Medium-length hole blasting method for cooperatively controlling air blasting and hole collapse

Abstract

The invention provides a medium-length hole blasting method for cooperative control of air blasting and hole collapse, and relates to the technical field of underground mine blasting engineering.The medium-length hole blasting method comprises the following steps that S1, geological and structural information of an underground mine stope to be mined is obtained; s2, dividing a medium-length blast hole function section; s3, designing a charging system: constructing a structure coupling blasting configuration system based on the synergistic effect of a blasting section, an air blasting section and a hole collapse section; s4, setting an initiation system and delay; and S5, blasting implementation. According to the method, function division in the drilling space is redefined, a collapse-air coupling system is established, directional management and control over the detonation pressure release path and structure-level protection over the protection target are achieved, the structure bottleneck of blasting disturbance control in the prior art is broken through, and the reliability of blasting disturbance control is improved. And the safety, the stability and the adaptability of medium-length hole blasting under complex geological conditions are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of underground mine blasting engineering, and in particular to a medium-deep hole blasting method with coordinated control of air blasting and hole collapse, and more particularly to an underground medium-deep hole blasting method that achieves controlled release of blasting disturbance and directional isolation of protective structures by deploying active air blasting sections and induced hole collapse sections in a hole collapse risk environment. Background Art

[0002] In underground mines, deep hole blasting is an important means of crushing ore and rock masses and achieving efficient collapse. It is widely used in various ore mining methods, such as open-site method stage mining, ore-retention method pillar mining, and staged collapse method. In particular, in upward fan-shaped medium- and deep-hole blasting, its hole distribution system has significant advantages such as concentrated charging, high blasting efficiency, and precise roof collapse. However, in typical adverse geological conditions such as underground broken zones, weak zones of surrounding rock, or structurally broken rock masses, medium- and deep-hole drilling is prone to unstable behaviors such as hole collapse, hole shrinkage, hole wall shedding, and hole bottom closure. Once these problems occur, they will directly lead to failure of explosive filling, deviation of detonation position, and disorder of explosive pressure release path, which will seriously weaken the blasting effect and even cause safety risks such as partial ore body residue, flying rocks, tunnel impact, or pillar damage.

[0003] To address the problem of hole collapse, current projects generally adopt measures such as lengthening the wall protection pipe, rapid charging construction, sealing the bottom, and air cushioning in the non-charged section. However, these methods generally have the following limitations: (1) high cost and high process requirements, which increase the complexity of on-site organization; (2) lack of design ideas for functional reuse of the collapsed hole section, which makes the collapsed hole section always in an "invalid space" state; (3) it is impossible to actively control the propagation direction and release method of the blasting energy in space, especially when it is close to the mine pillars, tunnels, temporary support and other areas, making it difficult to achieve fine control of the disturbance effect.

[0004] At the same time, although the traditional "air gap" technology can buffer the release of explosive pressure through a non-charged cavity, the structure is usually not accurately positioned, has weak reflection control capabilities, and cannot be synergistically coupled with the natural collapse hole structure, resulting in the inability to effectively and directionally release or reflect and attenuate the explosive pressure energy in three-dimensional space. Its energy control effect is difficult to meet the safety requirements of complex explosion areas.

[0005] In view of this, it is necessary to study a medium-deep hole blasting method with coordinated control of air blasting and hole collapse to solve the above technical problems. Summary of the Invention

[0006] In view of the technical problems existing in the background technology, the present invention provides a medium-deep hole blasting method that integrates the layout and control strategy of the induced collapse hole section with the active air blasting section structure, that is, a medium-deep hole blasting method for underground mines based on the coordinated control of the air blasting section and the induced collapse hole. By redefining the functional division inside the drilling space and establishing a "collapse-air" coupling system, directional control of the explosion pressure release path and structural-level protection of the protection target are achieved, breaking through the structural bottleneck of the existing technology in blasting disturbance control, and improving the safety, stability and adaptability of medium-deep hole blasting under complex geological conditions.

[0007] The present invention provides a medium-long hole blasting method with coordinated control of air blasting and hole collapse, comprising the following steps: S1, obtain geological and structural information of the underground mine site to be mined; S2, Functional Segmentation and Layout of Medium-Long Hole Blastholes: Re-divide the borehole space into three functional segments: blasting segment, airblast segment, and hole collapse segment. Layout of each functional segment is performed, including the placement and guidance of the hole collapse segment, the location and length optimization of the airblast segment, and the design of the charge support structure. S3, charging system design: The three types of functional segments in step S2 are combined and arranged according to the spatial response logic to construct a structural coupling blasting configuration system based on the synergistic effect of the blasting segment, the air blast segment, and the collapse hole segment. This system can achieve active control of the main propagation path of the explosion pressure wave and structural segmented response of the energy release process. S4, detonation system setting and delay setting; S5, blasting implementation.

[0008] As a further improvement of the present invention, in step S2, the collapsed hole section is a natural or artificially constructed non-charged filling body; The layout of the induced collapse hole section is selected in the following three sections: first, the energy transition section between the main blasting section and the protection area; second, the boundary position close to the pillars, tunnels, and rock masses that should not be disturbed; third, the rock mass RQD Low, sudden drilling speed changes during construction, and weak sections with difficult wall protection; The induction strategy for the collapsed hole section is to make the collapsed hole section unstable and collapse in advance before explosion through induction methods, forming a natural non-charged isolation zone; the induction methods include one or a combination of water injection softening induction method, bottom hole explosion disturbance induction method, and light disturbance excitation induction method.

[0009] As a further improvement of the present invention, in step S2, the air-blast section is a non-blasting section in the blast hole where no explosives are loaded; The position of the airblast section is arranged on the main propagation path of the explosion pressure wave, close to the structural protection object but with a predetermined energy dissipation buffer distance. The specific position is calculated according to the following formula: ; in: L ae is the distance from the starting position of the air burst section to the orifice; L is the depth of a single blast hole; D p is the vertical distance from the bottom of the hole to the protective structure; θ is the blasthole inclination angle; δ1 is the structural safety buffer correction, generally 0.4~0.6m; δ2 is the back pressure peak extension correction value, which is set according to the explosion pressure intensity and is taken as 0.3~0.5m; ξ c is the coupling correction value of the collapsed hole section below, which is set to 0.3~0.5m. If there is no collapsed hole section, it is 0; λ g is the correction coefficient for rock mass influence, ranging from 0.1 to 0.5, and is related to the structural surface density and water saturation; R g is the comprehensive structural disturbance index of rock mass, which is composed of joint density, RQD , weighted calculation of surrounding rock grade; Structural protection objects, in this invention, generally refer to engineering physical structures that need to be protected during blasting operations to avoid disturbance or damage, mainly including adjacent pillar structures, tunnel surrounding rocks, upper and lower plate stable structural layers (top pillars, bottom pillars), sensitive areas close to goafs or boundary rock masses, etc.

[0010] As a further improvement of the present invention, in step S2, the calculation model for optimizing the length of the airburst section is as follows: ; in: L c is the length of the air burst section, m; E b is the unit explosive energy of the upper blasting section, MJ / m; R t is the explosion pressure path impedance coefficient (calculated from rock density and wave velocity); K v is the rock mass vibration response coefficient, which is comprehensively determined through on-site vibration testing; L cz is the length of the collapsed section below; α, β, and γ are weight and bias factors, which are selected according to the on-site structural target fitting value: α=0.8, β=0.3, and γ=0.2; In addition, considering the objective effects of blasting fragmentation, blasting vibration, and depletion loss in medium and deep hole blasting, the setting of the air blast section is generally smaller than the length of the lowest resistance line under equivalent spherical charge blasting, that is, between 1.0 and 1.5m.

[0011] As a further improvement of the present invention, the charge support structure design of the air-blast section in step S2 includes: in terms of structural configuration, the air-blast section is designed as a non-charge space, and its upper and lower boundaries are clearly distinguished from the blasting section or the collapsed hole section to form an "air cavity partition zone" with a physical separation effect; low-density disturbance material is selectively filled in the cavity to form a controllable explosion pressure buffer medium.

[0012] As a further improvement of the present invention, the charge support structure design of the air-blast section also includes: in terms of the charge column structure, the air-blast section adopts a whole-tube positioning charge column structure, and its upper and lower charge columns are precisely fixed to the upper and lower edges of the air-blast section by charge tube limiting rings and friction locators to form a stable two-way boundary; the air-blast section is partially hollow and not charged, and a lightweight filling material or an isolation cavity is arranged in the cavity to enhance the reflection and dissipation effect of the explosion pressure wave; in order to prevent the charge column from sinking or structural displacement, a hanging anchoring device is arranged at the orifice to form an upper support point, so as to realize spatial directional separation and stable positioning of the charge column structure.

[0013] As a further improvement of the present invention, the design of the charging support structure of the air-blast section also includes: in terms of charging method, the main explosion section above the air-blast section adopts a segmented charging strategy, and for areas requiring high control precision, a "clamp-controlled bidirectional initiation" structure is adopted, and detonator excitation sources are respectively arranged above and below the air-blast section to construct a clamp-controlled path for the explosion pressure wave.

[0014] As a further improvement of the present invention, in step S3, the structural coupling blasting configuration system adopts a "collapse-empty-loaded-empty-collapse" configuration, and the structural design is: the blasting section is located in the middle of the hole, and the air blasting sections located above and below the blasting section constitute a directional back pressure zone, and collapsed hole sections are arranged at both ends as peripheral energy absorption belts, and the overall three-layer response system of the blasting structure of "blasting pressure release core-back pressure buffer layer-disturbance energy absorption belt" is constructed.

[0015] As a further improvement of the present invention, in step S3, the structural coupling blasting configuration system adopts an "empty-loaded-collapse" configuration, and the structural design is: the blasting section is arranged in the middle section of the hole, the lower part is the prone to collapse area or the artificially induced collapse hole section, and the upper part is the air blasting section back pressure control body.

[0016] As a further improvement of the present invention, the structural coupling blasting configuration system adopts a "collapse-load-empty" configuration, and the structural design is: the collapsed hole section is arranged at the bottom of the hole, the upper part is the air blasting section, and the blasting section is embedded therein.

[0017] As a further improvement of the present invention, in step S3, the structural coupling blasting configuration system adopts an "empty-loaded-empty" configuration, and the structural design is as follows: the blasting section is sandwiched between two air blasting sections, and the blasting pressure is reflected and reflected in a limited space, and is released laterally after being focused multiple times.

[0018] As a further improvement of the present invention, the structural coupling blasting configuration system adopts "collapse-install-collapse", and the structural design is: the blasting section is sandwiched between the collapse hole sections of the upper and lower natural energy absorption zones, and no air blast section is provided, and the blast pressure is purely attenuated by relying only on the collapse hole section.

[0019] Beneficial effects: 1. The medium- and deep-hole blasting method for coordinated airblast and hole collapse control provided by this invention is suitable for structural energy control in medium- and deep-hole blasting systems in underground mines. It is particularly suitable for medium- and deep-hole drilling systems with complex geological conditions, prone to rock collapse, and high structural protection requirements. By constructing a coupled structure of active airblast sections and induced hole collapse sections, the method achieves the spatially directed release and progressive weakening of blasting disturbance energy, as well as structural protection of the target section. This method redivides the borehole space into functional zones, proposing three structural zone definitions (blasting section, airblast section, and hole collapse section). Based on engineering parameters, it guides segment identification, optimizes airblast locations, controls induced hole collapse methods, and constructs structural combination patterns, forming a multi-dimensional blasting energy control system that integrates identification, layout, activation, and regulation.

[0020] 2. The medium-deep hole blasting method with coordinated control of air blasting and hole collapse proposed in the present invention is a medium-deep hole blasting method that integrates the layout and control strategy of the induced hole collapse section with the structure of the active air blasting section. By redefining the functional division inside the borehole space and establishing a "collapse-air" coupling system, it realizes directional control of the explosion pressure release path and structural-level protection of the protection target, breaking through the structural bottleneck of the existing technology in blasting disturbance control, and improving the safety, stability and adaptability of medium-deep hole blasting under complex geological conditions.

[0021] 3. The proposed method for medium- to deep-hole blasting, combining coordinated control of airburst and hole collapse, and the resulting multi-element coupled blasting structure, not only transcend the traditional linear "charge segment" layout of blasting configurations, but also, through the collaborative design of "structural functional segmentation" and "response path control," creates an integrated blasting energy control system with multiple functions, including physical isolation, energy segmentation, disturbance targeting, and structural protection. This system is particularly suitable for underground medium- to deep-hole blasting environments characterized by high rock fragmentation, complex protection requirements, and high spatial controllability. It represents one of the core technical approaches to achieving the "energy control, pressure control, and disturbance control" system objectives for the blasting process.

[0022] 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 specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings used in the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0024] Figure 1 Schematic diagram of the process structure of a medium-long hole blasting method with coordinated control of air blasting and hole collapse provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of the blasthole structure of the medium-deep hole blasting method with coordinated control of air explosion and hole collapse provided by an embodiment of the present invention.

[0025] Description of reference numerals: 1-rock in the collapsed hole section; 2-friction locator; 3-detonator; 4-foot line; 5-air burst section (filled with foamed expanded clay); 6-charging section (blasting section, explosives). DETAILED DESCRIPTION

[0026] The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions.

[0028] In the description of the embodiments of the present invention, technical terms such as "first" and "second" are used solely to distinguish between different objects and should not be understood to indicate or imply relative importance or to implicitly specify the quantity, specific order, or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present invention, "plurality" means more than two, unless otherwise specifically defined.

[0029] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In the description of the embodiments of the present invention, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exists simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0031] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0032] In the description of the embodiments of the present invention, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present invention.

[0033] In the description of the embodiments of the present invention, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0034] This invention provides a structural energy control method for medium- to long-hole blasting systems in underground mines. It is particularly suitable for medium- to long-hole drilling systems with complex geological conditions, prone to rock collapse, and high structural protection requirements. By constructing a coupled structure with an active airblast section and an induced collapse section, this method achieves the spatially directed release and progressive weakening of blasting disturbance energy, while also protecting the structure of the target section. This method redivides the borehole space into functional zones and defines three structural regions: blasting section, airblast section, and collapse section. Based on engineering parameters, this method guides segment identification, optimizes airblast locations, controls induced collapse methods, and constructs structural combination patterns, forming a multi-dimensional blasting energy control system that integrates identification, placement, activation, and regulation.

[0035] See also Figure 1 As shown, the present invention provides a medium-long hole blasting method with coordinated control of air explosion and hole collapse, which includes the following steps: S1, obtain geological and structural information of the actual underground mine site to be mined; S2, Functional Segmentation and Layout of Medium-Long Hole Blastholes: The borehole space is re-divided into functional segments, and structural regional definitions of three functional segments, namely the blasting segment, the airblast segment, and the hole collapse segment, are proposed. The layout of each functional segment is then carried out, including the layout and guidance of the hole collapse segment, the location layout and length optimization of the airblast segment, and the design of the charge support structure. S3, charging system design: The three types of functional segments in step S2 are combined and arranged according to the spatial response logic to construct a structural coupling blasting configuration system based on the synergistic effect of the blasting segment, the air blast segment, and the collapse hole segment. This system can achieve active control of the main propagation path of the explosion pressure wave and structural segmented response of the energy release process. S4, detonation system setting and delay setting; S5, blasting implementation.

[0036] In some specific embodiments, the specific process of functional division, definition and layout of the space in the medium-long hole blasthole in step S2 is as follows: To achieve structural function control and energy directional management during medium- and long-hole blasting, this invention classifies and divides the internal space of the blasthole according to engineering functional requirements, constructing a blasting structure system with coordinated multifunctional segments. Based on the rock mass structural characteristics, construction feedback, and blasting target differences, the blasthole space is divided into the following three basic functional segments: (1) Blasting section The blasting section is the area in the blasthole with good surrounding rock stability and safe placement of explosive columns. Its design target is the main energy release area and the core rock breaking section. The surrounding rock in this section is intact. RQD High, low joint density, continuous drilling, no collapse or shrinkage of the hole wall, smooth transmission of explosive pressure, no structural blockage or weak interface, and sufficient buffer distance from the protection target or structure boundary.

[0037] This section is the main charging area and the main control section for crushing efficiency and fragmentation control. The charge distribution and detonator timing structure need to be designed in combination with the rock properties and blasting area morphology.

[0038] (2) Air blast section An airblast section is a non-explosive section within a blasthole designed to be uncharged. Its primary functions are to control the directional release of explosive pressure energy, construct a backpressure wave field, and mitigate structural disturbances. Airblast sections are typically located in the following locations within a blasthole: between the blast section and the structure to be protected; in sections prone to collapse but not prone to inducing collapse; and at interface areas where directing explosive pressure reflection or energy attenuation is required.

[0039] The airburst section is unloaded, with the charge column above it held in place by a fixture or cartridge. The cavity can optionally be filled with a weakly reflective material (such as foamed ceramsite) to enhance control. This section, combined with the collapse section, forms a composite "energy control and energy absorption" system.

[0040] It should be noted that the airblast section described in this invention differs from conventional air gap structures. While air gaps are often used to enhance blasting efficiency, the airblast section in this invention is a structural energy-control component designed to guide the direction of explosive pressure, reduce peak disturbances, and, in conjunction with the collapse hole section, form a spatial isolation system. It possesses independent structural functionality and is protectively oriented.

[0041] (3) Collapse section The collapsed section is the rock filling area in the blasthole formed by natural collapse during drilling or induced rock fragments. This section is discontinuous and cannot be stably charged, and it usually forms before blasting. The collapsed section is a natural or artificial "non-charged fill" that has the structural functions of absorbing explosive pressure energy, damping waves, and reducing vibrations. This section is used to protect the ore pillar, control the disturbance boundary, and reduce blasting hazards.

[0042] In some specific embodiments, the layout and control strategy of the induced collapse section in step S2 is as follows: In medium- and deep-hole blasting, to address the issues of weak surrounding rock structure and developed joints in complex geological conditions, leading to unstable borehole walls and prone to collapse, this invention introduces an "induced collapse section" as an auxiliary control section in the blasting configuration. This section aims to transform the previously uncontrollable, random occurrence of collapse into a manually controlled, spatiotemporally controlled structural behavior. By inducing the collapse of the borehole section before blasting, it creates a natural, non-charged isolation zone, thereby preventing structural interference caused by collapse on charging, detonation, and blast pressure propagation. Furthermore, it forms a blast pressure attenuation node at a specific location.

[0043] The layout of the induced collapse hole section is usually selected in the following three sections: First, the energy transition section between the main blasting section and the protected area; Second, it is located near the boundary of pillars, tunnels, and rock masses that should not be disturbed; Third, rock mass RQD A weak section with a low drilling speed, sudden changes in drilling speed during construction, and difficulty in wall protection. This section is not charged after installation and is considered a natural non-charged section.

[0044] In order to achieve the "early, stable and directional" formation of the collapse hole, three ways of inducing collapse holes are designed: (1) Water injection softening induction method This method is particularly effective when the rock mass contains argillaceous cement, significant foliation, or soluble minerals (such as mudstone, argillaceous sandstone, and clay interlayers). Fresh water is injected into the induction borehole section via a water injection pipe or pressure pump, at a rate of 50% of the borehole volume, within 48 hours before blasting. By injecting water into the designed collapse section, water enters the joints and microcracks of the borehole wall, causing the rock mass to soften, expand, or decrease in shear strength, potentially inducing self-weight shear failure or structural instability.

[0045] (2) Bottom hole explosion disturbance induction method This method is primarily suitable for areas with well-developed surrounding rock joints and fractured rock mass but strong self-stabilization capabilities. It can also be used when traditional water injection is ineffective. Using a high-pressure inert gas release device (such as a liquid CO2 explosion gun), an instantaneous gas wave is released at the bottom or middle of the hole. The high-pressure gas wave generates a localized airburst wave field within the hole, causing disturbance acceleration on the hole wall, causing weak rock blocks to slip, joints to open, and instability to occur.

[0046] (3) Light perturbation excitation induction method This method is primarily applicable when structural stability is critical, the potential for collapse is low, and a clear time window for collapse control is required. A lightly charged airblast section is reserved above this section. A short-term excitation (vibration duration 30 seconds to 2 minutes, delayed single-point detonation with airblast) is performed 12 hours before blasting. External disturbances are transmitted to the induction zone via explosive gas waves or low-frequency mechanical waves, triggering stress redistribution within the structure and causing the potentially unstable body to slide and fall.

[0047] The above three methods can be selected according to geological conditions, or they can be deployed jointly in the same induction section. First, the structure is softened and weakened by water injection, and then rapid collapse is promoted through disturbance excitation, forming a coordinated induction system from "structural pre-weakening" to "dynamic triggering", ensuring the timeliness, controllability and directionality of the collapsed hole, and creating a clear boundary and spatial foundation for the subsequent blasting configuration arrangement.

[0048] In some specific embodiments, the specific process of air burst section layout optimization and charge structure design in step S2 is as follows: The airblast section, a non-charged space segment with structural functions, is one of the more critical functional sections of the blasthole structure. It fulfills multiple roles, including blast pressure reflection, disturbance barrier, energy path diversion, and protective interface construction. Rather than simply being left empty, this section is an energy-control unit collaboratively designed across multiple dimensions, including spatial location, structural maintenance, charge coordination, and sequential detonation. It serves as a crucial "energy response node" in the blasting path.

[0049] In terms of space, the layout of the airblast section should meet the following principles: ① Directional effect, which must be located on the main propagation path of the explosive pressure and can regulate the direction of the explosive energy; ② Structural protection, which needs to be deployed at the structural interface between the blast area and the protected target; ③ Energy reflection, combined with the collapsed hole structure, forms a reentrant wave field, changing the propagation direction of the explosion stress wave; ④ Layout independence: it must be separable and identifiable in space and functionally non-equivalent to other functional segments.

[0050] (1) Calculation of the airblast section setting position The airblast section should be set on the main propagation path of the explosion pressure wave, close to the structure to be protected but with sufficient energy dissipation buffer distance. Its setting position can be calculated according to the following formula: ; in: L ae - Distance from the starting position of the airblast section to the orifice; L- single blasthole depth; D p - Vertical distance from the bottom of the hole to the protective structure; θ-blasthole inclination; δ1-structural safety buffer correction, generally 0.4~0.6m; δ2-back pressure peak extension correction value, set according to the explosion pressure intensity, take 0.3~0.5m; ξ c - The coupling correction value of the collapsed hole section below is 0.3~0.5m, and is 0 if there is no collapsed hole section; λ g - Rock mass influence correction coefficient, ranging from 0.1 to 0.5, is related to the structural surface density and water saturation; R g - Rock mass comprehensive structural disturbance index, which is composed of joint density, RQD , weighted calculation of surrounding rock grade The energy isolation effect is comprehensively balanced through reverse iteration, and the position of the air-blast section is reasonably determined in space.

[0051] (2) Optimization model for the layout length of the airblast section The length of the airblast section determines its energy control volume and reflex range. The length should be coordinated with the coupling structure of the upper and lower spaces of the airblast section, the elastic properties of the rock mass, and the energy release form. This paper proposes the following length optimization calculation model: ; in: L c - Length of air burst section, m; E b - Unit explosive energy of the upper blasting section, MJ / m; R t- Explosion pressure path impedance coefficient (calculated by rock density and wave velocity); K v - Rock mass vibration response coefficient, determined comprehensively through field vibration testing, etc.; L cz - Length of the lower collapsed section; α, β, γ - weight and bias factors, which are selected according to the on-site structural target fitting (recommended α=0.8, β=0.3, γ=0.2).

[0052] In addition, considering the objective effects of medium and deep hole blasting, such as blasting block size, blasting vibration, and depletion loss, the air blast section should not be too long, and is generally less than the length of the lowest resistance line under equivalent spherical charge blasting, that is, between 1.0 and 1.5 meters.

[0053] (3) Design of airblast section structure and charge initiation system adaptation In order to ensure that the air-blast section effectively assumes the directional energy control function in medium-deep hole blasting, the present invention has carried out system adaptation design for its structural configuration, charging method and initiation system, so that it has clear spatial separation, stable structural support and response coordination capabilities, and constructs a complete energy control subsystem.

[0054] In terms of structural configuration, the airburst section is designed as a non-charged space, with its upper and lower boundaries clearly separated from the blasting or collapse section, forming a physically separated "air cavity isolation zone." The length of the airburst section is calculated according to the aforementioned formula and determined based on the energy reflection requirements and the coordination with the collapse section. To enhance the backpressure effect, low-density disturbance materials (such as ceramsite foam or compressed foam) can be added to the cavity to form a controllable explosion pressure buffer.

[0055] In terms of the charge column structure, to address the problem of charge column sliding caused by the empty burst section, a "whole-tube positioning charge column structure" is adopted. This means that the empty burst section of the pre-loaded charge tube is left empty and unloaded, and the upper and lower sections of the charge column are arranged continuously. The entire section is positioned at the upper edge of the empty burst section using a charge tube limit ring and friction locator, and a hanging anchor device is installed at the hole mouth to form an upper support. If necessary, the lower section of the charge tube can use the debris from the collapsed hole section to naturally form a supporting base. It is stably suspended in the "upper limit position-lower support bottom" clamping configuration, ensuring the precise positioning of the charge section and the stability of the overall structure, eliminating the need for complex operations in the hole.

[0056] Specifically, the upper and lower explosive columns are precisely fixed to the upper and lower edges of the air-blast section by the charge tube limit ring and the friction locator, forming a stable two-way boundary; the air-blast section is partially hollow and not loaded with explosives, and a lightweight filling material or an isolation cavity is set in the cavity to enhance the reflection and dissipation effect of the explosion pressure wave; in order to prevent the charge column from sinking or structural displacement, a hanging anchor device is set at the hole mouth to form an upper support point, so as to realize spatial directional separation and stable positioning of the charge column structure.

[0057] In terms of charging, a segmented charging strategy is employed in the main blast section above the airblast section, increasing charge density by 10% and ensuring peak offset with the energy wavefronts of other sections. For areas requiring high control precision, a "clamp-controlled bidirectional initiation" structure can also be employed, placing detonator excitation sources above and below the airblast section to create a clamp-controlled path for the explosive pressure wave, further enhancing energy reentry and disturbance isolation.

[0058] Through the highly coupled design of the above-mentioned structural configuration-charging system-timing control, the air-blast section not only exists as a non-charging area, but also becomes an important response unit for controlling the direction of explosion pressure propagation, weakening energy intensity, and protecting the structural boundary. It is the key technical support in the multifunctional blasting energy control structure of the present invention.

[0059] In some specific embodiments, the specific process of the structure-coupled blasting configuration and arrangement in step S3 is as follows: In order to achieve multi-objective coordinated control of directional energy control, disturbance reduction and structural protection in medium- and deep-hole blasting in complex spatial structures, the present invention proposes a structural coupling blasting configuration system based on the coordinated action of charging section, airblast section and collapsed hole section. By combining and arranging the three types of functional sections according to spatial response logic, active control of the main propagation path of the explosion pressure wave and structural segmented response of the energy release process can be achieved, while maintaining the blasting intensity, its safety and precision control capabilities are significantly improved.

[0060] The main combination layout configurations are as follows: See also Figure 2 As shown in the figure, in the "collapse-empty-charge-empty-collapse" configuration, the structural design is as follows: the main blasting charge section (blasting section) is located in the middle of the hole, the air blast sections above and below it form a directional counter-pressure zone, and the collapsed hole sections are arranged at both ends as peripheral energy absorption belts. The overall structure constructs a three-layer response system of the blasting structure: "blasting pressure release core - counter-pressure buffer layer - disturbance energy absorption belt." This configuration is suitable for use when the blasting zone is located in the middle of the ore body and is adjacent to protected objects above and below (such as the roof support area or the footwall goaf). The air blast section reflects the wave back to limit the disturbance path, while the collapsed hole section deeply absorbs the remaining energy, achieving "directional release and symmetrical energy dissipation" of the blasting pressure in space, ensuring crushing efficiency while controlling boundary disturbances.

[0061] In the "empty-loaded-collapse" configuration, the structural design is as follows: the charging section (blasting section) is arranged in the middle section of the hole, the lower part is the prone-to-collapse area or the artificially induced collapse area, and the upper part is the air-blast section back-pressure control body. After detonation, the explosive pressure wave encounters the air-blast section upward, generating a wave field reversal, propagating downward to the collapsed hole section and gradually attenuating, thus achieving precise sealing and control of the disturbance below. This configuration is particularly suitable for scenarios where there are goafs or unstable floor structures in the footwall. It can prevent the explosive pressure from penetrating and affecting the lower facilities. At the same time, the wave field reversal formed in the air-blast section enhances the energy focusing of the charging section, making it suitable for operations such as roof collapse and counter-layer delivery.

[0062] In the "collapse-charge-empty" configuration, the structural design involves placing a collapsed hole section at the bottom of the hole, with an air-blast section at the top, and a charge section (blasting section) embedded within. This structural design utilizes the collapsed hole section to provide natural bottom resistance, preventing excessive downward expansion of explosive pressure. Simultaneously, the upper air-blast section forms a counter-pressure interface, achieving the goal of concentrating explosive energy laterally or centrally. This design is suitable for scenarios where the upper structure is sensitive (such as roadways and track areas) but the lower structure is stable and collapsible. The combination of "bottom energy restraint and top vibration limiting" effectively prevents the spread of explosive pressure peaks toward the upper and lower structural interfaces.

[0063] In the "air-load-air" configuration, the main blast section (blasting section) is sandwiched between two air-blast sections. The blast pressure is reflected and reflected within a confined space, focused multiple times, and then propagated and released laterally. This configuration is commonly used in scenarios such as rock protection and narrow space collapse control. By constructing a wave field system with "centrally focused energy and upper and lower limit release," the structural disturbance is concentrated in the target blast area, greatly improving the directional control effect while preventing the spread of peripheral disturbances.

[0064] Furthermore, in configurations such as "collapse-load-collapse," the structure is designed so that the blasting section is sandwiched between upper and lower natural energy absorption zones. Without an airblast section, the blasting pressure is purely attenuated by the collapse hole section. This is suitable for conditions requiring high controllability of the collapse hole, limited structural layout, or high cost control requirements. While the pressure control capability is not as precise as with airblast coupling, the structure is simple, adaptable, and highly practical on-site.

[0065] Through this multi-configuration design, the multi-element coupled blasting structure constructed by this invention not only transcends the traditional linear "charge segment" layout of blasting configurations, but also, through the collaborative design of "structural functional segmentation" and "response path control," creates an integrated blasting energy control system with multiple functions, including physical isolation, energy segmentation, disturbance targeting, and structural protection. This system is particularly suitable for underground medium- and deep-hole blasting environments with high rock fragmentation, complex protection requirements, and high spatial controllability. It represents one of the core technical approaches to achieving the "energy control, pressure control, and disturbance control" system goals of the blasting process.

[0066] In summary, the present invention provides a medium-deep hole blasting method with coordinated control of air blasting and hole collapse, which relates to the field of underground mine blasting engineering technology, and specifically to an underground medium-deep hole blasting method that achieves controlled release of blasting disturbance and directional isolation of protective structure by deploying active air blasting sections and induced hole collapse sections in a hole collapse risk environment. It specifically includes the following steps: S1, obtaining geological and structural information of the underground mine stope to be mined; S2, division and layout of functional sections of medium and long hole blastholes: re-dividing the borehole space into functional section partitions, proposing structural area definitions of three functional sections: blasting section, air blasting section, and collapsed hole section, and laying out each functional section, including the layout and control strategy of the induced collapsed hole section, the layout optimization of the air blasting section, and the charging structure design; S3, charging system design: combining and arranging the three types of functional sections in step S2 according to the spatial response logic, constructing a structural coupling blasting configuration system based on the synergistic effect of the blasting section, air blasting section, and collapsed hole section, to achieve active control of the main path of the explosion pressure wave propagation and the structural segmented response of the energy release process; S4, detonation system setting and delay setting; S5, blasting implementation. The present invention redefines the functional division within the borehole space and establishes a "collapse-void" coupling system to achieve directional control of the explosive pressure release path and structural-level protection of the protected target, breaking through the structural bottleneck of existing technologies in blasting disturbance control and improving the safety, stability and adaptability of medium- and deep-hole blasting under complex geological conditions.

[0067] It should be noted that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the technical solution of the present invention are all included in the technical scope of the present invention. In addition, without departing from the scope of the present invention, other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A medium-long hole blasting method with coordinated control of air blasting and hole collapse, characterized in that: The steps include: S1, obtain geological and structural information of the underground mine site to be mined; S2, Functional Segmentation and Layout of Medium-Long Hole Blastholes: Re-divide the borehole space into three functional segments: blasting segment, airblast segment, and hole collapse segment. Layout of each functional segment is performed, including the placement and guidance of the hole collapse segment, the location and length optimization of the airblast segment, and the design of the charge support structure. S3, charging system design: The three types of functional segments in step S2 are combined and arranged according to the spatial response logic to construct a structural coupling blasting configuration system based on the synergistic effect of the blasting segment, the air blast segment, and the collapse hole segment. This system can achieve active control of the main propagation path of the explosion pressure wave and structural segmented response of the energy release process. S4, detonation system setting and delay setting; S5, blasting implementation.

2. A medium-long hole blasting method with coordinated control of air explosion and hole collapse according to claim 1, characterized in that: In step S2, the collapsed hole section is a natural or artificially constructed non-charged filling body; The layout of the induced collapse hole section is selected in the following three sections: first, the energy transition section between the main blasting section and the protection area; second, the boundary position close to the pillars, tunnels, and rock masses that should not be disturbed; third, the rock mass RQD Low, sudden drilling speed changes during construction, and weak sections with difficult wall protection; The induction strategy for the collapsed hole section is to make the collapsed hole section unstable and collapse in advance before explosion through induction methods, forming a natural non-charged isolation zone; the induction methods include one or a combination of water injection softening induction method, bottom hole explosion disturbance induction method, and light disturbance excitation induction method.

3. The medium-long hole blasting method with coordinated control of air explosion and hole collapse according to claim 1 is characterized in that: In step S2, the air blast section is a non-blasting section in the blast hole where no explosives are loaded; The position of the airblast section is arranged on the main propagation path of the explosion pressure wave, close to the structural protection object but with a predetermined energy dissipation buffer distance. The specific position is calculated according to the following formula: ； in: L ae is the distance from the starting position of the air burst section to the orifice; L is the depth of a single blast hole; D p is the vertical distance from the bottom of the hole to the protective structure; θ is the blasthole inclination angle; δ1 is the structural safety buffer correction, generally 0.4~0.6m; δ2 is the back pressure peak extension correction value, which is set according to the explosion pressure intensity and is taken as 0.3~0.5m; ξ c is the coupling correction value of the collapsed hole section below, which is set to 0.3~0.5m. If there is no collapsed hole section, it is 0; λ g is the correction coefficient for rock mass influence, ranging from 0.1 to 0.5, and is related to the structural surface density and water saturation; R g is the comprehensive structural disturbance index of rock mass, which is composed of joint density, RQD , weighted calculation of surrounding rock grade.

4. A medium-long hole blasting method with coordinated control of air explosion and hole collapse according to claim 3, characterized in that: In step S2, the calculation model for optimizing the airburst length is as follows: ； in: L c is the length of the air burst section, m; E b is the unit explosive energy of the upper blasting section, MJ / m; R t is the explosion pressure path impedance coefficient, which is calculated from the rock density and wave velocity; K v is the rock mass vibration response coefficient, which is comprehensively determined through on-site vibration testing; L cz is the length of the collapsed section below; α, β, and γ are weight and bias factors, and their values are selected according to the on-site structural target fitting: α=0.8, β=0.3, and γ=0.

2.

5. The medium-long hole blasting method with coordinated control of air explosion and hole collapse according to claim 3 is characterized in that: The charge support structure design of the airblast section in step S2 includes: in terms of structural configuration, the airblast section is designed as a non-charge space, with the upper and lower boundaries clearly distinguished from the blasting section or the collapsed hole section, forming an "air cavity isolation zone" with a physical separation effect; low-density disturbance material is optionally filled in the cavity to form a controllable explosion pressure buffer medium.

6. A medium-long hole blasting method with coordinated control of air explosion and hole collapse according to claim 5, characterized in that: The charge support structure design of the air-blast section also includes: in terms of the charge column structure, the air-blast section adopts a whole-tube positioning charge column structure, and the upper and lower charge columns are fixed to the upper and lower edges of the air-blast section through charge tube limiting rings and friction locators to form a stable two-way boundary; the air-blast section is partially hollow and not charged, and a lightweight filling material or an isolation cavity is arranged in the cavity; a hanging anchoring device is arranged at the hole mouth to form an upper support point.

7. The medium-long hole blasting method with coordinated control of air explosion and hole collapse according to claim 5 is characterized in that: The design of the charge support structure of the air-blast section also includes: in terms of charging method, a segmented charging strategy is adopted in the main explosion section above the air-blast section; for areas requiring high control precision, a clamp-controlled bidirectional initiation structure is adopted, and detonator excitation sources are respectively set above and below the air-blast section to construct a clamp-controlled path for the explosion pressure wave.

8. The medium-long hole blasting method with coordinated control of air explosion and hole collapse according to claim 1 is characterized in that: In step S3, the structure-coupled blasting configuration system adopts a "collapse-empty-load-empty-collapse" configuration. The structural design is as follows: the blasting section is located in the middle of the hole, the air blasting sections located above and below the blasting section constitute a directional back pressure zone, and collapsed hole sections are arranged at both ends as peripheral energy absorption belts, and the overall blasting structure three-layer response system of "blasting pressure release core-back pressure buffer layer-disturbance energy absorption belt" is constructed.

9. The medium-long hole blasting method with coordinated control of air explosion and hole collapse according to claim 1, characterized in that: In step S3, the structure-coupled blasting configuration system adopts an "empty-load-collapse" configuration, and the structure is designed as follows: the blasting section is arranged in the middle section of the hole, the lower part is the prone-collapse area or the artificially induced collapse hole section, and the upper part is the air-blast section back pressure control body; Alternatively, the structure-coupled blasting configuration system adopts a "collapse-fill-empty" configuration, and the structural design is: the collapsed hole section is arranged at the bottom of the hole, the upper part is the air blasting section, and the blasting section is embedded in it.

10. The medium-long hole blasting method with coordinated control of air explosion and hole collapse according to claim 1, characterized in that: In step S3, the structure-coupled blasting configuration system adopts an "empty-loaded-empty" configuration. The structure is designed as follows: the blasting section is sandwiched between two air-blasting sections, and the blast pressure is reflected and reflected in a limited space, and then focused multiple times and propagated laterally for release; Alternatively, the structural coupling blasting configuration system adopts "collapse-install-collapse", and the structural design is: the blasting section is sandwiched between the collapse hole sections of the upper and lower natural energy absorption zones, and no air blast section is provided, and the blast pressure is purely attenuated by relying only on the collapse hole section.

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