A semi-enclosed active cracking underground engineering blast protection structure and method

Abstract

The application discloses a kind of semi-enclosed active fracturing underground engineering blast protection structure and method, belong to underground engineering blast protection technical field, including a plurality of fracturing device, the horizontal projection of fracturing device in first fracturing zone is arranged in multiple rows and adjacent two rows of fracturing device are staggered distribution, the fracturing disc on same row fracturing device is in parallel state, the fracturing disc on adjacent two rows of fracturing device is in orthogonal state;The fracturing disc of type I fracturing device is arranged in first fracturing zone, the fracturing disc of type II fracturing device is arranged in first fracturing zone and top fracturing zone, the fracturing disc of type III fracturing device is arranged in first fracturing zone, top fracturing zone and side edge fracturing zone.The application reduces the influence of explosion impact on underground engineering by active defense mode, and the fracturing disc arranged obliquely in second fracturing zone forms semi-enclosed protection fracturing layer closely and evenly around underground engineering after explosion, to ensure the accuracy of underground engineering protection.

Description

Technical Field

[0001] The present invention belongs to the technical field of underground engineering anti-explosion protection, and in particular relates to a semi-enclosed active-fracture underground engineering anti-explosion protection structure and method. Background Art

[0002] Currently, common blast protection methods primarily focus on optimizing protective design. For example, geometric optimization is used to increase the depth of the cavern to leverage the natural attenuation of shock waves by the ground; arched or circular cross-sections (such as horseshoe-shaped tunnels) are used to avoid stress concentration at right angles and evenly distribute blast loads; and explosion-proof partitions are used to divide the cavern into independent units to prevent cascading damage (such as in underground nuclear power plants). Optimizing the blast-resistant structural layer can improve the blast resistance of underground projects by adopting composite linings and composite sandwich structures. These methods passively withstand the impact of stress waves that have already propagated to the underground structure. However, these measures are inadequate in terms of protection coverage and are ineffective in resisting blasts. Summary of the Invention

[0003] Most of the existing traditional underground engineering explosion-proof protection methods are explosion-proof protection measures taken when passively bearing the impact of stress waves that have propagated to the underground structure. The purpose of the present invention is to propose a semi-enclosed active fracture underground engineering explosion-proof protection structure and method that actively creates a fracture surface in the surrounding rock and effectively blocks the propagation of stress waves.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is:

[0005] A semi-enclosed active fracturing underground engineering explosion-proof protection structure, wherein the area of ​​the upper surrounding rock near the ground is called the first fracturing zone, the surrounding rock area around the underground engineering is called the second fracturing zone, the surrounding rock area located at the top of the underground engineering in the second fracturing zone is called the top fracturing zone, and the surrounding rock areas located on both sides of the underground engineering in the second fracturing zone are called the side fracturing zones. The underground engineering explosion-proof protection structure includes a plurality of fracturers arranged in the first fracturing zone and the second fracturing zone. The projections of the fracturers located in the first fracturing zone on the horizontal plane are arranged in multiple rows, and the adjacent rows of fracturers are staggered. The fracturing disks on the same row of fracturers are parallel, and the adjacent rows of fracturers are arranged in parallel. The rupture disks on the devices are orthogonal; the rupture disks on the same row include type I rupture disks located at the edge, type II rupture disks located in the middle, and type III rupture disks located between the type I and type II rupture disks. The rupture disks of the type I rupture disks are located in the first rupture zone, the rupture disks of the type II rupture disks are located in the first rupture zone and the top rupture zone, and the rupture disks of the type III rupture disks are located in the first rupture zone, the top rupture zone, and the side rupture zones. The rupture disks include a rupture disk filled with explosives and a conduit extending in a vertical direction. After the conduit is connected to the center of the rupture disk, the inclination angle of the rupture disk on the vertical plane projection is β.

[0006] As an improvement to the above technical solution, a first detonating cord extending in a vertical direction is provided in the chamber of the catheter, and the chamber inside the rupture disk includes an annular explosive chamber arranged on the periphery of the rupture disk and used to bury explosives, and an annular detonator chamber arranged between the explosive chamber and the catheter and used to lay detonators, and the explosive chamber and the detonator chamber are in a connected state; a second annular detonating cord is provided in the explosive chamber, and the detonating joint of the second detonating cord and the detonating joint of the detonator are both connected to the first detonating cord.

[0007] As an improvement to the above technical solution, the middle portion of the outer wall of the rupture disk is recessed toward the direction close to the catheter so that the outer wall of the rupture disk is arranged in a "V" shape.

[0008] As an improvement to the above technical solution, the inclination angles of the fracture disks on the Type II and Type III fracture devices in the top fracture zone are both 90°, the inclination angles of the fracture disks on the same Type III fracture device in the side fracture zone are the same, and the inclination angle β of the fracture disks on one side of the underground project in the same row is a small angle of 0-5°, and the inclination angle of the fracture disks on the other side of the underground project is (180°-β).

[0009] As an improvement to the above technical solution, the inclination angles of the fracturing disks on the Type II and Type III fracturing devices in the top fracturing zone should satisfy the following requirements: when the top contour surface of the underground project deviates upward to pass through the center of the fracturing disk, the corresponding fracturing disk is tangent to the top contour surface after the deflection; the inclination angles of the fracturing disks on the same Type III fracturing device in the side fracturing zone are the same, and the inclination angle β of the fracturing disks on one side of the underground project in the same row is a small angle of 0-5°, and the inclination angle of the fracturing disks on the other side of the underground project is (180°-β).

[0010] As an improvement to the above technical solution, the lowest fracturing disk on the Type II fracturing device in the top fracturing zone is required to be at least 1 / 2 of the underground project cavern span size away from the top of the underground project, and the fracturing disk on the Type III fracturing device adjacent to the Type II fracturing device in the side fracturing zone is required to be at least 1 / 2 of the underground project cavern span size away from the side of the underground project.

[0011] In order to achieve the above-mentioned purpose, the present invention also adopts the following technical solutions:

[0012] A semi-enclosed active fracturing underground engineering explosion protection method is based on uniformly arranging the aforementioned semi-enclosed active fracturing underground engineering explosion protection structure in the protection area. The specific process is as follows:

[0013] S1: Calculate the installation hole position and depth of the fracturing device and the size of the fracturing disk on the fracturing device according to the shape of the building structure to be protected;

[0014] S2: After determining the depth of the mounting holes, drill the holes. The resulting horizontal projections of the mounting holes are arranged in multiple rows, with adjacent rows staggered to form a plum blossom arrangement. In the same row, the mounting holes at the edge should extend to the first cracking zone, the mounting holes in the middle should extend to the top cracking zone, and the mounting holes between the edge and the middle should extend to the side cracking zone.

[0015] S3: Install Type I crackers in the mounting holes at the edge of the same row, install Type II crackers in the mounting holes in the middle, and install Type III crackers in the remaining mounting holes. The multiple crack disks of the same cracker are vertically segmented. First, the multiple layers of crack disks on each Type I, Type II, and Type III cracker in the first cracking zone are divided into at least two sections. The first vertically uppermost cracking disk is detonated to form a permanent cracking zone in the upper layer, and the remaining multiple cracking disks are detonated to form an immediate cracking zone in the lower layer. Second, all the cracking disks of the Type II cracker in the second cracking zone and all the cracking disks of the Type III cracker in the second cracking zone are divided into one section.

[0016] S4: Deploying vibration velocity sensors on the inner wall of the mounting holes corresponding to each rupture disk in the first rupture zone and on the inner wall of the mounting holes corresponding to the uppermost rupture disk in the second rupture zone, and setting thresholds for triggering rupture disk explosion for the vibration velocity sensors;

[0017] S5: explosively fracturing the first segment of the fracturing disk on the fracturing device in the first fracturing zone to obtain a permanent fracturing zone;

[0018] S6: When the explosion impact intensity sensed by the corresponding vibration velocity sensor reaches the set explosion threshold, the remaining segments of the fracture disks distributed along the vertical direction in the first fracture zone are sequentially subjected to segmented explosive fracture to form a deeper instant fracture zone. After all the fracture disks in the first fracture zone are exploded, the fracture disks in the second fracture zone are subjected to explosive fracture.

[0019] As an improvement to the above technical solution, in step S3, after the fracturing devices are installed in the installation holes, the centers of the fracturing disks at the same level on the fracturing devices are on the same plane.

[0020] As an improvement to the above technical solution, in step S4, the vibration velocity sensor in the first fracturing zone is arranged in the immediate fracturing zone and on the inner wall of the mounting hole corresponding to the uppermost fracturing disk in each fracturing disk, and the maximum value of the spacing and row spacing of the vibration velocity sensors is less than or equal to the minimum size of the protected underground project on the plane.

[0021] As an improvement of the above technical solution, in step S5, after explosive fracturing of the first segment of the fracturing disk on the fracturing device in the first fracturing zone, grouting is performed on the fracture surface through the mounting hole to obtain a permanent fracturing zone.

[0022] The semi-enclosed active fracturing underground engineering explosion-proof protection structure and method of the present invention can achieve the following beneficial effects:

[0023] (1) The fracturing device used in the underground engineering protection structure only includes a conduit extending in the vertical direction and a number of fracturing disks connected to the conduit and parallel to the inclined direction. It has a simple structure and is easy to manufacture. During protection, several different fracturing devices are buried in several installation holes in the underground engineering protection area and then multiple segmented fracturing explosions are carried out. The impact of the explosion shock on the underground engineering is reduced by active defense. The explosion-proof range is large, the effect is good, the construction process is simple, and the construction time is shortened.

[0024] (2) The protection of underground engineering fracturing devices is divided into two forms: the first fracturing zone and the second fracturing zone. The first fracturing zone forms a uniform permanent fracturing protection layer and an immediate fracturing layer after fracturing by the fracturing disk, realizing segmented protection, while the fracturing disk in the second fracturing zone can fract the surrounding rock around the underground engineering according to the specific shape of the underground engineering, forming a close and uniform semi-enclosed protective fracturing layer around the underground engineering, ensuring the accuracy of the protection of the underground engineering. The fracturing disk can form a fracture surface that can fit the contour of the underground engineering by tilting the angle, so as to achieve more complete protection of the underground engineering while minimizing the damage to the surrounding rock of the underground engineering.

[0025] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 FIG. 1 is a schematic diagram of a single-layer structure rupture device including a rupture disk in an inclined state according to the present invention.

[0027] Figure 2 This invention Figure 1 The cross-sectional view of the rupture disk in the rupture device shown is in a horizontal position.

[0028] Figure 3 It is an axonometric schematic diagram of the Type I cracker of the present invention.

[0029] Figure 4 It is an axonometric schematic diagram of a first embodiment of a semi-enclosed active fracturing underground engineering explosion-proof protection structure of the present invention.

[0030] Figure 5This invention Figure 4 Top view of .

[0031] Figure 6 This invention Figure 4 Schematic diagram of the vertical cross section of the odd-numbered rows.

[0032] Figure 7 This invention Figure 4 Schematic diagram of the cross section of the even-numbered rows in the vertical direction.

[0033] Figure 8 This invention Figure 4 Axonometric diagram of a Type II cracker.

[0034] Figure 9 This invention Figure 4 Axonometric diagram of one embodiment of a Type III cracker.

[0035] Figure 10 This invention Figure 4 Axonometric diagram of another embodiment of the Type III cracker.

[0036] Figure 11 It is an axonometric schematic diagram of a second embodiment of a semi-enclosed active fracturing underground engineering explosion-proof protection structure of the present invention.

[0037] Figure 12 This invention Figure 11 Schematic diagram of the vertical cross section of the odd-numbered rows.

[0038] Figure 13 This invention Figure 11 Schematic diagram of the cross section of the even-numbered rows on the vertical plane.

[0039] Figure 14 This invention Figure 11 Schematic diagram of the type II cracker.

[0040] Figure 15 This invention Figure 11 Schematic diagram of one embodiment of a Type III cracker.

[0041] Figure 16 This invention Figure 11 Schematic diagram of another embodiment of the Type III cracker.

[0042] Among them, 1. Type I cracker; 11. Type II cracker; 12. Type III cracker; 13. First cracking zone; 14. Top cracking zone; 15. Side cracking zone; 2. Cracking disk; 3. Conduit; 4. Explosive chamber; 5. Detonator chamber; 601. First detonating cord; 602. Second detonating cord; 7. Mounting hole; 8. Fracture surface; 9. Underground engineering; 91. Top contour surface; 91', top contour surface after offset; 10. Vibration velocity sensor. DETAILED DESCRIPTION

[0043] The features and exemplary embodiments of various aspects of the present invention are described in detail below. In the detailed description that follows, many specific details are set forth in order to provide a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be implemented without some of these specific details. The following description of the embodiments is intended only to provide a better understanding of the present invention by illustrating examples of the present invention. In the drawings and the following description, at least some of the well-known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention; and, for clarity, the sizes of some structures may be exaggerated. The features, structures, or characteristics described below may be combined in any suitable manner in one or more embodiments. In addition, the terms "first or I", "second or II", "third or III", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

[0044] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of the present invention. In the description of the present invention, it should also be noted that, unless otherwise clearly stipulated and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In the present invention, the direction in which the underground project extends to the ground is the vertical direction, and the direction perpendicular to the vertical direction is the horizontal direction.

[0045] A semi-enclosed active fracturing underground engineering explosion-proof protection structure includes a plurality of fracturing devices evenly arranged in the protection area, the fracturing device includes a conduit 3 extending in the vertical direction and a plurality of fracturing disks 2 arranged in an inclined state, the conduit 3 is connected to the center position of the fracturing disk 2, and the angle between the fracturing disk and the conduit in the vertical projection is β (such as Figure 1 As shown, this angle is called the inclination angle of the fracturing disk). The guide tube 3 located at the center enables the fracturing disk 2 to evenly explosively fracture the surrounding rock after detonation, thereby achieving a better fracturing effect. The projections of the multiple fracturing devices on the horizontal plane are arranged in multiple rows, and the adjacent rows of fracturing devices are staggered, as shown in FIG. Figure 5 See also Figure 1 、 Figure 2 , taking a fracture disk connected to a conduit in an inclined state as an example to describe the structure of the fracture disk, the chamber inside the fracture disk 2 includes an explosive chamber 4 and a detonator chamber 5. The explosive chamber 4 is an annular structure chamber arranged on the outer periphery of the disc-shaped fracture disk 2. The annular structure of the explosive chamber can realize the uniform arrangement of the explosives inside the fracture device, and the explosives located at the outer edge of the fracture disk are more conducive to the fracture of the surrounding rock during the explosion, which is safer and more convenient in the arrangement and use of the fracture device 1; the detonator chamber 5 is an annular structure chamber arranged between the explosive chamber 4 and the conduit 3, and the detonator chamber and the explosive chamber are connected to each other; a vertically extending chamber is provided in the chamber of the conduit 3. A first detonating cord 601 extends toward the blast chamber 4, a second detonating cord 602 is buried in a ring shape in the blast chamber 4, and detonators are arranged in the detonator chamber 5. The detonating joints of the second detonating cord 602 and the detonating joints of the detonators are both connected to the first detonating cord 601. With the help of the double insurance design of the second detonating cord and the detonator, the explosives in the blast chamber are guaranteed to be detonated and duds are avoided. At the same time, the ring-shaped second detonating cord can simultaneously detonate the explosives in the blast chamber 4, thereby realizing the fracturing process of the cracker. At the same time, the first detonating cord 601 extending from the guide tube 3 realizes remote control of the explosion process of the cracker 1, which is conducive to the synchronous detonation of multiple crackers. In order to further optimize the structure of the fracturing disk 2, the outer wall surface (i.e., the outer arc surface extending in the circumferential direction) of the fracturing disk 2 is recessed in the middle portion toward the guide tube 3 so that the outer wall surface of the fracturing disk 2 is arranged in a "V" shape. This structure enables the explosive to more concentratedly impact the surrounding rock at the "V"-shaped notch during the explosion, thereby increasing the strength of the broken surrounding rock. The explosive can effectively expand the fracturing range and save the use of explosives. Please also refer to Figure 2 The thickness of the explosive chamber 4 in the vertical direction is greater than the thickness of the detonator chamber 5 in the vertical direction, so that the central area of ​​the fracturing disk 2 is pit-shaped compared to the outer edge area, which can further expand the fracturing range.

[0046] Reference Figure 3 、 Figure 8 、 Figure 9 、 Figure 14 、 Figure 15The fracturers on the same row include a type I fracturer 1 located at the edge, a type II fracturer 11 located in the middle, and a type III fracturer 12 located between the type I and type II fracturers. A corresponding number of fracture disks 2 are arranged in the vertical direction on the guide tubes of the type I fracturer 1, the type II fracturer 11, and the type III fracturer. Among them, the type I fracturer is vertically penetrated in the upper surrounding rock area near the ground, the type II fracturer is vertically penetrated in the upper surrounding rock area near the ground and the surrounding rock area at the top of the underground project, and the type III fracturer is vertically penetrated in the upper surrounding rock area near the ground and the surrounding rock area on the side of the underground project. The inclination angles of several fracturing disks on the same Type I fracturing device are the same, the inclination angles of the fracturing disks in the upper surrounding rock area near the ground on the same Type II fracturing device are the same, and the inclination angles of the fracturing disks in the upper surrounding rock area near the ground on the same Type III fracturing device are different. The fracture surfaces formed by detonating the aforementioned fracturing disks can form basic fracturing protection for underground projects. In locations deep underground and close to underground projects, another part of the fracturing disks on the Type II fracturing device and another part of the fracturing disks on the Type III fracturing device can fracture the surrounding rock according to the explosion intensity and the specific conditions of the underground project, forming precise fracturing protection. When performing precise fracturing protection, in order to ensure uniform and stable protection of the underground project, the fracturing disks can form a fracture surface that can fit the contour of the underground project by changing the inclination angle β. In this way, precise protection of the underground project can be achieved while minimizing damage to the surrounding rock of the underground project.

[0047] Reference Figure 4 、 Figure 11 In this embodiment, the upper surrounding rock area near the ground is referred to as the first fracturing zone 13, the surrounding rock area around the underground project is referred to as the second fracturing zone, the surrounding rock area at the top of the underground project in the second fracturing zone is referred to as the top fracturing zone 14, and the surrounding rock areas on both sides of the underground project in the second fracturing zone are referred to as the side fracturing zones 15. Figure 8 、 Figure 9 、 Figure 12 、 Figure 13 The multiple levels of rupture disks on several rupture devices are respectively arranged in the first rupture zone 13 and the second rupture zone. Specifically, the rupture disks of the Type I rupture device 1 are all arranged in the first rupture zone 13, the rupture disks of the Type II rupture device 11 are respectively arranged in the first rupture zone 13 and the top rupture zone 14, and the rupture disks of the Type III rupture device 12 are respectively arranged in the first rupture zone 13, the top rupture zone 14, and the side rupture zone 15. Furthermore, with respect to the first rupture zone, the horizontal projections of the Type I rupture device 1, the Type II rupture device 11, and the Type III rupture device 12 follow the plum blossom arrangement principle. Specifically, the projections of the rupture devices on the horizontal plane are arranged in multiple rows, and the rupture devices in adjacent rows are staggered. The centers of the rupture disks of the same level on different rupture devices are located on the same horizontal plane (e.g., Figure 8 、 Figure 9 、 Figure 12 、 Figure 13 As shown in the figure, the inclination angle of the rupture disks on the type I, type II, and type III rupture devices in the same row is 45°, and the inclination angle of the rupture disks on the type I, type II, and type III rupture devices in adjacent rows is 135°, so that the rupture disks in the two adjacent rows are orthogonal. Furthermore, with respect to the second fracturing zone, the inclination angles of the fracturing disks on the type II and type III fracturing devices in the top fracturing zone are both 90°, the inclination angles of the fracturing disks on the same type III fracturing device in the side fracturing zone are the same, and the inclination angle of the fracturing disks on the same row located on one side of the underground project is β (should be a small angle, for example, β = 0-5°), and the inclination angle of the fracturing disks on the other side of the underground project is (180°-β), or the inclination angles of the fracturing disks on the type II and type III fracturing devices in the top fracturing zone should satisfy the following conditions: when the top contour surface 91 of the underground project deviates upward to pass through the center of the fracturing disk, the corresponding fracturing disk is tangent to the deviated top contour surface 91', and the inclination angles of the fracturing disks on the same type III fracturing device in the side fracturing zone are the same, and the inclination angle of the fracturing disks on the same row located on one side of the underground project is β (should be a small angle, for example, β = 0-5°), and the inclination angle of the fracturing disks on the other side of the underground project is (180°-β).

[0048] Reference Figures 4-10As a first embodiment of the present invention, when defending an underground project 9, the fracturing discs of the Type I fracturing device 1 are all placed within the first fracturing zone 13. The number of fracturing discs in the first fracturing zone for each Type II fracturing device 11 and each Type III fracturing device 12 is the same as the number of fracturing discs in the first fracturing zone 13 (six each). Furthermore, the inclination angle β of the fracturing discs in one row of fracturing devices in the first fracturing zone is 45°, while the inclination angles of the fracturing discs in adjacent rows are 135°. Before installing the fracturing discs in the first fracturing zone 13, the drilling depth of the installation holes can be set based on the potential impact depth of the underground project and, in principle, should be greater than the impact depth. The principle for hole placement and placement of the fracturing discs is to ensure that the horizontal projection of the rock mass fracturing range effectively covers at least 80% of the site surface. The fracturing disks on the Type II and Type III fracturing devices located in the top fracturing zone are all arranged parallel to the horizontal plane (i.e., the inclination angle β of the fracturing disks is 90°), and the number of fracturing disks is determined according to the defense requirements. The centers of the fracturing disks of the same level on different Type II and Type III fracturing devices should be located in the same plane, and several layers of fracturing disks are in a parallel state. In this embodiment, the fracturing disk examples of the Type II and Type III fracturing devices 11 and 12 in the top fracturing zone 14 are both three layers. In addition, the lowest fracturing disk on the Type II fracturing device 11 in the top fracturing zone 14 is required to be at least 1 / 2 of the span of the underground engineering cavern from the top of the underground project to ensure the integrity of the rock mass surrounding the underground engineering cavern. At the same time, the arrangement of the above-mentioned fracturing disks should ensure that the horizontal projection of the rock mass fracturing range can effectively cover more than 80% of the top area of ​​the underground project. The fracturing disks on the Type III fracturing device 12 located in the side fracturing zone 15 are arranged on both sides of the underground project. The inclination angle of the fracturing disks on the left side of the underground project on the same row of Type III fracturing devices is 5°, and the inclination angle of the fracturing disks on the right side of the underground project is 175°. In addition, the centers of the fracturing disks on the same level of the Type III fracturing devices in the same row should be located on the same horizontal plane. In this embodiment, the example of the fracturing disks located in the side fracturing zone on the Type III fracturing device is three layers. In addition, the fracturing disks on the Type III fracturing device adjacent to the Type II fracturing device in the side fracturing zone (i.e., the Type III fracturing device closest to the underground project in the same row) are required to be at least 1 / 2 of the span of the underground project cavern from the side of the underground project to ensure the integrity of the rock mass around the cavern. It should ensure that the lateral projection of the rock mass fracturing range can effectively cover more than 80% of the side of the underground project. This embodiment enables the fracturing disks on the same row of type II and type III fracturing devices in the second fracturing zone to be distributed in a gate-shaped manner on the vertical cross section, forming a gate-shaped fracturing zone on the vertical cross section, which provides better protection for underground projects.

[0049] Reference Figures 11-16As a second embodiment of the present invention, when defending an underground project, this embodiment differs from the first embodiment described above only in that, when the arched top profile surface 91 of the underground project is deflected upward to pass through the center of the rupture disks within the top rupture zone, the corresponding rupture disks on the Type II and Type III rupture devices within the top rupture zone become tangent to the deflected top profile surface 91'. As a result, the two layers of rupture disks (five rupture disks in the upper layer and three rupture disks in the lower layer) within the top rupture zone in odd-numbered rows are both arched in vertical cross-section. The two layers of rupture disks (four rupture disks in each layer) within the top rupture zone in even-numbered rows are also arched in vertical cross-section. By detonating some of the rupture disks within the top rupture zone and others within the side rupture zones, an arched rupture zone is formed that matches the vertical cross-section of the underground project, providing better protection for such arched underground projects.

[0050] Based on the aforementioned semi-enclosed active fracturing underground engineering explosion protection structure, the present invention also proposes a semi-enclosed active fracturing underground engineering explosion protection method, which divides the multiple fracturing disks on the same fracturing device into segments along the vertical direction and then performs segmented explosive fracturing. The specific process is as follows:

[0051] First, the size of the fracturing disk of the fracturing device and the positions of the plurality of mounting holes 7 are calculated based on the shape of the building structure to be protected. The specific process is as follows: the protection area of ​​the underground project to be protected is divided into a first fracturing zone 13 and a second fracturing zone consisting of a top fracturing zone 14 and a side fracturing zone 15 according to the shape of the underground project to be protected; the drilling size, the size of the fracturing disk, and the charge are determined through blasting fracturing tests; the distance between adjacent mounting holes is determined by the coverage of the fracture surface of the rock mass after the fracturing disk is blasted; and finally, the optimal drilling plan and fracturing disk size are determined under the premise of meeting technical requirements; then, drilling is performed according to the positions and depths of the mounting holes calculated above. The drilling depth must be precise, and the horizontal projections of the resulting plurality of mounting holes are distributed in multiple rows, with adjacent rows staggered to achieve a plum blossom arrangement. In the same row, the mounting holes at the edge should extend to the first fracturing zone, the mounting holes in the middle should extend to the top fracturing zone, and the mounting holes between the edge and the middle should extend to the side fracturing zones.

[0052] In the same row, type I fracturers are installed in the mounting holes at the edge, type II fracturers are installed in the mounting holes in the middle, and type III fracturers are installed in the remaining mounting holes. The principle of hole arrangement and placement of fracturers is to ensure that the horizontal projection surface of the rock fracturing range can effectively cover more than 80% of the site plane, and to ensure that in the first fracturing zone, the fracturing range of each layer of the rock mass in the inclined direction of the fracturing disk can be covered and a fracture plane can be formed. After the aforementioned crackers are set up, when observed in the vertical direction, several crackers are distributed in multiple rows, and the crackers in two adjacent rows are staggered to form a plum blossom arrangement, thus forming even-numbered rows of crackers and odd-numbered rows of crackers. Such a staggered arrangement can reduce the overlapping area of ​​the crack surfaces of the two adjacent crackers during the cracking process, thereby increasing the crack area. The crackers in the same row include a type I cracker 1 located at the edge, a type II cracker 11 located in the middle, and a type III cracker 12 located between the type I and type II crackers. All the cracking disks on the same row in the first cracking zone are in a parallel state, and the centers of the cracking disks at the same level on different crackers are in the same plane. Optimally, the cracking disks on the even-numbered rows of crackers in the first cracking zone are orthogonal to the cracking disks on the odd-numbered rows (e.g. Figure 4 、 Figure 11 As shown); in the top fracturing zone, the fracturing disks on the type II fracturing device and the type III fracturing device are all arranged in the horizontal direction, or the fracturing disks on the type II fracturing device and the type III fracturing device are tangent to the top contour surface of the underground project after displacement; in the side fracturing zone, the fracturing disks on the same type III fracturing device are parallel, and the fracturing disks on the left side of the underground project and the fracturing disks on the right side of the underground project in the same row are symmetrically distributed.

[0053] After the Type I, Type II, and Type III fracturers are installed, the multiple fracturing disks of the same fracturer can be segmented vertically. First, the multiple layers of fracturing disks 2 on each Type I, Type II, and Type III fracturer in the first fracturing zone 13 are divided into at least two sections. The first vertically uppermost fracturing disk is detonated to form a permanent fracturing zone in the upper layer, and the remaining multiple fracturing disks are detonated to form immediate fracturing zones in the lower layer. Second, all fracturing disks of the Type II fracturer 11 and all fracturing disks of the Type III fracturer 12 in the second fracturing zone are divided into one section. After all the fracturing disks in the first fracturing zone 13 have been detonated, the fracturing disks in the second fracturing zone are detonated and fractured.

[0054] After the rupture disks are segmented and installed, vibration velocity sensors 10 are deployed. The number of vibration velocity sensors 10 is determined within the protected engineering site based on the scope of the protected object. The vibration velocity sensors are evenly distributed, ensuring that: for the first rupture zone, one vibration velocity sensor 10 is located on the inner wall of the mounting hole corresponding to the topmost rupture disk in each rupture disk segment, located in the immediate rupture zone; for the second rupture zone, one vibration velocity sensor 10 is located on the inner wall of the mounting hole above the top rupture zone. The spacing and maximum row spacing of the aforementioned vibration velocity sensors should be less than or equal to the minimum planar dimension of the protected object. When deploying the vibration velocity sensors, a threshold is set to trigger the explosion of the corresponding rupture disk segment. When the sensor senses that the explosion shock wave reaches the explosion threshold, it triggers the explosion and rupture of the corresponding rupture disk segment.

[0055] To minimize the propagation intensity of the explosive stress wave during the initial explosion, after the fracturing device is deployed, the first segment of the fracturing disk on the fracturing device in the first fracturing zone 13 can be explosively fractured, depending on the importance of the protected object and the potential explosion depth, to form the first n layers of rock fracture surface 8. During the explosion, the first detonating cord 601 in the conduit 3 directly ignites the first segment of the detonator and the second detonating cord 602, thereby detonating the explosives in the explosive chamber and forming a permanent fracture surface 8.

[0056] Finally, grouting is performed on the fracture surface 8 through the mounting holes 7. During grouting, polyurea grouting can be performed based on the location of each mounting hole 7, filling the rock mass on the fracture surface 8 with polyurea slurry. Because polyurea has excellent explosion and impact resistance, it forms an effective explosion-resistant layer after hardening. In addition to effectively reflecting the explosion stress wave through the discontinuous interface formed by the rock fracture and the polyurea layer, the polyurea layer also effectively resists rock deformation, further enhancing the rock mass's explosion and penetration resistance. This creates a highly effective upper fracture zone, which serves as a permanent fracture zone.

[0057] After the permanent fracture zone is formed, if the rock mass at that location is hit and explodes, although the permanent fracture zone can effectively reduce the propagation of the explosion stress wave, with the advancement of explosive performance and weapon systems, the propagation intensity of the explosion stress wave is difficult to predict. In order to leave enough protection safety reserves, the explosion shock intensity sensed by the corresponding vibration velocity sensor reaches the set explosion threshold as the trigger condition, and the remaining segments of the fracture disk distributed along the vertical direction can be sequentially explosively fractured. Specifically, when the explosion shock intensity sensed by the preset vibration velocity sensor 10 reaches the lower explosion threshold, the lower explosion threshold is triggered. After the threshold is reached, the explosive fracturing of the next segment of the fracturing disk 2 in the first fracturing zone 13 is continued to form more rock fracture surfaces on the propagation path of the explosion stress wave, thereby obtaining a deeper instant fracturing zone, thereby having the effect of blocking the propagation of the stress wave; when all segments of the fracturing disk in the first fracturing zone 13 are exploded and the explosion impact intensity sensed by the pre-set vibration velocity sensor 10 reaches the corresponding explosion threshold, the last segment of the fracturing disk in the second fracturing zone is detonated to form a gate-shaped fracturing zone or an arch-shaped fracturing zone in the second fracturing zone, thereby achieving a more effective protection effect on underground engineering.

[0058] In other embodiments of the present invention, the rupture disks on the type I rupture device, the rupture disks on the type II rupture device, and the rupture disks on the type III rupture device in the first rupture zone may be distributed at equal distances or at proportional distances.

[0059] The above is only a preferred embodiment of the present invention. Any simple modification, equivalent change and modification made to the above embodiment by any technician familiar with this profession based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A semi-enclosed, actively fracturing underground engineering explosion-proof protective structure, wherein the upper surrounding rock area near the ground is referred to as a first fracturing zone, the surrounding rock area surrounding the underground engineering is referred to as a second fracturing zone, the surrounding rock area at the top of the underground engineering in the second fracturing zone is referred to as a top fracturing zone, and the surrounding rock areas on both sides of the underground engineering in the second fracturing zone are referred to as side fracturing zones, characterized by: An underground engineering explosion-proof protection structure includes a plurality of fracturers arranged in a first fracturing zone and a second fracturing zone. The fracturers located in the first fracturing zone are arranged in multiple rows on a horizontal plane, and adjacent rows of fracturers are staggered. The fracturers in the same row are parallel, and the fracturers in adjacent rows are orthogonal. The fracturers in the same row include type I fracturers located at the edge, type II fracturers located in the middle, and type III fracturers located between the type I and type II fracturers. The fracturers of the type I fracturers are arranged in the first fracturing zone, the fracturers of the type II fracturers are arranged in the first fracturing zone and the top fracturing zone, and the fracturers of the type III fracturers are arranged in the first fracturing zone, the top fracturing zone, and the side fracturing zones. The fracturers include a fracturer filled with explosives and a conduit extending in a vertical direction. After the conduit is connected to the center of the fracturer, the inclination angle of the fracturer in the vertical plane projection is β.

2. The semi-enclosed active fracturing underground engineering explosion-proof protection structure according to claim 1, characterized in that: A first detonating cord extending in a vertical direction is provided in the cavity of the catheter. The cavity inside the rupture disk includes an annular explosive chamber arranged on the periphery of the rupture disk and used for burying explosives, and an annular detonator chamber arranged between the explosive chamber and the catheter and used for arranging detonators. The explosive chamber and the detonator chamber are in a connected state. A second annular detonating cord is provided in the explosive chamber, and the detonating joint of the second detonating cord and the detonating joint of the detonator are both connected to the first detonating cord.

3. The semi-enclosed active fracturing underground engineering explosion-proof protection structure according to claim 2, characterized in that: The middle portion of the outer wall of the rupture disk is recessed toward the direction close to the catheter so that the outer wall of the rupture disk is arranged in a "V" shape.

4. The semi-enclosed active fracturing underground engineering explosion-proof protection structure according to claim 1, characterized in that: The inclination angles of the fracture disks on the Type II and Type III fracture devices in the top fracture zone are both 90°. The inclination angles of the fracture disks on the same Type III fracture device in the side fracture zone are the same, and the inclination angle β of the fracture disks on one side of the underground project in the same row is a small angle of 0-5°, while the inclination angle of the fracture disks on the other side of the underground project is (180°-β).

5. The semi-enclosed active fracturing underground engineering explosion-proof protection structure according to claim 1, characterized in that: The inclination angles of the fracture disks on the Type II and Type III fracture devices in the top fracture zone should meet the following requirements: when the top contour surface of the underground project deviates upward to pass through the center of the fracture disk, the corresponding fracture disk is tangent to the top contour surface after the deviation; the inclination angles of the fracture disks on the same Type III fracture device in the side fracture zone are the same, and the inclination angle β of the fracture disks on one side of the underground project in the same row is a small angle of 0-5°, and the inclination angle of the fracture disks on the other side of the underground project is (180°-β).

6. The semi-enclosed active fracturing underground engineering explosion-proof protection structure according to claim 1, characterized in that: The lowest fracturing disk on the Type II fracturing device in the top fracturing zone is required to be at least 1 / 2 of the underground engineering cavern span size away from the top of the underground project; the fracturing disk on the Type III fracturing device adjacent to the Type II fracturing device in the side fracturing zone is required to be at least 1 / 2 of the underground engineering cavern span size away from the side of the underground project.

7. A semi-enclosed active fracturing method for underground engineering explosion protection, characterized by: The method is implemented based on uniformly arranging a semi-enclosed active fracturing underground engineering explosion-proof protection structure as described in any one of claims 1 to 6 in the protection area. The specific process is as follows: S1: Calculate the installation hole position and depth of the fracturing device and the size of the fracturing disk on the fracturing device according to the shape of the building structure to be protected; S2: After determining the depth of the mounting holes, drill the holes. The resulting horizontal projections of the mounting holes are arranged in multiple rows, with adjacent rows staggered to form a plum blossom arrangement. In the same row, the mounting holes at the edge should extend to the first cracking zone, the mounting holes in the middle should extend to the top cracking zone, and the mounting holes between the edge and the middle should extend to the side cracking zone. S3: Install Type I crackers in the mounting holes at the edge of the same row, install Type II crackers in the mounting holes in the middle, and install Type III crackers in the remaining mounting holes. The multiple crack disks of the same cracker are vertically segmented. First, the multiple layers of crack disks on each Type I, Type II, and Type III cracker in the first cracking zone are divided into at least two sections. The first vertically uppermost cracking disk is detonated to form a permanent cracking zone in the upper layer, and the remaining multiple cracking disks are detonated to form an immediate cracking zone in the lower layer. Second, all the cracking disks of the Type II cracker in the second cracking zone and all the cracking disks of the Type III cracker in the second cracking zone are divided into one section. S4: Deploying vibration velocity sensors on the inner wall of the mounting holes corresponding to each rupture disk in the first rupture zone and on the inner wall of the mounting holes corresponding to the uppermost rupture disk in the second rupture zone, and setting thresholds for triggering rupture disk explosion for the vibration velocity sensors; S5: explosively fracturing the first segment of the fracturing disk on the fracturing device in the first fracturing zone to obtain a permanent fracturing zone; S6: When the explosion impact intensity sensed by the corresponding vibration velocity sensor reaches the set explosion threshold, the remaining segments of the fracture disks distributed along the vertical direction in the first fracture zone are sequentially subjected to segmented explosive fracture to form a deeper instant fracture zone. After all the fracture disks in the first fracture zone are exploded, the fracture disks in the second fracture zone are subjected to explosive fracture.

8. The semi-enclosed active fracturing underground engineering explosion protection method according to claim 7, characterized in that: In step S3, after the fracturing devices are installed in the installation holes, the centers of the fracturing disks at the same level on the fracturing devices are located on the same plane.

9. The method for underground engineering explosion protection with semi-enclosed active fracturing according to claim 7, characterized in that: In step S4, the vibration velocity sensors in the first fracturing zone are arranged in the immediate fracturing zone and on the inner wall of the mounting hole corresponding to the uppermost fracturing disk in each fracturing disk, and the maximum value of the spacing and row spacing of the vibration velocity sensors is less than or equal to the minimum size of the protected underground project on the plane.

10. The semi-enclosed active fracturing underground engineering explosion protection method according to claim 7, characterized in that: In step S5, after explosive fracturing of the first segment of the fracturing disk on the fracturing device in the first fracturing zone, grouting is performed on the fracture surface through the mounting hole to obtain a permanent fracturing zone.

Images