Blasting method for reducing pipe shed support damage and charging device and explosive package structure

Abstract

The present invention discloses a blasting method and a charging device and an explosive bag structure for reducing damage to pipe shed support, belonging to the technical field of tunnel blasting construction, including: setting a pre-splitting zone near the bottom of the pipe shed on the face, setting a plurality of blastholes on the pre-splitting zone, and detonating the explosives after filling the blastholes with explosives; then setting a plurality of blastholes near the bottom of the pre-splitting zone on the face, and detonating the explosives after filling the blastholes with explosives; then setting a plurality of blastholes on the blasting surface between the middle of the face and the bottom of the pre-splitting zone, and detonating the explosives after filling the blastholes with explosives; then setting a plurality of blastholes near the bottom of the face below the middle of the face, and detonating the explosives after filling the blastholes with explosives. This scheme adopts the scheme of pre-splitting and polishing blasting, and can perform pre-splitting blasting below the pipe shed before slotting blasting to form pre-cracks, reduce the propagation of slotting blasting vibration, and thus reduce damage to the pipe shed.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel blasting construction, and in particular to a blasting method for reducing pipe shed support damage, a charging device and an explosive package structure. Background Art

[0002] The focus of highway and railway engineering construction has gradually shifted to the western mountainous areas. During the construction process, many soft rocks are encountered. Soft rock is the most common unfavorable geological condition in tunnel construction and an important factor affecting the stability of tunnel surrounding rock. Normally, soft rock is in a stable state. When affected by external forces such as blasting and excavation, the stability of soft rock will be destroyed, resulting in engineering accidents such as landslides and roof falls. Therefore, soft rock brings great difficulties to tunnel construction.

[0003] Among the many tunnel construction methods (shield, TBM, open cut, semi-open cut, etc.), the drilling and blasting method occupies the most important position in the tunnel construction process due to its lower cost and higher excavation efficiency.

[0004] However, in the case of soft rock, advance support is required before tunnel excavation. Therefore, during the drilling and blasting process, the blasting vibration must be controlled to reduce damage to the advance support.

[0005] The existing drilling and blasting method is used to construct soft rock tunnels, which has a great impact on the vibration of the support and is easy to cause damage to the support. Summary of the invention

[0006] On the one hand, in order to solve the problems of the prior art, the present invention provides a method for reducing blasting damage of tunnel pipe support, comprising:

[0007] Step 1, blasting of pre-splitting zone:

[0008] A pre-splitting zone is arranged on the tunnel face near the bottom of the pipe shed, a plurality of blast holes are arranged on the pre-splitting zone, and explosives are filled in the blast holes and then detonated;

[0009] Step 2, arc-shaped pilot pit blasting:

[0010] A plurality of blast holes are arranged on the tunnel face close to the bottom of the pre-splitting zone, and explosives are filled in the blast holes and then detonated; wherein the blast holes are in an arc shape as a whole;

[0011] Step 3: Reserve core soil for blasting:

[0012] A plurality of blast holes are arranged on the blasting surface between the middle of the tunnel face and below the pre-splitting zone, and the blast holes are filled with explosives and then detonated;

[0013] Step 4, blast down the stairs:

[0014] A plurality of blast holes close to the bottom of the tunnel face are arranged below the middle of the tunnel face, and the explosives are detonated after being filled in the blast holes.

[0015] Furthermore, guide slits are arranged on both sides of the blasthole in the pre-splitting zone, and the guide slits are arranged on both sides of the tunnel contour line.

[0016] Furthermore, the blastholes in step 2 include: cutout holes, bottom plate holes, auxiliary holes and peripheral holes;

[0017] The cutouts are symmetrically distributed on the center line of the tunnel face;

[0018] The bottom plate eye is arranged around the bottom edge of the arc-shaped guide pit;

[0019] The peripheral eyes are arranged at the edges of both sides of the arc-shaped guide pit;

[0020] The auxiliary eyes are distributed above the bottom of the arc-shaped guide pit and are located around the groove eyes.

[0021] Furthermore, the explosive is an emulsion explosive, and blasting is achieved by connecting a digital electronic mine to an external controller.

[0022] On the other hand, the present solution provides a charge charging device, comprising: a fixing rod, a fixing ring and a plugging partition;

[0023] There are two fixing rods, and a plurality of explosive packages are arranged between the fixing rods;

[0024] The fixing rings are arranged at both ends of the medicine bag;

[0025] Both sides of the fixing ring are connected to the fixing rod on the same side;

[0026] The plugging partition is located above the explosive package, and two sides of the plugging partition are connected to the fixing rods on the same side.

[0027] On the other hand, the present invention provides an explosive package structure, the explosive package comprising: a left slit tube, a right slit tube and an energy-gathering cover;

[0028] The left slit tube and the right slit tube are combined to form a pipeline structure;

[0029] The energy gathering covers are provided with two, and the energy gathering covers are respectively connected to the inner walls of the left slit tube and the right slit tube;

[0030] Wherein, the pipe is filled with emulsion explosive located between the energy-gathering covers;

[0031] Both ends of the pipeline formed by the left slit tube and the right slit tube are connected with the fixing ring.

[0032] Furthermore, a plurality of slitting holes are vertically arranged on the left slitting tube and the right slitting tube, and the slitting holes are distributed in a straight line.

[0033] Furthermore, the energy gathering cover is V-shaped, and flanges are provided at the edges of both sides of the energy gathering cover; correspondingly, the inner walls of the left slit tube and the right slit tube are both provided with limiting grooves adapted to the flanges;

[0034] The energy gathering cover is connected to the left slitting tube and the right slitting tube by means of a clamping connection.

[0035] Furthermore, the left slitting tube is provided with a first groove and a first protrusion;

[0036] The first groove and the first protrusion are respectively located at the contact point between the left slit tube and the right slit tube;

[0037] Correspondingly, the right slit tube is provided with a second protrusion adapted to the first groove, and a second groove adapted to the first protrusion;

[0038] The left slit tube and the right slit tube are connected by a clamping method.

[0039] Beneficial effects of the present invention:

[0040] Directional blasting can be achieved by setting up the charging device and the charge bag structure in conjunction with the guide seam of the pre-cracked hole, while limiting the damage of blasting to other directions; the air medium interval charging changes the contact relationship between the charge column and the hole wall, and uses the material as a spacing medium to separate the explosive from the hole wall, reducing the initial pressure of the explosion wave acting on the hole wall, prolonging the effective action time of the explosion load, so that no crushing area is generated around the blast hole or the crushing area is significantly reduced, thereby improving the effective utilization rate of the explosive energy and achieving the purpose of improving the blasting and crushing effect. At the same time, the air medium also has a certain energy storage effect, storing part of the energy of the explosive explosion in the form of internal energy and kinetic energy in the gap air, and releasing it in the form of static pressure during the rock crushing process together with the detonation products, further strengthening the destructive effect of static pressure on the rock and forming a more uniform block.

[0041] In addition, by adopting the scheme of pre-splitting and polishing blasting, the present scheme can perform pre-splitting blasting under the pipe shed before the slotting blasting to form pre-cracks, reduce the propagation of slotting blasting vibration, and thus reduce damage to the pipe shed. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 It is a schematic diagram of the structure of the charge charging device provided by the present invention;

[0044] Figure 2 It is a schematic diagram of the plugging partition structure provided by the present invention;

[0045] Figure 3 It is a schematic diagram of the structure of the medicine package provided by the present invention;

[0046] Figure 4 It is a schematic diagram of the structure of the fixing ring provided by the present invention;

[0047] Figure 5 It is a schematic diagram of the structure of the energy gathering cover provided by the present invention;

[0048] Figure 6 It is a schematic diagram of the limit groove structure provided by the present invention;

[0049] Figure 7 It is a schematic diagram of the top view structure of the fixing ring provided by the present invention;

[0050] Figure 8 It is a schematic diagram of the blasting process provided by the present invention;

[0051] Fig. 9 It is a schematic diagram of the pre-splitting hole provided by the present invention;

[0052] Fig.10 It is a schematic diagram of blasthole distribution provided by the present invention.

[0053] Figure numerals: 1 is a medicine bag, 2 is a fixing rod, 3 is a fixing ring, 4 is a blocking partition, 5 is a left slit tube, 6 is a right slit tube, 7 is an energy gathering cover, 8 is a slit hole, 9 is a limiting groove, 10 is a first groove, 11 is a first protrusion, 12 is a second protrusion, and 13 is a second groove. DETAILED DESCRIPTION

[0054] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0055] The embodiment of the present invention is that Daliangshan No. 1 Tunnel is located in Dagudui Township, Leibo County, Sichuan Province. It is designed as a bidirectional separated mountain-crossing tunnel. The left tunnel entrance pile number is ZK73+594, the boundary mileage pile number is ZK80+500, and the total length is 6906m. The right tunnel entrance pile number is YK73+648, the boundary mileage pile number is YK80+500, and the total length is 6852m. The tunnel length of this section is large, the unfavorable geology is mainly soft surrounding rock, and the construction is difficult.

[0056] Embodiment 1:

[0057] See also Figures 1 to 7 , This solution provides a charge device, including: a fixing rod 2, a fixing ring 3 and a plugging partition 4;

[0058] There are two fixing rods 2, and a plurality of explosive packages 1 are fixedly arranged between the fixing rods 2;

[0059] The fixing rings are arranged at both ends of the explosive charge;

[0060] The surface of the fixing rod is provided with threads, and the two sides of the fixing ring 3 are symmetrically provided with penetrating mounting holes, and the fixing rod 2 passes through the mounting holes on both sides of the fixing ring 2 respectively, and the connection between the fixing rod and the fixing ring is achieved by screwing nuts on the fixing rod;

[0061] The plugging partition 4 is located above the explosive package 1, and both sides of the plugging partition 4 are fixedly connected to the fixing rod 2 on the same side. The outside of the explosive package is plugged with cannon mud, and the plugging partition is used to isolate the explosive package and the cannon mud.

[0062] The plugging partition 4 includes: a wire tube and a baffle;

[0063] The wire tube is inserted into the end face of the baffle; it is used to lead out the leg wire of the digital electronic detonator; through holes are provided on both sides of the baffle, wherein the fixing rod 2 passes through the through holes on both sides of the baffle respectively, and the connection between the baffle and the fixing rod is achieved by screwing a nut on the fixing rod.

[0064] Embodiment 2:

[0065] See also Figures 3 to 7 This scheme provides an explosive package structure, wherein the explosive package 1 comprises: a left slit tube 5, a right slit tube 6 and an energy-gathering cover 7;

[0066] The left slit tube 5 and the right slit tube 6 are integrally combined to form a pipeline structure; the pipeline is filled with emulsion explosives;

[0067] The energy-gathering covers 7 are provided with two, and the energy-gathering covers 7 are respectively engaged with the inner walls of the left slit tube 5 and the right slit tube 6; wherein the emulsion explosive is located between the energy-gathering covers;

[0068] Both ends of the pipeline formed by the left slit tube 5 and the right slit tube 6 are fixedly connected with the fixing ring 3 .

[0069] Among them, external threads are provided near both ends of the left slit tube and the right slit tube, and correspondingly, internal threads matching the external threads are provided on the inner ring surface of the fixing ring; the left slit tube and the right slit tube are connected to the fixing ring by means of screw connection.

[0070] In some implementations, the energy gathering cover 7 is V-shaped, and flanges are provided at both side edges of the energy gathering cover 7; correspondingly, limiting grooves 9 adapted to the flanges are provided on the inner walls of the left slitting tube 5 and the right slitting tube 6.

[0071] Wherein, the energy gathering cover is connected with the left slitting tube and the right slitting tube by means of a clamping connection.

[0072] The function of the energy-gathering hood is that when the explosion wave reaches the top of the metal hood, the high temperature and high pressure generated will squeeze and melt the metal hood axially at a very high speed. At this time, the metal hood forms a high-speed, high-density high-energy metal jet moving in the energy-gathering direction under the action of great pressure.

[0073] In some implementations, a plurality of slitting holes 8 are vertically disposed on the left slitting tube 5 and the right slitting tube 6 , and the slitting holes 8 are distributed in a straight line.

[0074] Among them, the role of the slit hole is to form a guiding effect when the formed metal jet rushes out from the prefabricated opening. The detonation products impact the air medium to form a shock wave, and the blast hole wall at the slit is continuously subjected to the high-speed, high-pressure metal jet to cause rupture, forming an initial crack. The detonation gas impacts the unopened part of the slit tube and reflects in the slit direction, strengthening the destructive effect in the slit direction and further expanding the crack.

[0075] In some implementations, the left slitting tube 5 is provided with a first groove 10 and a first protrusion 11;

[0076] The first groove 10 and the first protrusion 11 are respectively located at the contact point between the left slit tube 5 and the right slit tube 6;

[0077] Correspondingly, the right slit tube 6 is provided with a second protrusion 12 adapted to the first groove 10, and a second groove 13 adapted to the first protrusion 11;

[0078] The left slit tube 5 and the right slit tube 6 are connected by a clamping method.

[0079] When using the charging device, first connect the energy-gathering cover to the left and right slit tubes respectively, then fill the explosives into the combined left and right slit tubes, and finally fix the left and right slit tubes with fixing rings;

[0080] Then, according to the explosive interval designed for the pre-crack hole, fix the charge bag structure on the fixed rod with fixing screws, and finally pass the blocking partition through the fixed rod. After the digital detonator leg wire passes through the empty tube in the blocking partition, fix the partition with fixing nuts to carry out the blocking operation.

[0081] Embodiment 3:

[0082] See also Figures 8 to 10 , a method for reducing tunnel pipe support blasting damage, comprising: designing a blasting plan according to tunnel conditions, and then setting a pre-splitting area (first stage), an arc-shaped pilot pit area (second stage), a reserved core soil area (third stage) and a lower step area (fourth stage) on the tunnel face;

[0083] Then, the blasthole positions are measured and laid out in the pre-splitting area, arc-shaped pilot pit, reserved core soil and lower step in turn;

[0084] Next, drilling is performed at the blasthole location. After the blasthole construction is completed, the blasthole is inspected, repaired and cleaned. After confirming that the required requirements are met, explosives are filled in the blasthole and then the blasthole is blocked;

[0085] Then use the electronic digital detonator to connect with the detonator, and then connect to the detonation network to detonate the explosives;

[0086] Next, check the effect after blasting. If the effect is not ideal, adjust the blasting parameters according to the blasting effect. If the effect is ideal, proceed to the next cycle.

[0087] Among them, each area is blasted one by one according to the blasting parameters:

[0088] Specifically:

[0089] Step 1, blasting of pre-splitting zone:

[0090] A pre-splitting zone is set on the tunnel face near the bottom of the pipe shed, and a number of blastholes are set on the pre-splitting zone. After the blastholes are set, the depth and the hole wall of each hole are checked. Then, the emulsion explosive is installed on the charging device and the whole is placed in the blasthole. The network connection is checked using an electronic detonator encoder. After the connection is normal, the delay time is set for each hole.

[0091] Then, charge the detonator, press the detonation button, and detonate after charging is completed;

[0092] The overall shape of the pre-splitting zone is arc-shaped, and a distance is left between the two ends of the pre-splitting zone and the middle of the tunnel face.

[0093] Guide slits are symmetrically arranged on both sides of the blasthole (pre-splitting hole) in the pre-splitting zone. When drilling the blasthole, the blasthole dimensions are: blasthole depth 1.0m, blasthole diameter 42mm; the charge amount in each blasthole is 0.16kg.

[0094] When charging explosives in the blasthole in the pre-splitting zone, the charging device designed in the present application is used to charge the blasthole.

[0095] Step 2, arc-shaped pilot pit blasting:

[0096] A plurality of blastholes are arranged on the tunnel face close to the bottom of the pre-splitting zone. After the blastholes are set, the depth and the hole wall of each hole are checked, and then electronic digital detonators are filled in the blastholes. The network connection is checked by using an electronic detonator encoder. After the connection is normal, the delay time is set for each hole.

[0097] Then, charge the detonator, press the detonation button, and detonate after charging is completed;

[0098] The blasthole is in an arc shape as a whole, and comprises: a plurality of cutout holes, bottom plate holes, auxiliary holes and peripheral holes are respectively provided;

[0099] The groove holes are symmetrically distributed on the center line of the tunnel face; the groove holes are completed in the form of oblique groove holes;

[0100] The cutouts are arranged in three layers, and the top and bottom of the outermost cutouts are spaced from the bottom of the pre-splitting zone and the top of the reserved core soil respectively;

[0101] The first layer of the cutouts is located on the center line;

[0102] The second layer of cutouts are distributed around the first layer of cutouts, and the second layer of cutouts are symmetrically distributed on both sides of the center line, forming a square shape as a whole;

[0103] The third layer of cutouts are distributed around the second layer of cutouts, and the second layer of cutouts are symmetrically distributed on both sides of the center line, forming a rectangular shape as a whole;

[0104] The bottom plate eye is arranged around the bottom edge of the arc-shaped guide pit;

[0105] The peripheral eyes are arranged at the edges of both sides of the arc-shaped guide pit;

[0106] The auxiliary eyes are distributed above the bottom of the arc-shaped guide pit and are located around the groove eyes.

[0107] In addition, the peripheral eye and the auxiliary eye adopt a conventional uncoupled charging method, and the groove eye adopts a continuous charging method.

[0108] When drilling blastholes, the relevant dimensions are: the groove hole depth is 1.2m, the blasthole diameter is 42mm, and the single-hole charge is 0.3kg; the bottom plate hole, auxiliary hole and peripheral hole depths are all 1m, the blasthole diameters are all 42mm, and the single-hole charges are 0.3kg, 0.225kg and 0.16kg respectively.

[0109] Step 3: Reserve core soil for blasting:

[0110] A plurality of blast holes are arranged on the blasting surface between the middle of the tunnel face and the bottom of the pre-splitting zone. After the blast holes are set, the depth and the hole wall of each hole are checked, and then softened explosives are filled in the blast holes. The emulsion explosives are detonated by electronic digital detonators.

[0111] Specifically, an electronic detonator encoder is used to check the network connection, and after the connection is normal, the delay time is set hole by hole;

[0112] Then, charge the detonator, press the detonation button, and detonate after charging is completed;

[0113] The reserved core soil for blasting is in the shape of an isosceles trapezoid as a whole, and the blastholes arranged thereon are excavation holes.

[0114] The blasthole is an excavation hole. When the blasthole is drilled, the hole depth of the excavation hole is 1m and the single hole charge is 0.19kg.

[0115] Step 4, blast down the stairs:

[0116] A plurality of blastholes are arranged below the middle of the tunnel face and close to the bottom of the tunnel face. After the blastholes are drilled, the depth and the wall of each hole are checked, and then softened explosives are filled in the blastholes. The emulsion explosives are detonated by electronic digital detonators.

[0117] Specifically, an electronic detonator encoder is used to check the network connection, and after the connection is normal, the delay time is set hole by hole;

[0118] Then, charge the detonator, press the detonation button, and detonate after charging is completed;

[0119] The blasthole is a tunneling hole. When drilling the blasthole, the hole depth of the tunneling hole is 1m and the charge per hole is 0.19kg. In order to optimize the blasting parameters, when blasting at the face, a three-phase velocity sensor is set on the surface directly above the face to collect the vibration velocity after blasting. If the vibration velocity is fast, the blasting design is optimized.

[0120] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A charging device, characterized in that: include: Retaining rods, retaining rings and plugging spacers; There are two fixing rods, and a plurality of explosive packages are arranged between the fixing rods; The fixing rings are arranged at both ends of the explosive charge; Both sides of the fixing ring are connected to the fixing rod on the same side; The plugging partition is located above the explosive charge, and two sides of the plugging partition are connected to the fixing rods on the same side; The explosive charge comprises: a left slit tube, a right slit tube and an energy-gathering cover; The left slit tube and the right slit tube are combined to form a pipeline structure; The energy gathering covers are provided with two, and the energy gathering covers are respectively connected to the inner walls of the left slit tube and the right slit tube; Wherein, the pipe is filled with emulsion explosive located between the energy-gathering covers; The left slit tube and the right slit tube are vertically provided with a plurality of slit holes penetrating therethrough, and the slit holes are distributed in a straight line; The energy gathering cover is V-shaped, and flanges are provided at the edges of both sides of the energy gathering cover; correspondingly, the inner walls of the left slit tube and the right slit tube are both provided with limiting grooves adapted to the flanges; The energy gathering cover is connected to the left slit tube and the right slit tube by means of a clamping connection; The left slitting tube is provided with a first groove and a first protrusion; The first groove and the first protrusion are respectively located at the contact point between the left slit tube and the right slit tube; Correspondingly, the right slit tube is provided with a second protrusion adapted to the first groove, and a second groove adapted to the first protrusion; The left slit tube and the right slit tube are connected by a clamping method.

2. A method for reducing blasting damage to tunnel pipe-roof support, using the charging device according to claim 1 to blast the tunnel pipe-roof support, characterized in that: include: Step 1, blasting of pre-splitting zone: A pre-splitting zone is arranged on the tunnel face near the bottom of the pipe shed, a plurality of blast holes are arranged on the pre-splitting zone, and explosives are filled in the blast holes and then detonated; Step 2, arc-shaped pilot pit blasting: A plurality of blast holes are arranged on the tunnel face close to the bottom of the pre-splitting zone, and explosives are filled in the blast holes and then detonated; wherein the blast holes are in an arc shape as a whole; Step 3: Reserve core soil for blasting: A plurality of blast holes are arranged on the blasting surface between the middle of the tunnel face and below the pre-splitting zone, and the blast holes are filled with explosives and then detonated; Step 4, blast down the stairs: A plurality of blast holes close to the bottom of the tunnel face are arranged below the middle of the tunnel face, and the explosives are detonated after being filled in the blast holes.

3. A method for reducing tunnel pipe support blasting damage according to claim 2, characterized in that: Guide slits are arranged on both sides of the blasthole in the pre-splitting zone, and the guide slits are arranged on both sides of the tunnel contour line.

4. A method for reducing tunnel pipe support blasting damage according to claim 2, characterized in that: The blastholes in step 2 include: cut holes, bottom plate holes, auxiliary holes and peripheral holes; The cutouts are symmetrically distributed on the center line of the tunnel face; The bottom plate eye is arranged around the bottom edge of the arc-shaped guide pit; The peripheral eyes are arranged at the edges of both sides of the arc-shaped guide pit; The auxiliary eyes are distributed above the bottom of the arc-shaped guide pit and are located around the groove eyes.

5. A method for reducing tunnel pipe-roof support blasting damage according to claim 2, characterized in that: The explosive is an emulsion explosive, and blasting is achieved by connecting a digital electronic mine with an external controller.

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