A directional pre-splitting blasting excavation device and method based on a composite drill rod

Abstract

The application provides a directional pre-splitting blasting excavation device and method based on a composite drill rod, which comprises a base, a sleeve rod and a center transmission drill rod. The base is arranged at the end of a drilling machine. One end of the sleeve rod is connected with the base through a pushing piece. The pushing piece pushes the sleeve rod to move back and forth relative to the base in the axial direction of the sleeve rod. The other end of the sleeve rod is provided with at least one wedge. The center transmission drill rod is arranged coaxially with the sleeve rod and penetrates the sleeve rod in the middle part. One end of the center transmission drill rod penetrates the base, and the other end is provided with a main drill bit. The main drill bit is arranged below the wedge. The drilling machine drives the center transmission drill rod to rotate and impact in the axial direction of the center transmission drill rod, and drives the sleeve rod to impact in the axial direction of the sleeve rod, so that the main drill bit drills a blast hole, the wedge drills a cutting groove area, and a directional cutting groove hole is formed. The application can accurately, timely and effectively control the pre-splitting blasting seam opening of high-stress rock mass, improves the seam forming effect, improves the pre-splitting seam vibration isolation effect, and is beneficial to the stable control of the blasting excavation of deep buried caverns.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of blasting excavation, and particularly relates to a directional pre-splitting blasting excavation device and method based on a composite drill rod. BACKGROUND

[0002] In the construction of deep rock mass such as hydropower and mine, the problems of pre-splitting blasting jointing of semi-infinite rock mass and high-stress rock mass, and rock breaking jointing control of ideal block size are usually faced. For pre-splitting blasting, the jointing effect directly affects the safety and stability of the formed surrounding rock, and the construction efficiency and safety of other structures under construction. Especially under high stress conditions, stress clamping and stress concentration can also cause large fluctuation and poor flatness of the formed surface in the pre-splitting blasting jointing forming. For such problems, especially for building structures with complex structure and high quality requirements for surrounding rock (such as rock anchor beam structure, high side wall structure, and intersection of cavern group of hydropower underground powerhouse), the traditional pre-splitting blasting construction, including the deep hole pre-splitting blasting jointing technology popularized in recent years, cannot effectively reduce the vibration influence and the damage degree of the surrounding rock while ensuring the pre-splitting jointing length and width by increasing the linear charge density or reducing the hole spacing; the pre-splitting joint is obviously affected by the stress environment, and is prone to not being penetrated or the crack expansion trend not being the formed surface. In terms of forming optimization, some new technologies have been accumulated, such as shaped charge blasting and slotting blasting. In these methods, the shaped charge blasting adjusts the explosive energy in the hole by adjusting the structure of the charge and increasing the energy concentration structure in the hole to promote the directional expansion of the crack; the energy concentration structure involved in this method increases the construction steps, and it is not easy to maintain the directional alignment after the shaped charge and the energy concentration structure are loaded into the hole, which can affect the construction efficiency and quality; the slotting blasting generally adopts the method of first drilling a circular hole and then performing directional slotting construction, which increases the construction steps and affects the construction efficiency. The existing related technologies involve the use of slotting knives and directional blocks to form slots, which are prone to misalignment due to rotation during drilling, and there is no efficient use of impact drilling and splitting slotting, the slotting shape forming effect is not high, the integrated slotting degree cannot be significantly improved, and the construction precision and efficiency are limited; the chain slotting forms narrow strip type fine cracks on both sides of the hole wall, which has large machine wear and low construction efficiency.

[0003] For the control of blasting rock block size, the traditional method mainly uses circular holes to control the rock breaking block size by adjusting the interval distance, charge amount, charge structure, and initiation section. The crack expansion around the hole induced by explosive initiation still shows randomness, and the crack expansion direction cannot be accurately controlled.

[0004] Therefore, the traditional method focuses on the macroscopic design adjustment (linear charge density, hole spacing, surrounding rock damage degree) of pre-splitting blasting forming and bench blasting block size control, and is restricted by the construction convenience of special-shaped holes in directional blasting, which seriously affects the construction efficiency and construction quality, and cannot improve the efficient mechanization of directional blasting excavation.

[0005] In view of the above problems, developing a blasting excavation technology that can ensure directional crack propagation and improve mechanized and efficient construction has important engineering significance for pre-splitting blasting forming and vibration isolation optimization, blasting excavation block size control, etc. SUMMARY

[0006] According to the deficiencies of the prior art, the purpose of the present application is to provide a directional pre-splitting blasting excavation device and method based on a composite drill rod, which can accurately, timely and effectively control the pre-splitting blasting aperture of high-stress rock mass, improve the crack forming effect, and improve the pre-crack vibration isolation effect, which is beneficial to the stable control of blasting excavation of deep buried caverns.

[0007] In order to solve the above technical problems, the technical scheme adopted by the present application is:

[0008] A directional pre-splitting blasting excavation device based on a composite drill rod, comprising:

[0009] a base provided at the end of a drilling machine;

[0010] a sleeve rod connected to the base at one end by a pushing member, and provided with at least one wedge at the other end, the pushing member pushing the sleeve rod to move back and forth relative to the base in the axial direction of the sleeve rod;

[0011] a center transmission drill rod, which is coaxially arranged with the sleeve rod and penetrates the sleeve rod at the middle, penetrates the base at one end, and is provided with a main drill bit at the other end, the main drill bit being arranged below the wedge;

[0012] Wherein, the center transmission drill rod is rotated by the drilling machine and impacted in the axial direction of the center transmission drill rod, and the sleeve rod is impacted in the axial direction of the sleeve rod, so that the main drill bit drills a blast hole and the wedge drills a slot area, and the blast hole and the slot area together form a directional slot hole.

[0013] Further, a tapered roller bearing is arranged between the top of the sleeve rod and the center transmission drill rod, and a rolling bearing is arranged between the bottom of the sleeve rod and the center transmission drill rod.

[0014] Further, the wedge includes a fixed body and at least one wedge body arranged on the fixed body, and the number and angle of the wedge bodies are set according to the required number and direction of rock cracking gaps.

[0015] Further, the fixed body is fixed on the sleeve rod, the splitting body is a quadrangular pyramid structure, including a quadrangular surface and four triangular surfaces, the quadrangular surface is arranged on the fixed body, one of the triangular surfaces is inclined to the axial direction of the sleeve rod by a certain angle, and a plurality of splitting angles distributed along the axial direction of the sleeve rod and arranged in a stepped manner are arranged on the triangular surface.

[0016] Further, adjacent splitting angles are kept at a distance of at least 2 times the length of the splitting angle in the axial direction of the drill rod, and a certain gap is formed between adjacent splitting angles.

[0017] Further, the drill machine is one of an internal combustion rock drill, a down-the-hole drill machine track type, a down-the-hole drill machine 100B or a multi-arm down-the-hole drill machine.

[0018] Further, the pushing member includes a cylinder and a piston rod, the cylinder is fixed on the base, and one end of the piston rod is arranged in the cylinder and the other end is fixed on the sleeve rod.

[0019] A directional pre-splitting blasting excavation method based on a composite drill rod uses any one of the directional pre-splitting blasting excavation devices based on the composite drill rod, and includes the following steps:

[0020] Drilling a directional slot hole by using the directional pre-splitting blasting device;

[0021] After the directional slot hole is formed, a mixed explosive truck is used to configure low-density gel mixed explosive on site, and the low-density gel mixed explosive is filled into the entire volume of the directional slot hole.

[0022] Initiating, so that the rock is directionally cracked, and the construction effect of mechanized and efficient directional pre-splitting or directional rock breaking is achieved.

[0023] Further, a certain volume of hollow plastic particles is mixed in the low-density gel mixed explosive.

[0024] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0025] The directional pre-splitting blasting excavation device and method based on the composite drill rod provided by the present application are characterized in that a center transmission drill rod is arranged in the sleeve rod to form a composite drill rod, the drill machine drives the center transmission drill rod to rotate and impact, a main drill bit drills a blast hole in the rock, one end of the sleeve rod is connected to the base through a pushing member arranged in the vertical direction, so that the sleeve rod can only reciprocatingly impact along the axial direction of the center transmission drill rod, and the splitting device drills a directional slot hole in an efficient and integrated manner during the reciprocating impact. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

[0027] Figure 1 Fig. 1 is a schematic diagram of the overall structure of the directional pre-splitting blasting excavation device based on the composite drill rod of the present application.

[0028] Figure 2 Fig. 2 is a schematic diagram of the structure of the sleeve rod and the center transmission drill rod connection of the present application.

[0029] Figure 3 Fig. 3 is a schematic diagram of the structure of the sleeve rod, the center transmission drill rod, and the bidirectional thrust bearing connection of the present application.

[0030] Fig. 4(a) is a schematic diagram of the first angle of the splitting body of the present application.

[0031] Fig. 4(b) is a schematic diagram of the second angle of the splitting body of the present application.

[0032] Fig. 4(c) is a schematic diagram of the third angle of the splitting body of the present application.

[0033] Figure 5 Fig. 5 is a top view of the directional pre-splitting blasting excavation device based on the composite drill rod of the present application.

[0034] Figure 6 Fig. 6 is a schematic diagram of the simultaneous operation of multiple directional pre-splitting blasting excavation devices of the present application.

[0035] Figure 7 Fig. 7 is a flowchart of the directional pre-splitting blasting excavation method based on the composite drill rod of the present application.

[0036] Wherein, 1, base; 2, sleeve rod; 21, splitter; 211, fixed body; 212, splitting body; 2121, splitting angle; 2122, first triangular surface; 2123, second triangular surface; 2124, third triangular surface; 2125, fourth triangular surface; 2126, quadrilateral surface; 22, second annular boss; 3, center transmission drill rod; 31, main drill bit; 32, first annular boss; 4, pushing piece; 5, tapered roller bearing; 6, rolling bearing. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application.

[0038] In the related art, under high stress conditions, stress clamping and stress concentration also affect the blasting seam forming, which can cause large fluctuation and poor flatness of the forming surface, if the traditional technology is used, mainly using circular blast hole, by adjusting the interval distance, charge weight, charge structure, initiation section, etc., the rock breaking size is controlled, the crack expansion around the blast hole induced by the initiation of the explosive still presents randomness, and the crack expansion direction cannot be accurately controlled.The present application provides a kind of directional pre-splitting blasting excavation device and method based on composite drill rod, directly changes the structure of the excavation device, forms a directional cutting groove, and places low-density explosives, which can ensure directional crack propagation and improve mechanized and efficient construction.

[0039] The present application provides a kind of directional pre-splitting blasting excavation device based on composite drill rod, as shown in Figure 1 The base 1 is clamped at the end of the drill.

[0040] The base 1 is clamped at the end of the drill.

[0041] One end of the sleeve rod 2 is connected to the base 1 by a pusher 4, and the other end is provided with at least one wedge 21, and the pusher 4 pushes the sleeve rod 2 to move relative to the base 1 in the axial direction of the sleeve rod.

[0042] The center transmission drill rod 3 is coaxially arranged with the sleeve rod 2, one end is provided with a main drill bit 31, and the other end is provided with a main drill bit 31.

[0043] Wherein, by driving the center transmission drill rod 3 to rotate and impact in the axial direction of the center transmission drill rod 3, and driving the sleeve rod 2 to impact in the axial direction of the sleeve rod 2, the main drill bit 31 drills the blast hole, and the wedge 21 drills the cutting groove area, and the blast hole and the cutting groove area are combined into a directional cutting groove.

[0044] The present application provides a kind of directional pre-splitting blasting excavation device based on composite drill rod, as shown in Figure 1 And Figure 2 The center transmission drill rod 3 is coaxially arranged with the sleeve rod 2, one end is provided with a main drill bit 31, and the other end is provided with a main drill bit 31.

[0045] In the present application, in order to realize the rotation and impact of the drill driven by the center transmission drill rod 3, the sleeve rod 2 reciprocating impact motion along the axial direction of the center transmission drill rod 3, the drill is one of internal combustion rock drill, down-the-hole drill crawler, down-the-hole drill 100B or multi-arm down-the-hole drill.

[0046] In the present application, as shown in Figure 1 The main drill bit 31 is in a cylindrical structure and is provided with a sharp end at the bottom, which facilitates the drilling of a circular hole profile.

[0047] Specifically, in the embodiment of the present application, as shown in Figure 1 The bottom of the main drill bit 31 is cut into two symmetrical half-elliptical sections, and the two half-elliptical sections form a sharp end at the joint.

[0048] In the present application, the sleeve rod 2 is in contact with the center drill rod through the rolling bearing, and the sleeve rod 2 is constrained in a ring shape by the pushing piece 4 and the base 1, so that the sleeve rod 2 only has a reciprocating impact movement along the axial direction of the center transmission drill rod 3.

[0049] Specifically, as shown in Figure 1 and Figure 3 A tapered roller bearing is provided between the top of the sleeve rod 2 and the center transmission drill rod 3, and a rolling bearing is provided between the bottom of the sleeve rod 2 and the center transmission drill rod 3, so that the sleeve rod 2 can reciprocate along the axial direction of the center transmission drill rod 3 through the tapered roller bearing, and the center transmission drill rod 3 can rotate in the sleeve rod 2 through the rolling bearing.

[0050] Specifically, two tapered roller bearings 5 are sleeved on the center transmission drill rod 3 at a certain distance, one of which is positioned by the first annular boss 32 on the center transmission drill rod 3, and the other is positioned by the nut 7 threaded with the center transmission drill rod 3, the sleeve rod 2 is sleeved outside the two tapered roller bearings 5, the second annular boss 22 is provided on the sleeve rod 2, and the second annular boss 22 is clamped between the two tapered roller bearings 5.

[0051] The sleeve rod 2 is provided outside the rolling bearing, and the center transmission drill rod 3 is provided inside the rolling bearing.

[0052] In the present application, as shown in Figure 1 The pushing piece 4 includes a cylinder and a piston rod, the cylinder is fixed on the base 1, one end of the piston rod is arranged in the cylinder, and the other end is fixed on the sleeve rod 2, so that the sleeve rod 2 only has a reciprocating impact movement along the axial direction of the center transmission drill rod 3.

[0053] In the present application, as shown in FIG. 4(a)-4(b), the wedge 21 comprises a fixed body 211 and at least one wedge body 212 arranged on the fixed body 211, and the number and angle of the wedge body 212 are set according to the required number and direction of rock cracking fissures. When the directional pre-splitting blasting excavation device has the wedge 21 in different directions, the rock is easy to crack in these directions, which makes the cracking direction and length of the rock in two dimensions controllable, and when multiple directional cutting holes are adjacent and cut each other, the size of the rock cut by the inter-hole cracking can be controlled, and the control of the rock breaking size is achieved.

[0054] For example, when the rock needs to form horizontal transverse or longitudinal cracks, two wedge bodies 212 are arranged symmetrically and parallel to the fixed body 211, and when the rock needs to form horizontal transverse and longitudinal cracks at the same time, four wedge bodies 212 are arranged symmetrically with respect to the fixed body 211.

[0055] Specifically, the fixed body 211 is fixed on the sleeve rod 2, the wedge body 212 has a four-pyramid structure comprising a quadrilateral face and four triangular faces, the quadrilateral face is arranged on the fixed body 211, one of the triangular faces is inclined at a certain angle with respect to the axial direction of the sleeve rod 2, and a plurality of wedge angles arranged in the axial direction of the sleeve rod 2 and in a stepped manner are arranged on the triangular face, the cross section of the wedge angle is triangular, and the plurality of wedge angles arranged in a stepped manner can perform new wedge one by one, repeated impact, and layer-by-layer stripping to form a triangular cutting groove area with a depth direction divided into multiple layers.

[0056] As shown in FIG. 4(b), the spacing between adjacent wedge angles is The spacing between the top of each wedge angle and the previous wedge angle is at least 2 times the length of the wedge angle, and there is a certain space between the top of each wedge angle and the previous wedge angle, which provides space for the discharge of wedge rock debris.

[0057] In the actual application of the present application, the wedge is integrally manufactured by directly manufacturing the wedge at different angles of the sleeve rod during the manufacturing of the whole wedge, so that the conical cutting groove area is formed at different angles during the reciprocating impact of the drill rod.

[0058] In the present application, as shown in Figure 5 and Figure 6 By setting multiple directional pre-splitting blasting excavation devices for excavation, the conventional round hole pre-splitting blasting needs to ensure that the holes are cracked, and the hole spacing is generally set to 8-12 times the diameter of the pre-splitting hole. Since the present application is provided with the wedge 21, the directional cutting hole is easier to crack in the cutting direction, and the crack length is also longer under the same amount of explosive, so the hole spacing of the cutting pre-splitting hole can be relaxed. Therefore, the number of blast holes is reduced for the same length of pre-splitting blasting.

[0059] ​When the composite drill rod has wedge splitters in different directions, the rock is easy to crack in these directions, which makes the cracking direction and length of the rock in two size dimensions controllable, and when multiple directional cutting slots are adjacent and cut each other, the size of the rock cut by the inter-hole cracking can be controlled, and the control of the rock breaking size is achieved.

[0060] The application also provides a directional pre-splitting blasting excavation method based on a composite drill rod, as shown in the accompanying drawings. Figure 7 As shown in the accompanying drawings, the directional pre-splitting blasting excavation device based on the composite drill rod comprises the following steps:

[0061] The directional cutting slot drilling is performed by the directional pre-splitting blasting excavation device, so as to ensure that the cutting direction is the forming requirement direction or the breaking direction.

[0062] After the directional cutting slot is formed, a mixed explosive truck is used to configure low-density gelatin mixed explosive on site, and the low-density gelatin mixed explosive is filled into the entire volume of the directional cutting slot.

[0063] The low-density gelatin mixed explosive is detonated, so that the rock is directionally cracked, and the construction effect of the mechanized and efficient directional pre-splitting or directional rock breaking is achieved.

[0064] The low-density gelatin mixed explosive is mixed with a certain volume of hollow plastic particles.

[0065] The directional cutting slot formed based on the application reduces the in-hole load required for rock cracking, and the emulsion explosive with a lower density can be used in the directional cutting slot, so that the vibration induced by the explosive is also reduced.

[0066] In an embodiment of the application, a directional pre-splitting blasting excavation device based on a composite drill rod is provided, and specifically comprises:

[0067] The outer part of the directional pre-splitting blasting excavation device is designed as a fixed rigid sleeve rod 2 with an outer diameter of 50 mm, an inner diameter of 40 mm, and a length of 4 m, and the inner part is designed as a center transmission drill rod 3 with a diameter of 24 mm.

[0068] Two parallel multi-layer conical wedge splitters 21 are fixedly arranged at 0° and 180° positions of the front end (100 mm away from the front end) of the fixed rigid sleeve rod 2, respectively, with the contact points of the wedge splitters 21 with the circular blast hole being at 45°, 135°, 225°, and 315°, i.e., the formed conical groove is 60°, and the farthest points of the two conical wedge splitters 21 are located at ± mm, respectively.

[0069] The fixed sleeve rod 2 is connected with the center transmission drill rod 3 through the front end rolling bearing and the rear end tapered roller bearing; the rolling bearing mainly ensures that the center drill rod is always on the axial center line while rotating; and the tapered roller bearing mainly aims to realize the reciprocating impact of the outer sleeve rod 2 driven by the axial reciprocating impact of the center drill rod while rotating in the ring direction.

[0070] Step 1: The composite drill rod is used to drill the directional slot hole along the intended forming surface; when the drilling depth reaches, the front end 200 mm is the hole inner super depth, the hole spacing is 1.0 m, and the adjacent slot directions are parallel and aligned to ensure that the slot direction is the required direction of forming;

[0071] Step 2: After the slot hole is formed, the mixed explosive truck is used to configure the low-density mixed explosive on site, and the low-density mixed explosive is quickly filled into the entire volume of the directional slot hole; the on-site mixing of the low-density mixed explosive is mainly carried out through the mixed explosive truck, and 30% of hollow plastic particles are added in the gelatinous mixed explosive to reduce the density of the gelatinous emulsion explosive, so as to reduce the influence range of the crushing zone in the near zone of the blast hole and reduce the induced surrounding rock vibration;

[0072] Step 3: Initiation, so that the rock is directionally pre-cracked into a joint, and the mechanical and efficient directional pre-cracking construction effect is achieved, and the pre-crack surface is well formed.

[0073] In summary, the present application aims to drill the blast hole by the composite drill rod, so that the slot hole is formed at one time; the slot hole blasting joint direction can be controlled, the blast energy tends to propagate in the slot direction, and the slot direction crack propagation is easier. Therefore, even in high stress and complex stress field, the crack will tend to crack, expand and extend in the slot hole direction, which can improve the problem of large crack forming undulation affected by high stress environment.

[0074] And the load required for crack expansion at the slot hole of the present application is significantly lower than that of the conventional round hole, and the vibration induced by the load is also significantly reduced; the cracks induced by the present application mainly expand in the slot direction, and there are fewer cracks in the non-slot direction (reserved surrounding rock direction), so the damage to the reserved surrounding rock can be significantly reduced.

[0075] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A directional pre-splitting blasting excavation device based on a composite drill rod, characterized in that, include: The base is located at the end of the drilling rig; A sleeve rod, one end of which is connected to the base via a pusher, and the other end of which is provided with at least one splitter. The pusher pushes the sleeve rod to move back and forth relative to the base in the axial direction of the sleeve rod. A central drive drill rod has a sleeve rod inserted through its middle and arranged coaxially with the sleeve rod. One end of the sleeve rod passes through the base, and the other end is equipped with a main drill bit, which is located below the splitter. In this process, the drilling rig drives the central drive drill rod to rotate and impacts it in the axial direction, and drives the sleeve rod to impact in the axial direction, so that the main drill bit drills blast holes and the splitter drills the cutting area. The blast holes and the cutting area together form a directional cutting hole. A tapered roller bearing is provided between the top of the sleeve rod and the central drive drill rod, and a rolling bearing is provided between the bottom of the sleeve rod and the central drive drill rod; The rock splitter includes a fixed body and at least one splitting body disposed on the fixed body. The number and angle of the splitting body are set according to the required number and direction of rock fissures. The fixing body is fixed to the sleeve rod. The splitting body is a four-sided pyramid structure, including a quadrilateral face and four triangular faces. The quadrilateral face is provided on the fixing body. One of the triangular faces is inclined at a certain angle relative to the axial direction of the sleeve rod. The triangular face is provided with multiple splitting angles distributed along the axial direction of the sleeve rod in a stepped shape. The cross section of the splitting angle is triangular. The multiple splitting angles in a stepped shape can split new layers one by one, repeatedly impact, peel off layer by layer, and form a triangular groove area. The spacing h2 between adjacent splitting angles shall be at least twice the length of the splitting angle h1 along the axial direction of the drill pipe, and there shall be a certain gap between adjacent splitting angles. The pushing component includes a cylinder and a piston rod. The cylinder is fixed on the base, and one end of the piston rod is located inside the cylinder, while the other end is fixed on the sleeve rod.

2. The directional pre-splitting blasting excavation device based on composite drill rod according to claim 1, characterized in that: The drilling rig is one of the following: internal combustion rock drill, crawler down-the-hole drill, down-the-hole drill 100B, or multi-arm down-the-hole drill.

3. A method for directional pre-splitting blasting excavation based on composite drill rods, using the directional pre-splitting blasting excavation device based on composite drill rods as described in any one of claims 1-2, characterized in that, Includes the following steps: Drilling of directional slots using a directional pre-splitting blasting excavation device; After the directional slotted holes are formed, a mixed explosives truck is used to prepare low-density gel-mixed explosives on site and fill them into the entire volume of the directional slotted holes. The detonation causes the rock to fracture in a specific direction, achieving a mechanized and efficient directional pre-splitting or directional rock breaking construction effect.

4. The directional pre-splitting blasting excavation method based on composite drill rod according to claim 3, characterized in that: The low-density gel-mixed explosive contains a certain volume of hollow plastic particles.

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