Damping presplitting system for rock drilling of mine shaft in water-rich karst area and operation method

Abstract

The invention discloses a damping presplitting system for rock drilling of a mine shaft in a water-rich karst area and an operation method. The system comprises an internal main blasting circular area, and a pre-splitting blasting annular area, a peripheral damping annular area and a karst grouting annular area sequentially surround the outer side of the internal main blasting circular area; the internal main blasting circular area comprises a central slotting hole, peripheral slotting holes and main blasting auxiliary holes; presplitting holes are formed in the presplitting blasting annular area, and outer ring damping holes and inner ring damping holes are formed in the peripheral damping annular area; the hole depth, the hole diameter, the hole pitch, the explosive loading structure, the explosive loading amount and the like of each area of the system are specifically set; the operation method comprises the steps that the pre-splitting holes, the peripheral slotting holes and the main blasting auxiliary holes are sequentially detonated, and finally residual stones in the peripheral damping annular area are chiseled away for forming. Vibration can be effectively controlled, and the vibration speed of blasting mass points is reduced by 40%-60%; water and mud inrush disasters are avoided through precise explosion control; and economical and efficient construction can be achieved, the supplementary grouting cost is reduced, and the construction period is shortened by 15%-30%.

Description

Technical Field

[0001] The invention relates to the technical field of shock-absorbing pre-cracking for rock drilling in a mine shaft in a water-rich karst area, and in particular to a shock-absorbing pre-cracking system for rock drilling in a mine shaft in a water-rich karst area and an operation method thereof. Background Art

[0002] As shallow mineral resources gradually become depleted, deep ore mining has become an inevitable trend. Mine shaft construction often passes through water-rich karst strata, which have the following significant characteristics: (1) Strong karst development: The dense distribution of caves and dissolution fissures leads to significant anisotropy of rock strength. Conventional blasting easily causes disorderly diffusion of energy, resulting in over-excavation and under-excavation.

[0003] (2) Frequent groundwater activity: The aquifer is connected to the karst pipeline. The dynamic load at the moment of blasting can easily induce sudden water and mud disasters. According to statistics, more than 70% of safety accidents during well construction in water-rich karst areas are caused by sudden water and mud.

[0004] (3) Poor self-stabilization ability of surrounding rock: Dissolution reduces the integrity of the rock mass. When the blasting vibration wave is transmitted to the surrounding rock, it is easy to trigger secondary collapse, threatening the safety of construction workers.

[0005] At present, the main blasting construction technologies for wellbore in water-rich karst areas are ordinary pre-splitting blasting and shock-absorbing interval charging. Ordinary pre-splitting blasting is to form a seismic isolation zone through pre-splitting holes to reduce the impact of the vibration of the main blasting area on the surrounding rock; shock-absorbing interval charging is to use air spacers to divide the charging sections to reduce the amount of explosives in a single section. However, the above technologies have the following limitations: (1) Traditional blasting in karst areas uses full-section drilling and charging. The blast stress wave acts directly on the grouting body, which can easily cause the grouting stone body to crack and the cave to penetrate, causing water gushing and mud bursting; (2) Conventional shock-absorbing holes are arranged in only a single row, which cannot effectively block the propagation of shock waves to the grouting area; (3) Severe over-excavation after blasting requires frequent grouting, delaying the construction period; In order to solve the above problems, a shock-absorbing pre-cracking system and an operating method for rock drilling in a mine shaft in a water-rich karst area are now proposed. Summary of the invention

[0006] In order to solve the above problems, a shock-absorbing pre-cracking system for rock drilling in a mine shaft in a water-rich karst area is provided.

[0007] The specific scheme of the present invention is: a shock-absorbing pre-splitting system for rock drilling in a mine shaft in a water-rich karst area, comprising an inner main blasting circular area, the inner main blasting circular area is a cylindrical area extending from top to bottom, and the outer side of the inner main blasting circular area is sequentially surrounded by a pre-splitting blasting annular area, a peripheral shock-absorbing annular area, and a karst grouting annular area; The pre-splitting blasting annular zone is arranged outside the inner main blasting circular zone and is adjacent to it. A plurality of pre-splitting holes arranged in an annular manner are arranged in the pre-splitting blasting annular zone. The pre-splitting holes are charge holes, and the hole depth of the pre-splitting holes is the blasting depth L. The charge holes are holes for loading explosives.

[0008] The inner main explosion circular area includes: a central slot hole, which is a single hole set at the center of the inner main explosion circular area, the hole depth of the central slot hole is 1.2 times of the blasting depth L, and the central slot hole is an empty hole, and a plurality of peripheral slot holes are symmetrically arranged around the inner slot hole; a plurality of main explosion auxiliary holes are evenly arranged outside the peripheral slot hole, and the hole depth of the main explosion auxiliary holes is the blasting depth L; the peripheral slot holes and the main explosion auxiliary holes are both charge holes, and both adopt segmented charging; The outer shock-absorbing annular zone is arranged outside the pre-splitting blasting annular zone and is arranged adjacent to it. The outer shock-absorbing annular zone is provided with a plurality of outer ring shock-absorbing holes and inner ring shock-absorbing holes arranged in an annular manner. The hole depths of the outer ring shock-absorbing holes and the inner ring shock-absorbing holes are both 1.2 times of the blasting depth L. The outer ring shock-absorbing holes are filled with flexible damping materials; the inner ring shock-absorbing holes are located inside the outer ring shock-absorbing holes, and the inner ring shock-absorbing holes are empty holes. The karst grouting annular area is arranged outside the peripheral shock-absorbing annular area and is arranged adjacent to the peripheral shock-absorbing annular area.

[0009] Furthermore, the annular width B1 of the peripheral shock-absorbing annular zone is L, and the annular width B2 of the pre-splitting blasting annular zone is 1 / 2L.

[0010] Furthermore, the connection between the outer shock-absorbing annular zone and the karst grouting annular zone is the wellbore excavation contour line, the distance between the outer circle shock-absorbing holes and the wellbore excavation contour line is 0.2-0.4m, the aperture of the outer circle shock-absorbing holes is 100-120mm, and the hole spacing is 0.3~0.5m; the distance between the inner circle shock-absorbing holes and the outer edge of the pre-splitting blasting annular zone is 0.3-0.5m, the aperture of the inner circle shock-absorbing holes is 50-60mm, and the hole spacing is 0.6-1.0m.

[0011] Furthermore, the pre-splitting holes are arranged on the annular center line of the pre-splitting blasting annular zone, the aperture of the pre-splitting holes is 50-60 mm, and the hole spacing is 0.4-0.6 m.

[0012] Furthermore, the diameter of the central groove hole is 100-120mm, and the hole depth is 1.2 times the blasting depth L; there are four peripheral groove holes, which are symmetrically arranged at a spacing of 0.4-0.6m. The diameter of the peripheral groove holes is 50-60mm, and the hole depth is 1.2 times the blasting depth L; the main blasting auxiliary holes are evenly distributed in a ring shape on the outside of the peripheral groove holes with a mesh density of 0.5-0.8m×0.5-0.8m. The diameter of the main blasting auxiliary holes is 40-60mm, and the hole depth is the blasting depth L.

[0013] Furthermore, the pre-splitting hole adopts an air-spaced charge structure, and the charge density is 0.2-0.4 Kg / m.

[0014] Furthermore, the peripheral slot holes and the main blast auxiliary holes adopt segmented charging in the holes, with the upper charging accounting for 30% and the lower charging accounting for 70%.

[0015] Furthermore, the charge density of the peripheral cut holes and the main blast auxiliary holes is determined according to the rock Proctor coefficient.

[0016] An operating method for shock-absorbing pre-splitting of rock drilling in a mine shaft in a water-rich karst area, the method is applied to the shock-absorbing pre-splitting system for rock drilling in a mine shaft in a water-rich karst area as described above, and the operating method comprises the following steps: S1: Detonate pre-crack holes, with a delay of 0ms between holes; S2: Detonate the surrounding slot holes, with a time difference of 50~100ms from S1, and a time delay of 25~50ms between holes; S3: Detonate the auxiliary hole for main blasting, with a time difference of 50~100ms from S2, and a time delay of 25~50ms between holes; S4: Shaft section is formed. After the main blast auxiliary hole 7 is detonated and passes the safety inspection, a pneumatic rock drill is used to drill away the residual rocks in the outer shock-absorbing annular area to form the final shaft section.

[0017] The present invention has the following beneficial effects: 1. Vibration control: The peripheral shock-absorbing annular area and the pre-splitting blasting annular area can reduce the vibration speed of the blasting particles by 40%~60%, reducing the impact of blasting on the karst grouting body; 2. Precise blasting control: The combination of zoned micro-difference blasting and empty hole guidance technology is used to avoid the penetration of karst grouting bodies, which would lead to the connection between the aquifer and the karst pipeline, thus causing water and mud inrush disasters, thus ensuring the safety of construction; ‌3. Economical and efficient‌: Reduce the cost of grouting and shorten the construction period by 15%~30% during use, greatly saving economic costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a front view schematic diagram of the present invention; Figure 2 It is a cross-sectional structural schematic diagram of the present invention; In the figure: 1. Internal main blasting circular area; 101. Center slot hole; 102. Peripheral slot holes; 103. Main blasting auxiliary holes; 2. Pre-splitting blasting annular area; 201. Pre-splitting holes; 3. External shock-absorbing annular area; 301. Outer circle shock-absorbing holes; 302. Inner circle shock-absorbing holes; 4. Karst grouting annular area; 5. Shaft excavation contour line. DETAILED DESCRIPTION

[0019] Please refer to Figure 1-Figure 2 , A shock-absorbing pre-splitting system for rock drilling in a water-rich karst area mine shaft, comprising an inner main blasting circular area 1, the inner main blasting circular area 1 is a cylindrical area extending from top to bottom, and the outer side of the inner main blasting circular area 1 is sequentially surrounded by a pre-splitting blasting annular area 2, an outer shock-absorbing annular area 3, and a karst grouting annular area 4; The pre-splitting blasting annular area 2 is arranged outside the inner main blasting circular area 1 and is adjacent to it. A plurality of pre-splitting holes 201 arranged in an annular manner are arranged in the pre-splitting blasting annular area 2. The pre-splitting holes 201 are charge holes, and the hole depth of the pre-splitting holes 201 is the blasting depth L; wherein the charge holes are holes for loading explosives.

[0020] The inner main explosion circular area 1 comprises: a central slotted hole 101, which is a single hole arranged at the center of the inner main explosion circular area 1, and the hole depth of the central slotted hole 101 is 1.2 times of the blasting depth L, and the central slotted hole 101 is an empty hole, and a plurality of peripheral slotted holes 102 are symmetrically arranged around the inner slotted hole; a plurality of main explosion auxiliary holes 103 are evenly arranged outside the peripheral slotted hole 102, and the hole depth of the main explosion auxiliary hole 103 is the blasting depth L; the peripheral slotted holes 102 and the main explosion auxiliary holes 103 are both charge holes, and both adopt segmented charge; The outer shock-absorbing annular zone 3 is arranged outside the pre-splitting blasting annular zone 2 and is arranged adjacent thereto. The outer shock-absorbing annular zone 3 is provided with a plurality of outer ring shock-absorbing holes 301 and inner ring shock-absorbing holes 302 arranged in an annular manner. The hole depths of the outer ring shock-absorbing holes 301 and the inner ring shock-absorbing holes 302 are both 1.2 times of the blasting depth L. The outer ring shock-absorbing holes 301 are filled with flexible damping materials; the inner ring shock-absorbing holes 302 are located inside the outer ring shock-absorbing holes 301 and are empty holes. The karst grouting annular area 4 is arranged outside the peripheral shock-absorbing annular area 3 and is arranged adjacent to it.

[0021] In this embodiment, the annular width B1 of the peripheral shock-absorbing annular zone 3 is L, and the annular width B1 of the pre-splitting blasting annular zone 2 is 1 / 2L.

[0022] In this embodiment, the connection between the outer shock-absorbing annular zone 3 and the karst grouting annular zone 4 is the shaft excavation contour line 5, the distance between the outer ring shock-absorbing holes 301 and the shaft excavation contour line 5 is 0.2-0.4m, the aperture of the outer ring shock-absorbing holes 301 is 100-120mm, and the hole spacing is 0.3~0.5m; the distance between the inner ring shock-absorbing holes 302 and the outer edge of the pre-splitting blasting annular zone 2 is 0.3-0.5m, the aperture of the inner ring shock-absorbing holes 302 is 50-60mm, and the hole spacing is 0.6-1.0m.

[0023] In this embodiment, the pre-splitting holes 201 are arranged on the annular center line of the pre-splitting blasting annular zone 2, the aperture of the pre-splitting holes 201 is 50-60 mm, and the hole spacing is 0.4-0.6 m.

[0024] In this embodiment, the aperture of the central slot hole 101 is 100-120 mm, and the hole depth is 1.2 times the blasting depth L; there are four peripheral slot holes 102, which are symmetrically arranged at a spacing of 0.4-0.6 m. The aperture of the peripheral slot holes 102 is 50-60 mm, and the hole depth is 1.2 times the blasting depth L; the main blasting auxiliary holes 103 are evenly distributed in a ring shape on the outside of the peripheral slot holes 102 at a mesh density of 0.5-0.8 m×0.5-0.8 m. The aperture of the main blasting auxiliary holes 103 is 40-60 mm, and the hole depth is the blasting depth L.

[0025] In this embodiment, the pre-crack hole 201 adopts an air-spaced charge structure, and the charge density is 0.2-0.4 Kg / m.

[0026] In this embodiment, the peripheral cutout holes 102 and the main explosion auxiliary holes 103 adopt segmented charging in the holes, with the upper charging accounting for 30% and the lower charging accounting for 70%.

[0027] In this embodiment, the charge density of the peripheral cutout holes 102 and the main blast auxiliary holes 103 is determined according to the rock Proctor coefficient.

[0028] An operating method for shock-absorbing pre-splitting of rock drilling in a mine shaft in a water-rich karst area, the method is applied to the shock-absorbing pre-splitting system for rock drilling in a mine shaft in a water-rich karst area as described above, and the operating method comprises the following steps: S1: Detonate pre-crack hole 201, delay between holes 0ms; S2: Detonate the surrounding cutout holes 102, with a time difference of 50~100ms from S1, and a time delay of 25~50ms between holes; S3: detonate the auxiliary main explosion hole 103, with a time difference of 50~100ms from S2, and a time delay of 25~50ms between holes; S4: Shaft section is formed. After the main blast auxiliary hole 1037 is detonated and passes the safety inspection, a pneumatic rock drill is used to drill away the remaining rocks in the outer shock-absorbing annular area 3 to form the final shaft section.

Claims

1. A shock-absorbing pre-cracking system for rock drilling in a water-rich karst area mine shaft, comprising an internal main blast circular area, the internal main blast circular area being a cylindrical area extending from top to bottom, characterized in that: The outer side of the inner main blasting circular area is surrounded in sequence by a pre-splitting blasting annular area, an outer shock-absorbing annular area, and a karst grouting annular area; The pre-splitting blasting annular area is arranged outside the inner main blasting circular area and adjacent thereto. A plurality of pre-splitting holes arranged in an annular manner are arranged in the pre-splitting blasting annular area. The pre-splitting holes are charge holes, and the hole depth of the pre-splitting holes is the blasting depth L. The inner main explosion circular area includes: a central slot hole, which is a single hole set at the center of the inner main explosion circular area, the hole depth of the central slot hole is 1.2 times of the blasting depth L, and the central slot hole is an empty hole, and a plurality of peripheral slot holes are symmetrically arranged around the inner slot hole; a plurality of main explosion auxiliary holes are evenly arranged outside the peripheral slot hole, and the hole depth of the main explosion auxiliary holes is the blasting depth L; the peripheral slot holes and the main explosion auxiliary holes are both charge holes, and both adopt segmented charging; The outer shock-absorbing annular zone is arranged outside the pre-splitting blasting annular zone and is arranged adjacent to it. The outer shock-absorbing annular zone is provided with a plurality of outer ring shock-absorbing holes and inner ring shock-absorbing holes arranged in an annular manner. The hole depths of the outer ring shock-absorbing holes and the inner ring shock-absorbing holes are both 1.2 times of the blasting depth L. The outer ring shock-absorbing holes are filled with flexible damping materials; the inner ring shock-absorbing holes are located inside the outer ring shock-absorbing holes, and the inner ring shock-absorbing holes are empty holes. The karst grouting annular area is arranged outside the peripheral shock-absorbing annular area and is arranged adjacent to the peripheral shock-absorbing annular area.

2. The shock-absorbing pre-cracking system for rock drilling in a water-rich karst area mine shaft according to claim 1 is characterized by: The annular width B1 of the peripheral shock-absorbing annular zone is L, and the annular width B2 of the pre-splitting blasting annular zone is 1 / 2L.

3. The shock-absorbing pre-cracking system for rock drilling in a water-rich karst area mine shaft according to claim 1 is characterized by: The connection between the outer shock-absorbing annular zone and the karst grouting annular zone is the wellbore excavation contour line, the distance between the outer circle shock-absorbing holes and the wellbore excavation contour line is 0.2-0.4m, the aperture of the outer circle shock-absorbing holes is 100-120mm, and the hole spacing is 0.3~0.5m; the distance between the inner circle shock-absorbing holes and the outer edge of the pre-splitting blasting annular zone is 0.3-0.5m, the aperture of the inner circle shock-absorbing holes is 50-60mm, and the hole spacing is 0.6-1.0m.

4. The shock-absorbing pre-cracking system for rock drilling in a water-rich karst area mine according to claim 1 is characterized by: The pre-splitting holes are arranged on the annular center line of the pre-splitting blasting annular zone, the aperture of the pre-splitting holes is 50-60 mm, and the hole spacing is 0.4-0.6 m.

5. The shock-absorbing pre-cracking system for rock drilling in a water-rich karst area mine shaft according to claim 1 is characterized by: The diameter of the central slot hole is 100-120mm, and the hole depth is 1.2 times the blasting depth L; there are four peripheral slot holes, which are symmetrically arranged at a spacing of 0.4-0.6m. The diameter of the peripheral slot holes is 50-60mm, and the hole depth is 1.2 times the blasting depth L; the main blasting auxiliary holes are evenly distributed in a ring shape on the outside of the peripheral slot holes with a mesh density of 0.5-0.8m×0.5-0.8m. The diameter of the main blasting auxiliary holes is 40-60mm, and the hole depth is the blasting depth L.

6. The shock-absorbing pre-cracking system for rock drilling in a water-rich karst area mine shaft according to claim 1 is characterized by: The pre-splitting hole adopts an air-spaced charge structure, and the charge density is 0.2-0.4 Kg / m.

7. The shock-absorbing pre-cracking system for rock drilling in a water-rich karst area mine according to claim 1 is characterized by: The peripheral cutting holes and the main blasting auxiliary holes are charged in sections, with the upper charge accounting for 30% and the lower charge accounting for 70%.

8. The shock-absorbing pre-cracking system for rock drilling in a water-rich karst area mine shaft according to claim 1 is characterized by: The charge density of the peripheral cutting holes and the main blasting auxiliary holes is determined according to the rock Proctor coefficient.

9. A method for shock-absorbing pre-cracking in rock drilling in a water-rich karst area mine shaft, characterized by: The method is applied to the vibration reduction pre-cracking system for rock drilling in a water-rich karst area mine shaft as described in any one of claims 1 to 8, and the operation method comprises the following steps: S1: Detonate pre-crack holes, with a delay of 0ms between holes; S2: Detonate the surrounding slot holes, with a time difference of 50~100ms from S1, and a time delay of 25~50ms between holes; S3: Detonate the auxiliary hole for main blasting, with a time difference of 50~100ms from S2, and a time delay of 25~50ms between holes; S4: Shaft section is formed. After the main blast auxiliary hole 7 is detonated and passes the safety inspection, a pneumatic rock drill is used to drill away the residual rocks in the outer shock-absorbing annular area to form the final shaft section.

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