阅读说明：本技术 一种露天矿山破碎站基坑控制爆破成型方法 (Controlled blasting forming method for foundation pit of open-pit mine crushing station ) 是由 刘占全 崔凤 徐晓东 闫永富 宋金龙 于 2020-12-29 设计创作，主要内容包括：本发明公开一种露天矿山破碎站基坑控制爆破成型方法,该方法包括基坑开挖设计、穿孔作业设计和爆破作业设计,是一种集三维模拟、降震、减震、精细化控制爆破等多种技术的露天矿山破碎站基坑爆破成型施工方法,可以最大限度的保证基坑壁成型的岩体完整程度,降低基坑的建设成本,降低基坑的后期维护成本,提高破碎机的服务年限和质量。(The invention discloses a pit blasting control molding method for a surface mine crushing station, which comprises the steps of pit excavation design, perforation operation design and blasting operation design, and is a pit blasting molding construction method for the surface mine crushing station, which integrates various technologies such as three-dimensional simulation, shock reduction, shock absorption, fine control blasting and the like, can ensure the integrity of rock mass molded on the wall of a pit to the maximum extent, reduce the construction cost of the pit, reduce the later maintenance cost of the pit, and improve the service life and quality of a crusher.)

1. A method for controlling blasting forming of a foundation pit of a surface mine crushing station comprises the following steps:

A) excavation design of a foundation pit:

(A1) obtaining accurate foundation pit parameter size, accurate lithology of a foundation pit area, geological conditions and field site conditions, and converting a foundation pit model into a visual three-dimensional model by using three-dimensional drawing software;

(A2) according to the lithology of the foundation pit area, proper explosive unit consumption is required, and then blast hole mesh parameters and charge structure indexes are calculated by utilizing the explosive unit consumption;

(A3) designing parameters of an underholing hole, a main blasting hole, a buffer hole and a pre-splitting hole according to the shape of a foundation pit, and designing parameters of a pre-splitting hole corner hole and a half-depth pre-splitting hole of the pre-splitting hole, and parameters of a buffer hole corner hole and a buffer hole half-depth hole of the buffer hole aiming at the intersection line of the foundation pit wall; the pre-splitting holes are positioned on the outermost side, blast holes inwards adjacent to the pre-splitting holes are buffer holes, blast holes inwards adjacent to the buffer holes are main blasting holes, and blast holes inwards adjacent to the main blasting holes are cut holes;

(A4) selecting a proper number of excavation layers according to the parameters of the foundation pit, and determining the boundaries of excavation bodies of all the layers;

(A5) drawing the designed parameters of the blast hole mesh on a visual three-dimensional model, and observing a simulation result to judge whether the spatial position of the blast hole is reasonable;

(A6) carrying out on-site accurate lofting on the blast hole opening positions in the designed blast hole mesh parameters, and accurately lofting the design to the site by utilizing a mode of combined calibration of a positioning system and a steel ruler;

B) and (3) perforation operation design:

(B1) determining the opening positions of a pre-splitting hole, a pre-splitting hole corner hole and a half-deep pre-splitting hole on site according to the design angle of the foundation pit wall, the floor elevation of the site and the position of a designed pre-splitting line, and determining the length and azimuth angle of the blast hole according to the design depth;

(B2) according to the designed positions of the buffer holes, the buffer hole angle holes and the buffer hole half-deep holes, the buffer hole angle holes and the buffer hole half-deep holes are distributed on site, and the length and the azimuth angle of the blast hole are determined according to the site elevation;

(B3) according to the designed main hole blasting position, laying main hole blasting on site, and determining the length and azimuth angle of the blast hole according to the site elevation;

(B4) according to the designed cut hole position, laying cut holes on site, and determining the blast hole length and the blast hole azimuth angle according to the site elevation;

C) blasting operation design:

(C1) during construction, firstly constructing cut holes and main blasting holes, then constructing buffer holes, buffer hole corner holes and buffer half-deep holes, and finally constructing pre-cracked holes, pre-cracked hole corner holes and half-deep pre-cracked holes;

(C2) according to the designed charging mode and charging structure, the charging amount is strictly controlled, and the error of the single-hole charging amount is controlled within +/-1 kg;

(C3) selecting a high-quality qualified digital chip detonator as a detonator of a detonating material, and detonating by adopting a time delay control mode;

(C4) the initiation network adopts a V-shaped initiation network design, wherein the initiation of the pre-splitting hole, the pre-splitting hole corner hole and the semi-deep pre-splitting hole is prior to the initiation of the cut hole, the main blasting hole, the buffer hole corner hole and the semi-deep hole of the cushion hole in the main blasting area;

(C5) the charge structure of the main explosion hole is constructed strictly according to the designed sectional charge amount and interval parameters, and is prohibited from being changed privately on site;

(C6) the pre-splitting explosive column is filled in a combined charging mode of a positioning disc and a PVC (polyvinyl chloride) pipe, so that the pre-splitting explosive column is positioned in the center of the pre-splitting hole and the linear explosive density cannot be changed in the axial direction;

(C7) the pre-splitting explosive column detonating cord and the bus detonating cord are lapped by adopting a T-shaped knot, and a closed loop connecting line is adopted, so that the explosion rejection caused by the discontinuous unidirectional detonating of the detonating cord is avoided;

(C8) the priming detonator adopts a double tube.

Technical Field

The invention belongs to the technical field of mine foundation pit construction, particularly relates to a surface mine crushing station foundation pit blasting control forming method, and particularly relates to a surface mine crushing station foundation pit blasting forming construction method integrating multiple technologies such as three-dimensional simulation, shock reduction, shock absorption, fine control blasting and the like.

Background

The deep mining of the open-pit mine is not economical and reasonable any more by adopting a single automobile or train for transportation along with the deepening of the mining depth, so a semi-continuous production system with a belt transportation system and an automobile transportation system matched with each other is generally used in the deep open-pit mine, and the system has advantages in the aspect of ore and rock transportation cost and can create greater economic benefit for the mine. The construction of a rubber belt transportation system in a mining pit of an open-pit mine requires the construction of a core equipment crushing station of the whole transportation system, and the crushing station also requires the excavation of a crushing station foundation pit in a mining field rock mass and then the placement of a crusher in the foundation pit.

The excavation of the foundation pit is a comprehensive project with high requirements on the construction process, and needs to adopt a refined blasting design and scientific and reasonable excavation management measures. However, the current blasting excavation technology of foundation pits of a crushing station is in the current situation that a kernel person sees the kernel and an intelligence person sees the intelligence, various technical methods are used, but a set of scientific and reasonable comprehensive system method is not formed.

Disclosure of Invention

Aiming at one or more problems in the prior art, the invention provides a method for controlling blasting forming of a foundation pit of a surface mine crushing station, which comprises the following steps:

A) excavation design of a foundation pit:

(A1) obtaining accurate foundation pit parameter size, accurate lithology of a foundation pit area, geological conditions and field site conditions, and converting a foundation pit model into a visual three-dimensional model by using three-dimensional drawing software;

(A2) according to the lithology of the foundation pit area, proper explosive unit consumption is required, and then blast hole mesh parameters and charge structure indexes are calculated by utilizing the explosive unit consumption;

(A3) designing parameters of an underholing hole, a main blasting hole, a buffer hole and a pre-splitting hole according to the shape of a foundation pit, and designing parameters of a pre-splitting hole corner hole and a half-depth pre-splitting hole of the pre-splitting hole, and parameters of a buffer hole corner hole and a buffer hole half-depth hole of the buffer hole aiming at the intersection line of the foundation pit wall; the pre-splitting holes are positioned on the outermost side, blast holes inwards adjacent to the pre-splitting holes are buffer holes, blast holes inwards adjacent to the buffer holes are main blasting holes, and blast holes inwards adjacent to the main blasting holes are cut holes;

(A4) selecting a proper number of excavation layers according to the parameters of the foundation pit, and determining the boundaries of excavation bodies of all the layers;

(A5) drawing the designed parameters of the blast hole mesh on a visual three-dimensional model, and observing a simulation result to judge whether the spatial position of the blast hole is reasonable;

(A6) carrying out on-site accurate lofting on the blast hole opening positions in the designed blast hole mesh parameters, and accurately lofting the design to the site by utilizing a mode of combined calibration of a positioning system and a steel ruler;

B) design of punching operation

(B1) Determining the opening positions of a pre-splitting hole, a pre-splitting hole corner hole and a half-deep pre-splitting hole on site according to the design angle of the foundation pit wall, the floor elevation of the site and the position of a designed pre-splitting line, and determining the length and azimuth angle of the blast hole according to the design depth;

(B2) according to the designed positions of the buffer holes, the buffer hole angle holes and the buffer hole half-deep holes, the buffer hole angle holes and the buffer hole half-deep holes are distributed on site, and the length and the azimuth angle of the blast hole are determined according to the site elevation;

(B3) according to the designed main hole blasting position, laying main hole blasting on site, and determining the length and azimuth angle of the blast hole according to the site elevation;

(B4) according to the designed cut hole position, laying cut holes on site, and determining the blast hole length and the blast hole azimuth angle according to the site elevation;

C) blasting operation design

(C1) During construction, firstly constructing cut holes and main blasting holes, then constructing buffer holes, buffer hole corner holes and buffer half-deep holes, and finally constructing pre-cracked holes, pre-cracked hole corner holes and half-deep pre-cracked holes;

(C2) according to the designed charging mode and charging structure, the charging amount is strictly controlled, and the error of the single-hole charging amount is controlled within +/-1 kg;

(C3) selecting a high-quality qualified digital chip detonator as a detonator of a detonating material, and detonating by adopting a time delay control mode;

(C4) the initiation network adopts a V-shaped initiation network design, wherein the initiation of the pre-splitting hole, the pre-splitting hole corner hole and the semi-deep pre-splitting hole is prior to the initiation of the cut hole, the main blasting hole, the buffer hole corner hole and the semi-deep hole of the cushion hole in the main blasting area;

(C5) the charge structure of the main explosion hole is constructed strictly according to the designed sectional charge amount and interval parameters, and is prohibited from being changed privately on site;

(C6) the pre-splitting explosive column is filled in a combined charging mode of a positioning disc and a PVC (polyvinyl chloride) pipe, so that the pre-splitting explosive column is positioned in the center of the pre-splitting hole and the linear explosive density cannot be changed in the axial direction;

(C7) the pre-splitting explosive column detonating cord and the bus detonating cord are lapped by adopting a T-shaped knot, and a closed loop connecting line is adopted, so that the explosion rejection caused by the discontinuous unidirectional detonating of the detonating cord is avoided;

(C8) the priming detonator adopts a double tube.

The open mine crushing station foundation pit blasting forming construction method provided by the invention based on the technical scheme is an open mine crushing station foundation pit blasting forming construction method integrating multiple technologies such as three-dimensional simulation, shock reduction, shock absorption, fine control blasting and the like, can ensure the integrity degree of a rock mass formed on the wall of the foundation pit to the maximum extent, reduces the construction cost of the foundation pit, reduces the later maintenance cost of the foundation pit, and improves the service life and quality of a crusher. Therefore, the problems of unreasonable design, low blasting safety, poor earthquake reduction and damping technology, low excavation efficiency and the like in the existing blasting construction of the foundation pit of the crushing station can be effectively solved.

Drawings

FIG. 1 is a schematic diagram of key information of foundation pit excavation design;

FIG. 2 is a schematic diagram of arrangement of blast holes of a foundation pit;

FIG. 3 is a schematic diagram showing the relationship between pre-split holes and pre-split surfaces;

FIG. 4 is a schematic diagram of the spatial position relationship of pre-splitting holes;

FIG. 5 is a schematic diagram of the spatial position relationship of the auxiliary holes;

FIG. 6 is a schematic view of the spatial positions of main blasting holes and cut holes;

FIG. 7 is a schematic diagram of the arrangement position of blast holes;

FIG. 8 is a schematic view of the design of the detonating circuit;

FIG. 9 is a schematic view of a pre-split charge structure;

the reference numerals are represented as:

1-rock mass around a foundation pit, 2-foundation pit excavation body, 3-first layer excavation body, 4-second layer excavation body, 5-cut hole, 6-main blasting hole, 7-buffer hole, 8-pre-splitting hole, 9-first layer excavation body boundary, 10-pre-splitting line, 11-half-depth pre-splitting hole, 12-pre-splitting hole corner hole, 13-pit wall intersection line, 14-buffer hole corner hole, 15-buffer hole half-deep hole, 16-detonating cord, 17-blast hole delay, 18-pre-splitting hole wall, 19-pre-splitting explosive column, 20-PVC pipe and 21-positioning disc.

Detailed Description

The invention aims to provide a method for controlling blasting and forming of a foundation pit of a crushing station of a surface mine, which can solve the problems of unreasonable design, low blasting safety, poor earthquake reduction and damping technology, low mining efficiency and the like in the blasting construction of the foundation pit of the crushing station at present and has the advantages of strong operability, high construction efficiency and guaranteed construction quality.

The method for controlling blasting and forming the foundation pit of the open-pit mine crushing station provided by the invention is specifically explained in the following by combining the attached drawings.

A method for controlling blasting forming of a foundation pit of a surface mine crushing station comprises the following steps:

firstly, accurate foundation pit parameter size, accurate lithology of a foundation pit area, geological conditions and site situation are obtained. And then designing a foundation pit excavation scheme according to the designed parameters and the actual parameters on site. The design content mainly comprises an excavation sequence and a blasting mode. The foundation pit model is converted into a visual three-dimensional model by utilizing three-dimensional mapping software such as CAD (computer-aided design), Solideworks and the like, the design is carried out on the basis of the model, the simulation demonstration can well reflect that no calculation is accurate or comprehensive flaws are considered in the design, the design is further optimized and adjusted, the simulation of mesh design, excavation structure and the like can be realized, and the defects in the theoretical design and the theoretical calculation process can be overcome by observing the condition of the model. Since the foundation pit blasting belongs to a refined controlled blasting technology, and has special requirements besides the same embodiment as the conventional blasting, specific contents are listed in the following specific embodiments.

The foundation pit excavation scheme is designed and implemented:

the first step is as follows: according to lithology and other influence factors of an explosion area, proper explosive unit consumption is required, key indexes such as pore network parameters and charge structures are calculated by using the explosive unit consumption, as shown in fig. 1, a key information schematic diagram of foundation pit excavation design is shown, wherein key information required by the foundation pit excavation design comprises a foundation pit peripheral rock mass 1, a foundation pit excavation body 2, a first layer excavation body 3, a second layer excavation body 4, an undermined hole 5, a main blasting hole 6, a buffer hole 7, a pre-cracked hole 8, a first layer excavation body boundary 9 and a second layer excavation body boundary 9, and fig. 2 shows a layout schematic diagram of the undermined hole 5, the main blasting hole 6, the buffer hole 7 and the pre-cracked hole 8 of a foundation pit blast hole; the full-explosion area adopts inclined blast holes, the inclination angle of the blast holes is mainly bidirectional inclined, and uniform resistance lines can be formed in the directions of a free surface and a pre-fracture surface; because the foundation pit blasting belongs to blasting operation under the condition of limited space, and the foundation pit is usually a body to be blasted with a regular shape, square blast holes are generally adopted for balancing the single area of the holes, so that the aim of balancing the parameters of the hole network is fulfilled;

the second step is that: as shown in fig. 3 and 4, the parameters of the pre-cracked holes 8 and the buffer holes 7 are designed according to the shape of the foundation pit, particularly the pre-cracked holes 8 and the buffer holes 7 located at the intersection line 13 of the foundation pit wall, and the hole mesh parameters of the pre-cracked holes 8 and the buffer holes 7 in the area need to be specially adjusted; specifically, a pre-splitting hole corner hole 12 and a half-deep pre-splitting hole 11 which are used as supplements of the pre-splitting hole 8 are drilled at the intersection line 13 of the foundation pit wall according to the designed wall included angle space position, and the depths of the pre-splitting hole corner hole 12 and the half-deep pre-splitting hole 11 are specially designed according to the wall included angle, so that the designed pre-splitting hole 8 forms a set pre-splitting molding space shape in the area; in addition, as shown in fig. 5, a buffer hole angle hole 14 and a buffer hole semi-deep hole 15 are also designed on two sides of the buffer hole 7 at the pit wall intersection line 13, and the depths of the buffer hole angle hole 14 and the buffer hole semi-deep hole 15 are specially designed according to the wall included angle; as shown in fig. 2 and 6, inside the buffer holes 7 are the main explosion holes 6 and the cut holes 5. As shown in fig. 7, the pre-split holes 8, the pre-split hole corner holes 12 and the half-deep pre-split holes 11 on the outer side adopt smaller hole pitches, the hole depths are accurately calculated, and the blasting control molding is performed by adopting the principle of non-coupling blasting of small hole pitches and large wire loading densities; the buffer holes 7, the buffer hole corner holes 14, the buffer hole semi-deep holes 15, the main blasting holes 6 and the cut holes 5 on the inner side adopt a large-interval non-coupling charging blasting technology according to the principle of reducing the linear charging density, so that the designed blasting area forms a set pre-splitting forming space shape in the area;

the third step: as shown in fig. 1, according to the parameters of the foundation pit, selecting a proper number of excavation layers (two layers in this embodiment), determining a boundary 9 between the first layer excavation body and the second layer excavation body, and using the spatial position of the boundary as the interface between the first layer excavation body 3 and the second layer excavation body 4; the crushing station foundation pit of a common surface mine is an inverted frustum space with a large depth, a presplitting one-step forming and upper-lower layering mining mode is generally adopted in consideration of blasting vibration and integrity of a foundation pit wall, and when the foundation pit with a large upper opening is encountered, horizontal zoning blasting can be carried out on the same layering on the basis of upper-lower layering. However, in order to reduce the influence of blasting vibration on the final pit wall, the blasting frequency should be reduced as much as possible, the blasting of the next layer should be performed by properly increasing the blasting delay time interval of blast holes, properly reducing the unit consumption of explosive, and performing loose blasting as much as possible;

the fourth step: drawing the designed blast hole parameters on a three-dimensional model, and observing a simulation result to judge whether the spatial position of the blast hole is reasonable. Whether the existing hole pattern parameters completely cover the foundation pit excavation body 2 or not;

the fifth step: and carrying out on-site accurate lofting on the designed hole opening position of the blast hole, and accurately lofting the design to the site by utilizing a mode of joint verification of a positioning system (such as a GPS) and a steel ruler.

The specific implementation mode of the perforation operation is as follows:

the first step is as follows: according to the design angle of the foundation pit wall, the floor elevation of the site and the position of the design pre-splitting line 10, determining the opening positions of a pre-splitting hole angle hole 12 and a half-depth pre-splitting hole 11 at the intersection line 13 of the pre-splitting hole 8 and the foundation pit wall on site, and determining the blast hole length and the blast hole azimuth angle according to the design depth; a high-precision measuring instrument and drilling machine equipment with excellent equipment state are utilized, a fine perforation organization is adopted near a pre-splitting line 10, a positioning hole of a standard hole position is drilled, then a limiting rod is arranged in the positioning hole, and the limiting rod is in rigid positioning connection with a drill rod of a drilling machine with pre-splitting holes 8, pre-splitting hole corner holes 12 and half-deep pre-splitting holes 11 to be drilled, so that strict positioning of perforation is realized. Before each pre-split hole 8, the pre-split hole angle hole 12 and the half-depth pre-split hole 11 are drilled, during drilling and after rod replacement, three times of drill rod inclination angle verification is carried out, and the drill rod is adjusted in time when deviation is found;

the second step is that: according to the positions of the designed buffer hole 7, buffer hole angle hole 14 and buffer punched hole semi-deep hole 15, the buffer hole 7, the buffer hole angle hole 14 and the buffer punched hole semi-deep hole 15 are distributed on site, and the blast hole length and the blast hole azimuth angle are determined according to the site elevation;

the third step: according to the designed position of the main blast hole 6, the main blast hole 6 is distributed on site, and the length and the azimuth angle of the blast hole are determined according to the site elevation;

the fourth step: according to the position of the designed cut hole 5, laying the cut hole 5 on site, and determining the length and the azimuth angle of the blast hole according to the site elevation;

the fifth step: before each hole is opened, whether the hole opening position and the hole opening direction are correct or not is strictly checked, the verification is carried out once again when one drill rod is replaced, and the hole opening angle is properly adjusted according to the deviation condition of a drill bit if necessary;

and a sixth step: the 'one-hole one-test' is strictly carried out, the qualified test is carried out after one hole is drilled every time, and a protective cushion is required to cover after the acceptance is qualified, so that the blast hole is prevented from being damaged.

The specific implementation mode of the blasting operation is as follows:

the first step is as follows: rechecking the explosion pre-design scheme, and if the design needs to be changed due to lithology, construction and the like on site, performing design adjustment in time;

the second step is that: during construction, firstly constructing cut holes 5 and main blasting holes 6, then constructing buffer holes 7, buffer hole corner holes 14 and buffer hole semi-deep holes 15, and finally constructing pre-cracked holes 8, pre-cracked hole corner holes 12 and semi-deep pre-cracked holes 11;

the third step: the loading capacity is strictly controlled according to the designed loading mode and loading structure, and the error of the loading capacity of a single hole is controlled within +/-1 kg because the foundation pit controlled blasting belongs to refined blasting; the diameter of the pre-splitting grain is used as a reference for the pre-splitting hole, and pre-splitting blasting is facilitated when the non-coupling coefficient is more than 2.5; the buffer hole and the main blast hole select blast holes with small apertures as much as possible under the condition of considering the convenience of charging; the cut hole can properly select a blast hole with a slightly larger aperture, more explosives can be loaded, and larger free space is formed in the blasting process; the explosive charge of the main blast hole is less, the length of the whole explosive column is limited, and the distribution of the explosive energy of the whole blast hole can be influenced by centralized explosive charge, so that the distribution condition of the explosive energy in the blast hole can be improved by adopting an interval explosive charge mode;

the fourth step: the detonator of the initiating equipment should adopt a high-quality qualified digital chip detonator, and the digital chip detonator has higher delay precision, so that more reasonable delay control can be realized; the advantage that the detonation time interval of the digital chip detonator can be manually adjusted is utilized, and reasonable delay time interval setting can be selected according to the principle that the inter-hole interval is lower than the inter-row interval under the condition that the hole network parameters of blast holes are considered;

the fifth step: the initiation network should adopt a V-shaped initiation network design, which is suitable for the limited area of the free surface and can reduce the extrusion damage to the foundation pit wall; as the foundation pit blasting belongs to blasting with large blasting clamping performance, the blasting free surface is not sufficient, and the space compensation is not sufficient during rock blasting, the network design adopting the V-shaped blasting mode is more favorable for forward throwing of the blasting rock, improving the overall looseness of the blasting pile and avoiding excessive extrusion damage to the pre-splitting surface, as shown in figure 8, a V-shaped blasting network design schematic diagram is shown according to the blasting time, so that the pre-splitting hole is blasted before a main blasting area (an undermined hole, a main blasting hole, a buffer hole corner hole and a buffer punched semi-deep hole) and is blasted in three-side pre-splitting holes at three interval time periods, the operation can avoid tight pulling of a blasting cord at a right-angle joint and can control simultaneous blasting and blasting vibration interference between the pre-splitting holes; in the main explosion area, initiating explosion is started from the cut hole at one side without the pre-cracked hole, and the initiation is gradually delayed towards the blast hole in the main explosion area by a V-shaped network;

and a sixth step: the charge structure of the main explosion hole is constructed strictly according to the designed sectional charge amount and interval parameters, and is prohibited from being changed privately on site;

the seventh step: as shown in fig. 9, the pre-split charge column 19 is loaded by adopting a combined charging mode of a positioning plate 21 and a PVC pipe 20, etc., so that the pre-split charge column 19 is positioned at the center of the pre-split hole and the linear charge density is not changed in the axial direction; because the pre-splitting hole is an inclined blast hole, the conventional auxiliary devices such as bamboo chips and the like are difficult to enable the pre-splitting explosive column to be positioned in the center of the pre-splitting hole, so that the explosive is often tightly attached to one side of the hole wall in the hole, and the situation of low half-wall porosity is caused. Therefore, the positioning disc and the high-strength PVC pipe are used, the presplitting explosive columns are bound on the detonating cord according to the designed spacing distance and are accurately distributed by the high-strength PVC pipe, and then the explosive columns bound with the PVC pipe are arranged in the middle of the presplitting hole by the positioning disc, so that the presplitting explosive columns are accurately positioned in the presplitting hole; the presplitting explosive columns are filled at the bottom in a reinforced mode, continuous interval charging is carried out at the middle of the presplitting explosive columns, the presplitting explosive columns are uniformly distributed in the blast holes, and the line charge density in the interval can be properly adjusted for the blast holes with non-uniform lithology; the top of the explosive column is filled with weakened explosive, and the interval length of the explosive column is adjusted to be 1.5 times of the interval length of the middle normal section;

eighth step: the pre-splitting explosive column detonating cord and the bus detonating cord are lapped by adopting a T-shaped knot, and a closed loop connecting line is adopted, so that the explosion rejection caused by the discontinuous unidirectional detonating of the detonating cord is avoided; the conventional detonating cord is one-way detonating, and is strictly transmitted from one end of the detonating cord to the other end of the detonating cord to detonate the detonating cord for binding the presplitting explosive column along the way, so that the full-section detonating in the hole of the presplitting hole is realized. But if a bus at a certain position in the detonating cord explosion propagation process is subjected to explosion rejection, the downstream point to be exploded of the explosion rejection point is subjected to explosion rejection. Therefore, in order to improve the detonation reliability of the presplitting blasting, the two-way detonation of the detonating cord is realized by adopting a detonating cord closed-loop connection detonating mode and utilizing the T-shaped knot, and even if the forward detonation fails, the detonating cord can be detonated when the reverse detonation reaches the explosion-rejecting point again, which is equivalent to double insurance of a detonating network of the presplitting explosive columns;

the ninth step: generally, for the fine blasting, the detonating detonator adopts double tubes, so that the quality of detonating detonator booster blasting is guaranteed.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.