the base rod 3.

[0029] The support rods 8 and the spacer ribs 9 are evenly distributed on the entire circumferential surface or evenly distributed within a 180° range of the circumferential surface.

[0030] The outer surface of the handle 4 and / or the switch 7 is wrapped with a rubber layer, the connecting sleeve 2, the movable sleeve 5, the connecting ring 12 and / or the sleeve 15 are made of hard plastic material, and the control line I10 and / or the control line II14 are steel wire ropes.

[0031] like Figures 1 to 5 As shown, the smooth blasting method for tunnel excavation of the present invention is characterized by comprising the steps of measuring and arranging holes, drilling and charging, and blasting. The specific steps are as follows:

[0032] A. Measurement and hole layout: Measure and analyze the area in the tunnel to be blasted, and then design the blasthole and charge parameters based on the analysis;

[0033] B. Drilling and charging: Use a drilling rig to drill holes in the area to be blasted and inspect them. After passing the inspection, charge the slot holes and auxiliary holes first. Then use the interval charging device used for smooth blasting in tunnel excavation to charge the peripheral holes of the tunnel section. Strictly follow the designed interval charging method and charging amount.

[0034] C. Blasting: After the charging is completed, the blast hole is filled. After the blast hole is filled and inspected and qualified, blasting is carried out.

[0035] In the step B, the length of the telescopic rod 1 is first adjusted according to the actual blasthole depth and the spacing distance, and then the aforementioned interval charging device for smooth blasting in tunnel excavation is placed into the blasthole, so that the top of the telescopic rod 1 contacts the bottom of the blasthole, ensuring that the actual charging depth is consistent with the design, and then the explosive rolls at the bottom of the blasthole are filled according to the design; after completing the filling of the explosive rolls at the bottom of the blasthole, the switch 7 on the control handle 4 releases the restriction on the movable sleeve 5, and the spring 6 in the compressed state pushes the movable sleeve 5 to slide toward one end of the connecting sleeve 2 under the action of the rebound force. During the sliding process of the movable sleeve 5, the support rods 8 push the interval ribs 9 to gradually unfold and be perpendicular to the axis of the base rod 3, thereby preventing the subsequently loaded explosive rolls from moving toward the bottom of the hole; the remaining explosive rolls are loaded into the hole to the position of the interval ribs 9 to make them reach the designed position.

[0036] In the step B, when the charge roll is loaded into the hole to the position of the spacer rib 9, the explosive bag and the detonator are inserted as needed according to the design. After compaction, the control line II14 on the control handle 4 is unhooked to release the restriction on the movable sleeve 5. The movable sleeve 5 continues to slide toward one end of the connecting sleeve 2 under the action of the rebound force of the spring 6 in the compressed state. The support rods 8 on it push the spacer ribs 9 to gradually retract toward the connecting sleeve 2. After waiting for a period of time, the handle 4 can be pulled outward to extract the entire charging device from the blast hole; then the control line II14 is pulled to make the ring 15 on it hang on the hook II401, and then the control line I10 is pulled to make the connecting ring 12 on it hang on the hook I111, completing the reset of the spacer ribs 9 pushed by the support rods 8; if the blast hole needs to continue to charge the charge at intervals, the above process can be repeated to complete it.

[0037] The blasthole filling material in step C is made of taphole mud, wherein the density of taphole mud is about 1.8g / cm 3 , Poisson's ratio is 0.2, apparent porosity is about 32%, shear strength at high temperature of 1450℃ is about 3.2~4.5MPa, and the filling length of the taphole mud is 40~60cm.

[0038] Example 1

[0039] like Figures 1 to 5As shown, at an underground copper mine in inland southwest China, tunnel excavation is primarily carried out by the mine itself and two outsourced construction companies, based on actual production conditions. During blasting operations, the area to be blasted was a 4×3.6m three-center arch. A Boomer-281 tunneling drilling rig was used for drilling, with a total of 48 to 52 holes drilled. No. 1 rock emulsion explosives were used, and the primary blasting equipment consisted of 1 to 10 sections of half-second detonating cord detonators, 2 to 15 sections of 25ms equally spaced detonating cord detonators, and digital electronic detonators. The rock had a Proctor coefficient of f=8 to 12, and moderate fissure development. Smooth blasting was used for all tunnel excavation at this mine, but the actual blasting results were less than expected. During construction, the peripheral holes were charged continuously, while the top holes were charged randomly based on the construction workers' experience. This resulted in poor tunnel contour formation, uneven walls, and even over- and under-excavation exceeding 30 cm. Therefore, the tunnel excavation smooth blasting method of the present invention is used to continue excavation. The specific process is as follows:

[0040] S100: Measure and analyze the area in the tunnel to be blasted, and then design the blasthole and charging parameters based on the analysis.

[0041] S200: In the area to be blasted, a drilling rig with a drilling efficiency of 5 to 9 m / d is used to drill the arranged blastholes to form blastholes with a diameter of 58 mm. After the drilling of all blastholes is completed, they are inspected to see if there are any blockages or perforations. After the inspection is qualified, the slot holes and auxiliary holes are first charged, and then the interval charging device for smooth blasting in tunnel excavation of the present invention is used to charge the peripheral holes of the tunnel section:

[0042] After the gun is in the working state, the gun barrel 1 is put into the working state, and the gun barrel 2 is put into the working state, and the gun barrel 3 is put into the working state, the gun barrel 3 is put into the working state, and ...

[0043] After the powder roll is loaded into the hole to the position of the spacer ribs 9, the explosive bag and detonator are inserted as needed according to the design. After compaction, the control line II14 on the control handle 4 is unhooked to release the restriction on the movable sleeve 5. The movable sleeve 5 continues to slide toward one end of the connecting sleeve 2 under the action of the rebound force of the spring 6 in the compressed state. The support rods 8 on it push the spacer ribs 9 to gradually retract toward the connecting sleeve 2. After waiting for a period of time, the handle 4 can be pulled outward to withdraw the entire charging device from the blast hole; then the control line II14 is pulled to make the ring 15 on it hang on the hook II401, and then the control line I10 is pulled to make the connecting ring 12 on it hang on the hook I111, completing the reset of the spacer ribs 9 pushed by the support rods 8; if the blast hole needs to continue to charge the powder at intervals, the above process can be repeated.

[0044] S300: After the charge is completed, the blasthole is filled and tamped, and blasting is carried out after the blasthole filling is completed and inspected to be qualified. Among them, due to the influence of economic cost and site conditions, the blasthole filling material is made of blasthole mud, and the density of the blasthole mud is about 1.8g / cm 3 , Poisson's ratio is 0.2, apparent porosity is about 32%, shear strength at high temperature of 1450℃ is about 3.2~4.5MPa, and the filling length of the taphole mud is 40~60cm.

[0045] Blasting effect: After the blasting is completed, the smooth surface blasting effect on site is analyzed and summarized. It is found that when the interval charging device is used for blasting, the smooth surface blasting effect is good, the overall wall of the formed tunnel is relatively flat, the semi-hole rate is as high as 73%, and the excavation footage is good, the blasthole utilization rate can reach 93.5%, and the blasting block size is uniform, basically no large blocks are produced, and there is no residual explosives or residual pipes. This shows that the tunnel excavation smooth surface blasting method of the present invention is applied well in the blasting operation of underground mines, and the interval charging device can accurately space the charging position according to the blasting design, thereby improving the blasting effect.

[0046] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A spaced charging device for smooth blasting in tunnel excavation, characterized in that: The invention comprises a telescopic rod (1), a connecting sleeve (2), a base rod (3), and a handle (4). The base rod (3) is a cylindrical tube. The connecting sleeve (2) and the handle (4) are fixedly arranged at the front end and the rear end of the base rod (3) respectively. One end of the telescopic rod (1) is telescopically sleeved in the connecting sleeve (2). A movable sleeve (5) is slidably sleeved on the outer wall of the base rod (3) near the connecting sleeve (2). A spring (6) is slidably arranged in the base rod (3). One end of the spring (6) is connected to the movable sleeve (5) and the other end abuts against the end surface of the handle (4). A switch (7) is arranged on the side wall of the handle (4). The switch (7) can be opened and closed to limit the movement of the movable sleeve (5). The movable sleeve (5) is hinged to multiple support rods (8) along the circumferential direction. Multiple support rods (8) are hinged to the outer wall of the connecting sleeve (2) or the base rod (3) near the connecting sleeve (2) along the circumferential direction. The spaced ribs (9) correspond to the support rod (8), and the support rod (8) is hinged to the spaced ribs (9) at the corresponding position; the outer wall of the base rod (3) near the connecting sleeve (2) is provided with a sliding groove (301) extending in the axial direction, and the inner side of the movable sleeve (5) is fixedly provided with a slider (501) that slides with the sliding groove (301), and the slider (501) extends into the base rod (3) and is also fixedly connected to a movable plate (502), one end of the spring (6) abuts against the movable plate (502) and the other end abuts against the end surface of the handle (4), and the movable plate (502) is also fixedly connected to the control line I (10), one end of the control line I (10) is connected to the switch (7), and the switch (7) releases the control line I (10) to move the movable sleeve (5) toward the side of the telescopic rod (1) to open each spaced rib (9) and perpendicular to the axis of the base rod (3); The movable plate (502) is also connected to a control line II (14), which passes through the spring (6) front and back and extends out of the bottom end of the handle (4). A collar (15) is fixedly connected to the control line II (14). A C-shaped or V-shaped hook II (401) is fixedly provided horizontally at the bottom end of the handle (4). The collar (15) is sleeved on the hook II (401). When the hook II (401) is released, the movable sleeve (5) continues to move toward the side of the telescopic rod (1) to open each spaced rib (9) to an axis parallel to the base rod (3).

2. The interval charging device for smooth blasting in tunnel excavation according to claim 1, characterized in that: The telescopic rod (1) comprises a bottom rod (101) and a sliding rod (102). The bottom end of the bottom rod (101) is detachably fixedly connected to the connecting sleeve (2). The sliding rod (102) is a first-level or second-level telescopic sliding rod, and the bottom side thereof is slidably and telescopically nested on a side of the bottom rod (101) away from the connecting sleeve (2).

3. The interval charging device for smooth blasting in tunnel excavation according to claim 1, characterized in that: A lever (11) is hinged horizontally in the handle (4), the middle portion of the lever (11) is hinged to the handle (4), one end of the lever (11) is provided with a hook I (111), and the other end is hinged to the switch (7), the end of the control line I (10) away from the movable plate (502) is fixedly connected to a connecting ring (12), the connecting ring (12) is sleeved on the hook I (111), and the switch (7) is vertically slidably provided on the side wall of the handle (4).

4. The interval charging device for smooth blasting in tunnel excavation according to claim 3, characterized in that: The lever (11) is provided with a return spring (13) from the middle hinge to the switch (7) side, and the two ends of the return spring (13) respectively abut against the handle (4) at the middle hinge and the end surface of the switch (7).

5. The interval charging device for smooth blasting in tunnel excavation according to claim 1, characterized in that: The support rods (8) and the spacer ribs (9) are evenly distributed circumferentially on the entire circumferential surface or evenly distributed circumferentially within a 180° range of the circumferential surface.

6. The interval charging device for smooth blasting in tunnel excavation according to claim 1, characterized in that: The outer surfaces of the handle (4) and the switch (7) are wrapped with a rubber layer, the connecting sleeve (2), the movable sleeve (5), the connecting ring (12) and the sleeve ring (15) are made of hard plastic material, and the control line I (10) and the control line II (14) are steel wire ropes.

7. A smooth blasting method for tunnel excavation, characterized in that: It includes the steps of measuring and arranging holes, drilling and charging, and blasting. The specific steps are as follows: A. Measurement and hole layout: Measure and analyze the area in the tunnel to be blasted, and then design the blasthole and charge parameters based on the analysis; B. Drilling and charging: Use a drilling rig to drill holes in the area to be blasted and inspect them. After passing the inspection, charge the slot holes and auxiliary holes first. Use the interval charging device for smooth blasting in tunnel excavation as described in any one of claims 1 to 6 to charge the peripheral holes of the tunnel section, and strictly follow the designed interval charging method and charging amount; C. Blasting: After the charging is completed, the blast hole is filled. After the blast hole is filled and inspected and qualified, blasting is carried out.

8. The smooth blasting method for tunnel excavation according to claim 7, characterized in that In the step B, the length of the telescopic rod (1) is first adjusted according to the actual blasthole depth and the spacing distance, and then the aforementioned interval charging device for smooth blasting of tunnel excavation is placed in the blasthole so that the top of the telescopic rod (1) contacts the bottom of the blasthole to ensure that the actual charging depth is consistent with the design, and then the explosive roll at the bottom of the blasthole is filled according to the design; after the filling of the explosive roll at the bottom of the blasthole is completed, the switch (7) on the control handle (4) releases the restriction on the movable sleeve (5), and the spring (6) in the compressed state pushes the movable sleeve (5) to slide toward one end of the connecting sleeve (2) under the action of the rebound force. During the sliding process of the movable sleeve (5), each interval rib (9) is pushed by each support rod (8) to gradually expand and be perpendicular to the axis of the base rod (3), thereby preventing the subsequent loaded explosive roll from moving toward the bottom of the hole; the remaining explosive rolls are loaded into the hole to the position of the interval rib (9) to reach the designed position.

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