Blasting generation protection method for slope leaning platform of rock mass slope

Abstract

The invention discloses a blasting generation protection method for a rock slope leaning platform, and relates to the technical field of open-cast mining slope protection, a production main blasting hole, a production auxiliary hole and a presplitting blasting hole are formed in a to-be-blasted slope, immersed tube grouting holes are formed in a to-be-reserved slope, and the immersed tube grouting holes are linearly distributed at intervals; main structure steel parts are placed in the immersed tube grouting holes, gaps between the main structure steel parts and the immersed tube grouting holes are filled with cement mortar, a slope protection wall close to the slope step is formed, and the stability of the slope to be reserved is enhanced; the pre-splitting blasting holes are linearly distributed at intervals, the pre-splitting blasting holes are firstly blasted to form a pre-splitting area, and a boundary is formed between the side slope to be reserved and the side slope to be blasted; the production main blasting holes and the production auxiliary holes continue blasting, so that the side slope to be blasted is broken; a main structure steel part and cement mortar are arranged in an immersed tube grouting hole for strengthening and fixing, so that the boundary of the slope to be reserved is kept stable, and the completeness of parameters of the broken rock mass slope is kept after blasting.

Description

Technical Field

[0001] The present invention relates to the technical field of open-pit mining slope protection, and particularly relates to a protection method for generating a bench by blasting on a rock slope Background Art

[0002] The safety problem of high and steep slopes in open-pit mines has become a key problem to be solved urgently in the mining field. Especially under the condition that the cleavage fissures of the slope rock mass are developed, the stability and safety of the slope face severe challenges.

[0003] The process of approaching the final slope or the existing slope in open-pit mining is called the bench approach process. Special attention needs to be paid to the stability of the slope during this process to ensure the safety and efficiency of mining.

[0004] Under the condition that the cleavage fissures of the slope rock mass are developed, firstly, the single-step slope is prone to wedge failure, and the broken rock mass has the risk of collapse at any time. The falling rocks on the high and steep slope are extremely likely to cause losses to the construction road, personnel, and equipment. Secondly, the wedge failure of the single-step slope will lead to an insufficient width of the safety bench or even bench connection, affecting the later production and increasing the cost investment in slope protection during production.

[0005] At present, the general protection measures adopt pre-splitting blasting or smooth blasting to form a pre-crack at the excavation boundary to control the contour shape after blasting and reduce the damage to the remaining rock mass. However, there is a problem of short self-stabilization exposure time for the fractured rock slope. This is because the time used for the technological processes of blasting, loading, transportation, and slope cleaning during the bench approach process in open-pit mines is relatively long. For the fractured rock slope, as the bench slope face is exposed to the air, losing the support of the outer rock mass, the inner fractured rock mass will quickly undergo wedge failure under loosening and unloading. Even if protection measures such as cable anchor lattice beams and shotcrete reinforcement are adopted after bench approach, the integrity of the slope parameters cannot be guaranteed.

[0006] In view of this, extending the self-stabilization exposure time of the fractured rock slope to provide time for implementing reinforcement measures after bench approach for important slopes, that is, solving the integrity problem of the fractured rock slope parameters to achieve the purpose of slope protection, is the technical problem to be solved currently. Summary of the Invention

[0007] The core of the present invention is to provide a protection method for generating a bench by blasting on a rock slope. A grouting hole with a sinking pipe is set on the slope to be retained, and the strength of the boundary is enhanced by main structural steel members and cement mortar. A pre-splitting blasting hole is used to pre-form a broken boundary to reduce the influence on the slope to be retained when blasting the slope to be blasted, and keep the integrity of the fractured rock slope parameters after blasting.

[0008] A protection method for generating a bench by blasting on a rock slope includes:

[0009] Production main blasting holes, production auxiliary holes and pre-splitting blasting holes are drilled on the slope to be blasted; the pre-splitting blasting holes are arranged at intervals in a line; blasting materials are placed among the production main blasting holes, the production auxiliary holes and the pre-splitting blasting holes;

[0010] Immersed tube grouting holes are drilled on the slope to be retained; the immersed tube grouting holes are arranged at intervals in a line, and there is a preset distance L between the connecting line of the immersed tube grouting holes and the connecting line of the pre-splitting blasting holes;

[0011] Main structural steel members are placed in the immersed tube grouting holes, and the gap between the main structural steel members and the immersed tube grouting holes is filled with cement mortar to form a protection wall for the stepped slope of the slope protection;

[0012] The pre-splitting blasting holes are blasted first to form a pre-splitting area; the production main blasting holes and the production auxiliary holes are blasted continuously to break the slope to be blasted.

[0013] Optionally, the depth of the immersed tube grouting holes exceeds the height of the slope to be retained by more than 0.5 m;

[0014] The length of the main structural steel members is equal to the depth of the immersed tube grouting holes.

[0015] Optionally, the immersed tube grouting holes are arranged vertically.

[0016] Optionally, the main structural steel members are steel pipes, and the diameter of the steel pipes is 2 / 3 of the diameter of the immersed tube grouting holes.

[0017] Optionally, the diameter of the immersed tube grouting holes is equal to the diameter of the pre-splitting blasting holes.

[0018] Optionally, the distance between the connecting line of the immersed tube grouting holes and the connecting line of the pre-splitting blasting holes is 0.5 - 1 m.

[0019] Optionally, the distances between adjacent immersed tube grouting holes are equal, and the distances between adjacent pre-splitting blasting holes are equal;

[0020] The distances between the immersed tube grouting holes are equal to the distances between the pre-splitting blasting holes; and the immersed tube grouting holes and the pre-splitting blasting holes are arranged staggeredly.

[0021] Optionally, the production main blasting holes, the production auxiliary holes and the pre-splitting blasting holes are arranged obliquely;

[0022] The production main blasting holes and the production auxiliary holes are parallel;

[0023] The angle between the pre-splitting blasting holes and the horizontal plane is less than the angle between the production main blasting holes and the horizontal plane.

[0024] Optionally, a three-dimensional imaging system is used to perform periodic monitoring on the slope to be blasted and the slope to be retained through an unmanned aerial vehicle lidar, and the positioning data of the immersed tube grouting holes is recorded.

[0025] Focus on inspecting the fractured rock mass area, and record the displacement changes of the slope to be blasted and the slope to be retained before and after blasting in real time, and take corresponding measures according to the amplitude of the displacement change.

[0026] The present invention provides a method for generating protection for a rock slope bench blasting. Production main blast holes, production auxiliary holes and pre-splitting blast holes are opened on the slope to be blasted, and explosives are placed in the production main blast holes, production auxiliary holes and pre-splitting blast holes; Immersed tube grouting holes are opened on the slope to be retained, and the immersed tube grouting holes are arranged in a linear interval distribution, and there is a preset distance L between the connection line of the immersed tube grouting holes and the connection line of the pre-splitting blast holes; Main structural steel members are placed in the immersed tube grouting holes, and cement mortar is filled in the gap between the main structural steel members and the immersed tube grouting holes to form a protection wall for the bench slope surface, strengthening the stability of the slope to be retained; The pre-splitting blast holes are arranged in a linear interval distribution, and the pre-splitting blast holes are first blasted to form a pre-splitting area, so that the slope to be retained and the slope to be blasted are separated; The production main blast holes and production auxiliary holes continue to be blasted to break the slope to be blasted; By strengthening and fixing the main structural steel members and cement mortar in the immersed tube grouting holes, the boundary of the slope to be retained is kept stable, and the integrity of the fractured rock slope parameters is maintained after blasting. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a top view of the hole layout for the method of generating protection for the rock slope bench blasting of the present invention;

[0029] Figure 2 It is a side view of the hole layout for the method of generating protection for the rock slope bench blasting of the present invention;

[0030] Figure 3 It is a schematic diagram of the inflow of cement mortar into the immersed tube grouting hole;

[0031] Figure 4 It is a schematic diagram of the force on the main structural steel member in the immersed tube grouting hole;

[0032] Figure 5 It is a schematic diagram of the scanning of the slope by an unmanned aerial vehicle;

[0033] Figure 6Schematic diagram for the UAV to record the hole positions of the grouting holes for the immersed tube.

[0034] As shown in the figure:

[0035] Slope to be blasted 10; Production main blast holes 110; Production auxiliary holes 120; Presplitting blast holes 130;

[0036] Slope to be retained 20; Grouting holes for the immersed tube 210; Main structural steel members 211. Specific implementation manner

[0037] In order to enable those skilled in the art to better understand the technical solution of the present invention, the following will combine the accompanying drawings and specific implementation manners to introduce and explain in detail the method for generating protection by blasting the bench of the rock slope of the present invention.

[0038] The slope is composed of fragmented rock mass, and its joints and fissures are relatively developed, which is prone to cause the phenomenon of single-step wedge body failure, and then cause the incomplete state of the slope. Therefore, corresponding protection measures are required. The method for generating protection by blasting the bench of the rock slope of the present invention is applied to the field of open-pit mining. It is necessary to blast the slope of the mine, and the stability of the slope should be maintained after blasting.

[0039] Combined with Figure 1 , Figure 2 As shown, taking the dotted line B as the boundary, it is divided into the slope to be blasted 10 and the slope to be retained 20. The slope to be blasted 10 is the part that needs to be removed after blasting, and the slope to be retained 20 is the part that needs to be retained after blasting. From documents such as engineering geological reports, geological exploration data, and historical blasting records, query detailed information about the geological structure, rock layer distribution, lithological characteristics, groundwater conditions, weathering degree, etc. of the slope engineering geological zoning. Analyze the geological conditions of the slope, especially pay attention to the factors affecting the blasting effect, such as soft interlayers, faults, and the development of joints and fissures. After determining the range of the rock mass broken area, evaluate its impact on the stability of the bench in the blasting area, and on-site confirm and find the rock mass broken area caused by the main blast hole blasting to determine the protection area of the bench.

[0040] The method for generating protection by blasting the bench of the rock slope of the present invention includes the following steps:

[0041] According to the analysis results of the geological conditions, design the hole layout plan for the presplitting holes. On the ground of the protection area, according to the hole layout plan, use marking tools (such as spray paint, etc.) to mark the hole positions of the presplitting blast holes 130. According to the hole positions and spacings of the presplitting blast holes 130, calculate the positions of the grouting holes 210 for the immersed tube.

[0042] Use measuring tools or calculation software to accurately determine the coordinates and positions of each immersed tube grouting hole 210. On the ground within the protection area, use a marking tool to mark the positions of the immersed tube grouting holes 210. Inspect the marked positions of the pre-splitting blasting holes 130 and the immersed tube grouting holes 210 to ensure they meet the design requirements. Based on the design drawings and on-site markings, confirm the exact positions of the immersed tube grouting holes 210. Use measuring tools (such as total stations, GPS, etc.) to recheck the drilling positions to ensure they are correct.

[0043] On the slope 10 to be blasted, production main blasting holes 110, production auxiliary holes 120, and pre-splitting blasting holes 130 are drilled; multiple production main blasting holes 110, multiple production auxiliary holes 120, and multiple pre-splitting blasting holes 130 are distributed at intervals on the slope 10 to be blasted; among them, the pre-splitting blasting holes 130 are arranged linearly at intervals, and the connecting line formed by the pre-splitting blasting holes 130 can be a straight line, or other irregular connecting lines such as curves or wavy lines.

[0044] The pre-splitting blasting holes 130 are arranged at the junction between the slope 10 to be blasted and the slope 20 to be retained, and the purpose of the pre-splitting blasting holes 130 is to form a boundary between the slope 10 to be blasted and the slope 20 to be retained.

[0045] Explosives are placed in the production main blasting holes 110, production auxiliary holes 120, and pre-splitting blasting holes 130, and the blasting energy of the explosives in the pre-splitting blasting holes 130 is less than that of the explosives in the production main blasting holes 110 and production auxiliary holes 120. The production main blasting holes 110 and production auxiliary holes 120 are mainly used to break the solid structure of the slope 10 to be blasted, while the pre-splitting blasting holes 130 are used to pre-form a boundary gap. The spacing between adjacent pre-splitting blasting holes 130 is less than the spacing between adjacent production main blasting holes 110 and less than the spacing between adjacent production auxiliary holes 120. There is a small spacing between each pre-splitting blasting hole 130 to ensure that a gap can be formed after the explosives in the pre-splitting blasting holes 130 explode.

[0046] Immersed tube grouting holes 210 are drilled on the slope 20 to be retained, and the immersed tube grouting holes 210 are arranged linearly at intervals. The connecting line formed by the immersed tube grouting holes 210 can be a straight line, or other irregular connecting lines such as curves or wavy lines.

[0047] Combined Figure 1 As shown, there is a preset spacing L between the connecting line of the immersed tube grouting holes 210 and the connecting line of the pre-splitting blasting holes 130. The connecting line formed by the immersed tube grouting holes 210 is generally parallel to the connecting line formed by the pre-splitting blasting holes 130, and the preset spacing L at different positions of the two connecting lines is generally equal. It should be noted that the preset spacing L is not limited to a fixed value, and different values can be taken at different positions.

[0048] Place the main structural steel member 211 in the immersed tube grouting hole 210, and the main structural steel member 211 plays a role in strengthening the support; the outer diameter of the main structural steel member 211 is smaller than the inner diameter of the immersed tube grouting hole 210, and cement mortar is filled in the gap between the main structural steel member 211 and the immersed tube grouting hole 210, and the cement mortar surrounds the outer periphery of the main structural steel member 211. Combined with Figure 3 As shown, the vertical section of the immersed tube grouting hole 210 is shown. The main structural steel member 211 is surrounded by cement mortar, and the cement mortar can be filled into the joint cracks of the formation. After the cement mortar solidifies, a protection wall of the bench slope is formed by the main structural steel member 211 and the cement mortar.

[0049] The present invention adopts the process of adding the immersed tube grouting hole 210 after the pre-splitting blasting hole 130 and applying the immersed tube grouting process. The upper half of the immersed tube grouting hole 210 can resist the acting force of the broken rock mass on the broken rock mass slope, and the lower half is arranged behind the blasting area to absorb the blasting vibration transmitted from the blasting area, reduce the damage of the blasting to the broken rock mass slope, generate an anti-sliding effect, and the poured cement mortar can improve the strength of the grouting pipe inside the steel pipe. The cement mortar poured outside the main structural steel member 211 and inside the drill hole can flow along the larger cracks in the rock mass, play a cementing role on the broken rock mass, and the mortar cementation forms a protection wall of the bench slope, extending the exposure time of the self-stability of the fractured rock mass slope, providing time for subsequent reinforcement measures after the important slope is supported against the slope to solve the integrity problem of the parameters of the fractured rock mass slope, and achieving the purpose of protecting the slope.

[0050] The cement mortar is poured into the gap between the main structural steel member 211 and the hole wall of the immersed tube grouting hole 210, which can effectively fill these gaps, form a more compact and integral structure, and have high compressive and flexural strengths. When the main structural steel member 211 is lowered into the pre-drilled immersed tube grouting hole 210, it can effectively resist the deformation caused by external loads, thereby providing stable structural support, improving the overall stability and bearing capacity of the broken rock mass, and playing an anti-sliding role. Combined with Figure 4 As shown, it represents the stress state of the main structural steel member 211. On the other hand, the cement mortar will fill the tiny pores and cracks in the fractured rock mass, reduce the pore space, make the fractured rock mass form a more compact and integral structure, and play a cementing role on the fractured rock mass. Thirdly, pouring the cement mortar can seal the seepage channels in the fractured rock mass, reduce the seepage effect of groundwater, and partially eliminate the potential safety hazards caused by the seepage of groundwater.

[0051] Therefore, placing the main structural steel member 211 in the immersed tube grouting hole 210 and pouring the cement mortar can form a protection wall along the bench slope. The protection wall can limit the development space of the wedge body, reduce the possibility of its destruction, reduce the wedge body destruction of a single bench, ensure the integrity of the supported platform, and ensure the stability of the overall slope.

[0052] After grouting the immersed tube grouting hole 210, it is necessary to cure the grout to ensure that it reaches sufficient strength. The curing time depends on the type and formula of the grout and usually ranges from several days to several weeks. After the curing is completed, the strength of the grout needs to be inspected. Methods such as core sampling, rebound hammer testing or ultrasonic testing can be used to evaluate the compressive strength and integrity of the grout. After the grout is cured to reach the required strength, the pre-splitting blasting construction of the side support is carried out.

[0053] During the blasting construction operation, the pre-splitting blasting holes 130 are blasted first to form a pre-splitting zone. At this time, the production main blasting holes 110 and the production auxiliary holes 120 have not been blasted yet. After the pre-splitting blasting holes 130 are blasted, a section of crack is formed, and this crack serves as the boundary between the slope to be blasted 10 and the slope to be retained 20.

[0054] The production main blasting holes 110 and the production auxiliary holes 120 continue to be blasted after the pre-splitting blasting holes 130 are blasted. The production main blasting holes 110 and the production auxiliary holes 120 release greater energy after blasting, causing the slope to be blasted 10 to be broken. Since a section of crack is formed after the pre-splitting blasting holes 130 are blasted, a gap is formed between the slope to be blasted 10 and the slope to be retained 20, reducing the impact of the blasting power on the slope to be retained 20. In addition, the protection wall formed after the main structural steel members 211 and the cement mortar in the immersed tube grouting hole 210 are solidified can enhance the strength of the edge part of the slope to be retained 20, and can better resist the impact from the slope to be blasted 10, so as to keep the boundary of the slope to be retained stable and maintain the integrity of the fragmented rock slope parameters after blasting.

[0055] On the basis of the above scheme, the depth of the immersed tube grouting hole 210 exceeds the height of the slope to be retained 20 by more than 0.5 m; combined with Figure 2 As shown, the dotted line A represents the lowest point of the slope to be blasted 10, and the distance D represents the dimension by which the immersed tube grouting hole 210 extends below the slope to be retained 20, D≥0.5 m. The length of the main structural steel member 211 is equal to the depth of the immersed tube grouting hole 210. The depth of the immersed tube grouting hole 210 exceeds the height of the side support step by more than 0.5 m, and the bottom end of the main structural steel member 211 can extend deeper into the ground and form a more firm bond with the formation.

[0056] Combined with Figure 2 As shown, the immersed tube grouting hole 210 of the present invention is arranged vertically, perpendicular to the horizontal plane. The use of vertical holes is convenient for drilling. After the drilling is completed, it is necessary to accept the drilling and check whether the depth, diameter, inclination, etc. of the drilling meet the design requirements.

[0057] The main structural steel member 211 is a steel pipe with a diameter of 2 / 3 of the diameter of the immersed tube grouting hole 210, ensuring that the main structural steel member 211 has sufficient support strength. The hollow design of the steel pipe reduces material usage. Mortar with a strength not lower than M15 is injected into the gap between the steel pipe and the immersed tube grouting hole 210, and the grouting slurry is guaranteed to have a certain pressure to ensure that the inner and outer voids of the steel pipe are filled with the slurry.

[0058] The diameter of the immersed tube grouting hole 210 is equal to the diameter of the pre-splitting blasting hole 130, and the same drilling equipment is used for the immersed tube grouting hole 210 and the pre-splitting blasting hole 130, which helps to simplify the construction process.

[0059] The distance between the connecting lines of the immersed tube grouting holes 210 and the connecting lines of the pre-splitting blasting holes 130 is 0.5 - 1 m, that is, the value range of the above-mentioned preset distance L is 0.5 - 1 m, including the two end values. If the distance is too large, it is difficult for the main structural steel member 211 and the mortar in the immersed tube grouting hole 210 to strengthen the slope in the area of the cracks formed after the blasting of the pre-splitting blasting hole 130; if the distance is too small, the blasting of the pre-splitting blasting hole 130 will impact the main structural steel member 211 and the mortar in the immersed tube grouting hole 210, weakening the strengthening effect.

[0060] On the basis of any of the above technical solutions and their combinations, the distances between adjacent immersed tube grouting holes 210 are equal, and the distances between adjacent pre-splitting blasting holes 130 are equal; combined Figure 1 As shown, where G1 represents the distance between adjacent immersed tube grouting holes 210, and G2 represents the distance between adjacent pre-splitting blasting holes 130. The immersed tube grouting holes 210 are arranged and distributed at equal intervals, and the pre-splitting blasting holes 130 are arranged and distributed at equal intervals.

[0061] The distance between the immersed tube grouting holes 210 is equal to the distance between the pre-splitting blasting holes 130, that is, G1 = G2; and the immersed tube grouting holes 210 and the pre-splitting blasting holes 130 are arranged staggeredly. Figure 1 In the shown situation, the immersed tube grouting holes 210 are distributed along the X-axis connection line, and the pre-splitting blasting holes 130 are distributed along the X-axis connection line. In the Y-axis direction among them, the immersed tube grouting holes 210 and the pre-splitting blasting holes 130 are not on the same straight line. The immersed tube grouting holes 210 are located on the perpendicular bisectors of two adjacent pre-splitting blasting holes 130, and the pre-splitting blasting holes 130 are located on the perpendicular bisectors of two adjacent immersed tube grouting holes 210. By arranging the immersed tube grouting holes 210 and the pre-splitting blasting holes 130 staggeredly, the impact of the blasting of the pre-splitting blasting holes 130 on the immersed tube grouting holes 210 is reduced.

[0062] Combined Figure 2 As shown, the production main blasting holes 110, the production auxiliary holes 120, and the pre-splitting blasting holes 130 are inclined, and the production main blasting holes 110 are arranged parallel to each other, the production auxiliary holes 120 are arranged parallel to each other, and the pre-splitting blasting holes 130 are arranged parallel to each other.

[0063] The production main blasting holes 110 and the production auxiliary holes 120 are arranged in parallel. The angle between the pre-splitting blasting holes 130 and the horizontal plane is smaller than the angle between the production main blasting holes 110 and the horizontal plane. Figure 2 The angle between the production main blasting holes 110 and the horizontal plane is α, and the angle between the pre-splitting blasting holes 130 and the horizontal plane is β, where α > β.

[0064] Combined Figure 5 、 Figure 6 As shown, through the drone lidar scanning three-dimensional imaging system, the slope 10 to be blasted and the slope 20 to be retained are monitored periodically, and the positioning data of the grouting holes 210 in the immersed tube are recorded; the fractured rock mass area is inspected key points, and the displacement changes of the slope 10 to be blasted and the slope 20 to be retained before and after blasting are recorded in real time, and corresponding measures are taken according to the displacement change amplitude. If the change in this area is obvious and exceeds the preset range, corresponding measures should be taken in time.

[0065] The present invention is a method for generating protection for the bench platform of a rock slope by blasting. After the pre-splitting blasting holes 130, grouting holes 210 in the immersed tube are added and the immersed tube grouting process is adopted, so that the anti-sliding of the steel pipe and the cementation of the mortar act together to form a protection wall for the bench slope surface, extend the exposure time of the self-stability of the fractured rock slope, provide support for ensuring the integrity of the slope parameters, and reduce the slope support and maintenance costs.

[0066] The present invention can effectively extend the exposure time of the self-stability of the fractured rock slope, provide time for implementing reinforcement measures after the important slope is benched, solve the problem of the integrity of the fractured rock slope parameters, achieve the purpose of protecting the slope, and improve the safety and stability of the slope.

[0067] The technical implementation of the present invention is simple. By adding grouting holes 210 in the immersed tube after the pre-splitting holes and adopting the immersed tube grouting process, the anti-sliding of the steel pipe and the cementation of the mortar act together to form a protection wall for the bench slope surface, extend the exposure time of the self-stability of the fractured rock slope, provide support for ensuring the integrity of the slope parameters, the operation implementation is simple, the work efficiency is high, it can effectively reduce the slope support and maintenance costs, and it can be widely used for reference in similar open-pit mines and is worthy of wide promotion.

[0068] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A protection method for generating a bench platform by blasting on a rock slope, characterized in that, Including: Production main blasting holes (110), production auxiliary holes (120) and pre-splitting blasting holes (130) are formed on the slope to be blasted (10); the pre-splitting blasting holes (130) are arranged linearly and spaced apart; blasting materials are placed in the production main blasting holes (110), the production auxiliary holes (120) and the pre-splitting blasting holes (130); Immersed tube grouting holes (210) are formed on the slope to be retained (20); the immersed tube grouting holes (210) are arranged linearly and spaced apart, and there is a preset spacing L between the connecting line of the immersed tube grouting holes (210) and the connecting line of the pre-splitting blasting holes (130); Main structural steel members (211) are placed in the immersed tube grouting holes (210), and the gap between the main structural steel members (211) and the immersed tube grouting holes (210) is filled with cement mortar to form a protection wall for the stepped slope of the rib; The pre-splitting blasting holes (130) are first blasted to form a pre-splitting zone; the production main blasting holes (110) and the production auxiliary holes (120) are continuously blasted to break the slope to be blasted (10).

2. The protection method for generating a bench by blasting on a rock slope according to claim 1, characterized in that The depth of the immersed tube grouting holes (210) exceeds the height of the slope to be retained (20) by more than 0.5 m; The length of the main structural steel members (211) is equal to the depth of the immersed tube grouting holes (210).

3. The method for generating protection by blasting on the bench of a rock slope according to claim 2, characterized in that, The immersed tube grouting holes (210) are arranged vertically.

4. The protection method for generating a bench by blasting on a rock slope according to claim 1, characterized in that, The main structural steel members (211) are steel pipes, and the diameter of the steel pipes is 2 / 3 of the diameter of the immersed tube grouting holes (210).

5. The method for generating protection by blasting on the bench of a rock slope according to claim 1, characterized in that, The diameter of the immersed tube grouting holes (210) is equal to the diameter of the pre-splitting blasting holes (130).

6. The protection method for generating a bench by blasting on a rock slope according to claim 1, characterized in that, The spacing between the connecting lines of the immersed tube grouting holes (210) and the connecting lines of the pre-splitting blasting holes (130) is 0.5 - 1 m.

7. The method for generating protection by blasting the bench of a rock slope according to any one of claims 1 to 6, characterized in that The spacing between adjacent two immersed tube grouting holes (210) is equal, and the spacing between adjacent two pre-splitting blasting holes (130) is equal; The spacing between the immersed tube grouting holes (210) is equal to the spacing between the pre-splitting blasting holes (130); and the immersed tube grouting holes (210) and the pre-splitting blasting holes (130) are arranged staggeredly.

8. The method for generating protection by blasting on the bench of a rock slope according to claim 7, characterized in that, The production main blasting holes (110), the production auxiliary holes (120) and the pre-splitting blasting holes (130) are arranged obliquely; The production main blasting holes (110) and the production auxiliary holes (120) are parallel; The angle between the pre-splitting blasting holes (130) and the horizontal plane is less than the angle between the production main blasting holes (110) and the horizontal plane.

9. The method for generating protection by blasting of the bench for slope approaching in rock mass slopes according to claim 7, characterized in that, Through the drone lidar scanning three-dimensional imaging system, the slope to be blasted (10) and the slope to be retained (20) are periodically monitored, and the positioning data of the immersed tube grouting holes (210) are recorded; The broken rock mass area is inspected key points, and the displacement changes of the slope to be blasted (10) and the slope to be retained (20) before and after blasting are recorded in real time, and corresponding measures are taken according to the displacement change amplitude.

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