Rock wall crane beam shaped charge blasting construction method

Abstract

This invention relates to the field of rock wall crane construction, specifically disclosing a method for shaped charge blasting of rock wall crane beams, comprising the following steps: Step S1, preparing for construction, surveying the integrity of the surrounding rock, and determining the locations of vertical and inclined blast holes; Step S2, drilling and cleaning towards the locations of the vertical and inclined blast holes; Step S3, pushing PVC shaped charge tubes into the vertical and inclined blast holes, with the opening facing the excavation contour surface, and sealing the vertical and inclined blast holes with stemming material. During the blasting of rock wall crane beams, distinguishing between vertical and inclined blast holes, and pushing PVC shaped charge tubes into the blast holes for blasting, the PVC shaped charge tubes can guide the detonation energy to be released along the excavation contour surface, reducing the error in the flatness of the rock platform, controlling the drilling accuracy, reducing subsequent repair work, and ensuring the blasting effect.

Description

Technical Field

[0001] This invention relates to the field of rock wall crane construction, specifically to a method for rock wall crane beam shaped charge blasting construction. Background Technology

[0002] The rock-wall crane beam is a key load-bearing structure of the underground powerhouse of a pumped-storage power station, and its excavation quality directly determines the accuracy of subsequent equipment installation and the safety of structural operation. Existing blasting construction methods for rock-wall crane beams suffer from the following core defects: 1. Unreasonable charge structure: The traditional method of "bamboo strips + small explosive cartridges with non-coupled intervals" results in discontinuous explosive distribution and uneven concentration of detonation energy, leading to poor flatness of the rock platform wall (height difference exceeding 15cm) and easy formation of deep detonation cracks in the borehole wall. 2. Poor parameter matching: The lack of a precise matching model for "hole spacing - linear charge density" and reliance on experience-based adjustments leads to unstable blasting results and over-excavation often exceeds the standard limit of 15cm. 3. Insufficient detonation accuracy: The use of ordinary detonators for detonation results in a large detonation time difference (≥5ms), which aggravates the damage to the surrounding rock due to the superposition of blasting vibrations and increases the risk of rockburst. Summary of the Invention

[0003] The purpose of this invention is to provide a method for constructing rock wall crane beams using focused blasting, in order to solve the technical problems existing in related technologies.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for constructing rock wall crane beams using focused blasting, comprising the following steps; Step S1: Prepare for construction by surveying the integrity of the surrounding rock and determining the locations of vertical and inclined blasting holes. Step S2: Drill and clean the holes at the locations of the vertical and inclined optical blasting holes; Step S3: Push the PVC cable tray energy-concentrating tube into the vertical and inclined blasting holes, with the opening of the tray facing the excavation outline, and use blasting mud to seal the vertical and inclined blasting holes.

[0005] As a further technical solution to the above scheme, in step S2, a drilling template is set up, and a guide tube is set on the drilling template for blast hole positioning. After drilling with a drilling machine, the hole is flushed with high-pressure air and clean water so that the rock powder residue is ≤5cm.

[0006] As a further technical solution to the above scheme, in step S3, the amount of explosive is weighed according to the difference between vertical optical detonation holes and inclined optical detonation holes, and the explosive is continuously and evenly coated to wrap the detonating cord and the inner wall of the PVC duct energy-conducting tube to form a gapless explosive layer.

[0007] As a further technical solution of the above scheme, in step S3, the gunning mud is a mixture of clay and sand.

[0008] Compared with the prior art, the present invention has the following advantages and beneficial effects: In this scheme, during the blasting construction of the crane beam on the rock face, vertical and inclined smooth blasting holes are distinguished. PVC cable groove energy-concentrating tubes are pushed into the smooth blasting holes for blasting. The PVC cable groove energy-concentrating tubes can guide the detonation energy to be released along the excavation contour surface, reduce the error of the rock platform flatness, control the drilling accuracy, reduce the amount of subsequent repair work, and ensure the blasting effect. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the construction environment for this project.

[0010] Figure 2 This is a schematic diagram of the drilling template.

[0011] Figure 3 This is a schematic diagram of the structure of a PVC cable tray energy-concentrating pipe.

[0012] The meanings of the labels in the diagram are as follows: Vertical light-burst hole-1; sloping light-burst hole-2; PVC cable trough energy-concentrating pipe-3; drilling template-4; guide tube-5. Detailed Implementation

[0013] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, so as to provide a better understanding of the concept of the present invention, the technical problem solved, the technical features constituting the technical solution, and the technical effects brought about.

[0014] like Figures 1-3 As shown, a method for constructing a rock wall crane beam using focused blasting includes the following steps; Step S1: Prepare for construction, survey the integrity of the surrounding rock, and determine the location of vertical blasting hole 1 and inclined blasting hole 2; Step S2: Drill and clean the holes toward the positions of the vertical light blasting hole 1 and the inclined light blasting hole 2; Step S3: Push the PVC cable tray energy-concentrating tube 3 into the vertical blasting hole 1 and the inclined blasting hole 2, with the opening of the tray facing the excavation outline, and use blasting mud to seal the vertical blasting hole 1 and the inclined blasting hole 2.

[0015] When using this device, geological surveys and preliminary parameter determination are first conducted to examine the integrity of the surrounding rock of the crane beam on the rock wall and determine the positions of the vertical blasting hole 1 and the inclined blasting hole 2. The depth of the vertical blasting hole 1 is 1.55 meters, and the depth of the inclined blasting hole 2 is 1.63 meters, with a uniform hole diameter of 42 mm and a hole spacing of 30 cm. PVC cable trays are used to fabricate shaped charge tubes to form PVC cable tray shaped charge tubes 3, with a wall thickness of 3-5 mm and a slot width of 25-30 mm. Ø32 mm rock emulsion explosive, detonating cord with a diameter ≥5 mm, high-precision digital electronic detonators (detonation time difference ≤1 ms), and a centralized controller are used. A YT-28 hand drill, a high-precision electronic scale (accuracy ±0.1 g), and an angle gauge (accuracy ±0.5°) are also provided. The prefabricated shaped charge tube is slowly pushed into the blasting hole, ensuring that the slot opening faces the excavation contour surface, and the alignment error between the two ends of the PVC cable tray shaped charge tube 3 and the blasting hole is ≤3 cm. When sealing, first set a rubber sealing plug at the end of the PVC cable trough energy-concentrating pipe 3 to fix the position, then fill it with self-made potting mud, the sealing length is ≥30cm and tamping it down.

[0016] Digital electronic detonators are connected to detonating cords, and a centralized controller is used to set the detonation sequence. The detonation time difference between adjacent blast holes (i.e., smooth blast holes) is ≤1ms to avoid vibration superposition. The blasting area is cleared, and detonation is carried out after confirming that no personnel remain. After blasting, the flatness of the rock platform (error ≤10cm), half-hole rate (≥90%), blast fracture depth (≤5m), and over-excavation (≤15cm) are checked. If the standards are not met, the linear charge density is adjusted and the test is repeated. By cleaning the smooth blast holes and blasting with PVC cable trays shaped charge tubes 3 installed, the PVC cable trays shaped charge tubes 3 guide the detonation energy to be released along the excavation contour surface. The flatness error of the rock platform is ≤10cm, and the drilling accuracy is controlled so that the actual over-excavation is ≤8cm, which is better than the standard limit of 15cm, reducing the amount of subsequent repair work and ensuring the blasting effect.

[0017] In a preferred embodiment, in step S2, a drilling template 4 is erected, and a guide pipe 5 is installed on the drilling template 4 for borehole positioning. After drilling, the borehole is flushed with high-pressure air and clean water to ensure that rock powder residue is ≤5cm. In this embodiment, a template 9.15m long and with legs 1.0m high is erected using Φ48 steel pipes. The guide pipe 5 is adapted to vertical / oblique angles. After measurement and verification, the borehole position deviation is ≤15mm and the angle deviation is ≤2°.

[0018] like Figure 3 As shown, in a preferred embodiment, in step S3, the amount of explosive is weighed according to the difference between the vertical blast hole 1 and the inclined blast hole 2, and the explosive is continuously and evenly coated and wrapped around the detonating cord and the inner wall of the PVC duct energy-conducting tube 3 to form a gapless explosive layer.

[0019] In this embodiment, the PVC shaped charge tubes 3 are cut to lengths of 1.55m and 1.63m respectively, according to the type of borehole, to match the vertical blast hole 1 and the inclined blast hole 2. The detonating cord is centrally placed in the PVC shaped charge tube 3. The emulsion explosive is heated to a plastic state and evenly coated onto the detonating cord and the inner wall of the trough, forming a gapless explosive layer (3-5mm thick). The length of the detonating cord extending 5-8cm from both ends of the PVC shaped charge tube 3 facilitates detonation. The explosive charge is controlled according to the actual depth of each borehole, with a standard charge of 80g / m for vertical blast holes and 70g / m for inclined blast holes. Continuous charging reduces energy diffusion, resulting in a detonation fracture depth ≤5cm, a 60% reduction compared to traditional methods. The rock mass integrity coefficient Kv ≥ 0.85, reducing the risk of rockburst. By using the prefabricated shaped charge tube and continuous charging process, the charging time for a single borehole is reduced to 6-8 minutes, which is 40% faster than the traditional interval charging. Moreover, the cost of the PVC wire trough shaped charge tube is only 1 / 5 of that of the metal shaped charge tube. It can be cut as needed and is highly adaptable. The digital electronic detonator can be repeatedly recycled, reducing the overall construction cost by 25%.

[0020] In a preferred embodiment, in step S3, the gunning clay is a mixture of clay and sand. In this embodiment, the gunning clay is a mixture of clay and sand, and the moisture content is maintained at 15%~20%.

[0021] In practical construction, this invention is carried out according to the following steps: 1. Construction preparation and parameter design Geological exploration and preliminary parameter determination: The integrity of the surrounding rock of the crane beam on the rock wall was investigated, and the types of smooth blasting holes were determined to be vertical smooth blasting holes (hole depth 1.55m) and inclined smooth blasting holes (hole depth 1.63m), with a uniform hole diameter of 42mm and hole spacing of 30cm.

[0022] Materials and equipment preparation: Select PVC cable trays to make shaped charge tubes to form PVC cable tray shaped charge tube 3 (wall thickness 3~5mm, groove width 25~30mm), Ø32mm rock emulsion explosive, detonating cord with diameter ≥5mm, high-precision digital electronic detonator (detonation time difference ≤1ms) and centralized controller; equipped with YT-28 hand drill, high-precision electronic scale (accuracy ±0.1g), angle ruler (accuracy ±0.5°).

[0023] Template erection: A two-way positioning template is erected using Φ48 steel pipes, with guide tubes (60cm long) and limiters installed to control hole position deviation ≤20mm and drilling angle deviation ≤3°. The template is fixed by anchor bars and diagonal braces, with a horizontal deviation ≤2mm / m.

[0024] 2. Pre-fabrication of shaped charge tubes and precision charging Energy-concentrating tube cutting: Cut PVC cable trays according to the type of blast hole. The length is 1.55m for vertical blast holes and 1.63m for inclined blast holes. The slot opening faces the excavation outline.

[0025] Accurate charge calculation: Measure the actual depth of each borehole, calculate the charge per borehole according to the linear charge density (80g / m for vertical boreholes and 70g / m for inclined boreholes), and weigh it using an electronic scale with an error of ≤±5%.

[0026] Continuous charge forming: The detonating cord is placed in the center of the PVC trough. The emulsion explosive is heated to a ductile state and continuously and evenly coated to wrap the detonating cord and the inner wall of the trough, forming a gapless explosive layer (thickness 3~5mm). The two ends of the detonating cord extend 5~8cm beyond the shaped charge tube.

[0027] 3. Two-way light blasting drilling and hole cleaning Drilling positioning: Position the holes according to the guide tube of the template, drill vertical blasting holes and inclined blasting holes in sections, set standard holes at the beginning and end, use a string line to control the uniformity of hole spacing, and use an angle ruler to correct the angle of the drill rod during the drilling process.

[0028] Combined hole cleaning: After drilling is completed, high-pressure air (pressure ≥ 0.6 MPa) + water are used alternately to clean the hole, ensuring that the thickness of residual rock powder in the hole is ≤ 5 cm and that there are no protruding debris on the hole wall.

[0029] 4. Installation of the energy-concentrating tube and sealing of the orifice Precise installation: Slowly push the prefabricated shaped charge tube into the blast hole, ensuring that the groove faces the excavation contour surface, and the alignment error between the two ends of the shaped charge tube and the blast hole port is ≤3cm.

[0030] Layered sealing: First, set a rubber sealing plug (40mm in diameter and 10cm in length) at the end of the energy-concentrating tube to fix the position, then fill it with self-made blasting mud (clay + sand, moisture content 15%~20%), with a sealing length ≥30cm and tamping it down.

[0031] 5. Precise detonation and effect verification Detonation network connection: Connect the digital electronic detonator to the detonating cord, use a centralized controller to set the detonation sequence, and ensure that the detonation time difference between adjacent boreholes is ≤1ms to avoid vibration superposition.

[0032] Safe detonation: After clearing the blasting area and confirming that no personnel remain, activate the central controller to detonate.

[0033] Effect testing: After blasting, test the flatness of the rock platform (error ≤10cm), half-hole ratio (≥90%), blast fracture depth (≤5cm), and over-excavation (≤15cm). If the standards are not met, adjust the linear charge density and retest.

[0034] 6. Zonal construction and parameter optimization Construction is carried out in 3.0m sections. The first section uses a linear charge density of 80g / m for vertical holes and 70g / m for inclined holes. Subsequent sections can be finely adjusted (50~80g / m) according to the integrity of the surrounding rock.

[0035] Establish a model corresponding to "linear charge density - blasting effect" to adapt to different rock mass integrity scenarios and guide subsequent construction.

[0036] The present invention has the following beneficial effects: 1. Significant energy-concentrating and directional effects: The PVC cable trough energy-concentrating pipe guides the detonation energy to be released along the excavation contour surface, and the flatness error of the rock platform is ≤10cm, which is 30% higher than the traditional method; the half-hole rate reaches 90%~95%, which meets the requirements of DL / T5198-2013 specification.

[0037] 2. Significantly reduced damage to surrounding rock: Continuous charging reduces energy diffusion, detonation fracture depth is ≤5cm, which is 60% less than traditional methods, and the rock mass integrity coefficient Kv≥0.85, reducing the risk of rockburst.

[0038] 3. High parameter controllability: By accurately calculating the amount of chemicals and strictly controlling the drilling accuracy, the over-excavation is ≤8cm, which is far better than the standard limit of 15cm, reducing the amount of subsequent repair work.

[0039] 4. Improved construction efficiency: The prefabricated shaped charge tube and continuous charging process shortens the charging time of a single borehole to 6-8 minutes, which is 40% faster than the traditional interval charging; the zoned construction and parameter model reuse shorten the test cycle by 30%.

[0040] 5. Good cost-effectiveness: The cost of PVC cable trays is only 1 / 5 of that of metal energy-concentrating tubes. They can be cut as needed, have strong adaptability, and digital electronic detonators can be recycled and reused, reducing the overall construction cost by 25%.

[0041] The terms "connection" and "fixing" appearing in the description of this invention can refer to fixed connection, processing and forming, welding, or mechanical connection. The specific meaning of the above terms in this invention should be understood according to the specific circumstances.

[0042] In the description of this invention, the terms "center," "upper," "lower," "horizontal," "inner," and "outer," etc., are used only to indicate the orientation or positional relationship for the convenience of describing this invention and to simplify the description, and do not indicate or imply a specific orientation that the device or element referred to must have, and therefore should not be construed as a limitation of this invention.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for constructing rock face crane beams using focused blasting, characterized in that: Includes the following steps; Step S1: Prepare for construction, survey the integrity of the surrounding rock, and determine the location of the vertical blasting hole (1) and the inclined blasting hole (2); Step S2: Drill and clean the holes toward the vertical blasting hole (1) and the inclined blasting hole (2); Step S3: Push the PVC cable tray energy-concentrating tube (3) into the vertical blast hole (1) and the inclined blast hole (2), with the groove opening facing the excavation outline, and use blasting mud to seal the vertical blast hole (1) and the inclined blast hole (2).

2. The method for constructing a rock wall crane beam using focused blasting, as described in claim 1, is characterized in that: In step S2, a drilling template (4) is set up, and a guide tube (5) is set on the drilling template (4) for blast hole positioning. After drilling with a drilling machine, the hole is rinsed with high-pressure air and clean water so that the rock powder residue is ≤5cm.

3. The method for constructing a rock wall crane beam using focused blasting, as described in claim 1, is characterized in that: In step S3, the amount of explosive is weighed according to the difference between vertical blast hole (1) and inclined blast hole (2), and the explosive is continuously and evenly coated to wrap the detonating cord and the inner wall of PVC duct energy-conducting tube (3) to form a gapless explosive layer.

4. The method for constructing a rock wall crane beam using focused blasting as described in claim 1, characterized in that: In step S3, the gunning mud is a mixture of clay and sand.

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