阅读说明：本技术 一种自然崩落法拉底过坚硬围岩处理方法 (Method for treating over-hard surrounding rock by natural caving method ) 是由 冯兴隆 吴爱祥 李争荣 王贻明 刘明武 曹永� 崔晓东 王少勇 聂胜陆 陈冲 吴 于 2020-10-28 设计创作，主要内容包括：本发明公开了一种自然崩落法拉底过坚硬围岩处理方法,包括：当拉底巷道爆破推进至坚硬围岩区域时,按照扇形中深孔爆破法布置炮孔；在炮孔的同一断面施工多个沿巷道中心线对称分布的静态破碎钻孔；配制静态膨胀剂为糊状,通过高压风将配置的静态膨胀剂压入静态破碎钻孔,直至灌满,不用塞封,静置预设时长；在静置预设时长后,向炮孔内装药；对装药后的炮孔采用排间微差,同排同段起爆的方式进行爆破。本发明可促使围岩节理、裂隙的发育,形成结构弱面。在通过扇形中深孔爆破诱导,实现坚硬围岩的可持续性的冒落。(The invention discloses a method for treating hard surrounding rock by drawing bottom by a natural caving method, which comprises the following steps: when the pull-bottom roadway is blasted and propelled to a hard surrounding rock area, arranging blast holes according to a fan-shaped medium-length hole blasting method; constructing a plurality of static crushing drill holes which are symmetrically distributed along the center line of the roadway on the same section of the blast hole; preparing a static expanding agent into paste, pressing the prepared static expanding agent into a static crushing drill hole through high-pressure air until the static crushing drill hole is filled with the static expanding agent, sealing the static crushing drill hole without using a plug, and standing for a preset time; after standing for a preset time, filling explosive into the blast hole; blasting the blast holes after charging in a mode of row-to-row micro-difference and same-row and same-section initiation. The invention can promote the development of the joints and cracks of the surrounding rock to form a structural weak surface. The sustainable caving of the hard surrounding rock is realized through the induction of the fan-shaped medium-length hole blasting.)

1. A method for treating hard surrounding rock by a natural caving method is characterized by comprising the following steps:

when the pull-bottom roadway is blasted and propelled to a hard surrounding rock area, arranging blast holes according to a fan-shaped medium-length hole blasting method;

constructing a plurality of static crushing drill holes which are symmetrically distributed along the center line of the roadway on the same section of the blast hole;

preparing a static expanding agent into paste, pressing the prepared static expanding agent into the static crushing drill hole through high-pressure air until the static crushing drill hole is filled, and standing for a preset time without plugging;

after standing for a preset time, charging powder into the blast hole;

blasting the blast holes after charging in a mode of row-to-row micro-difference and same-row and same-section initiation.

2. The method for treating the surrounding rock hard by bottom-pulling through the natural caving method according to claim 1, wherein when the blast holes are arranged according to the fan-shaped medium-length hole blasting method, the row spacing is 2.0m, 9 blast holes are arranged in each row, the hole depth is uneven and ranges from 6.30m to 12.50m, the inclination angle of the blast holes is 44-132 degrees, and the diameter of the blast holes is 76 mm.

3. The method for treating hard surrounding rock through bottom-pulling by natural caving according to claim 1, wherein when a plurality of static crushing drill holes symmetrically distributed along the center line of a roadway are constructed on the same section of the blast hole, the number of the static crushing drill holes is 4, the depth of the static crushing drill holes ensures that the vertical top control height is 20.0m, the diameter of the static crushing drill holes is 51mm, and the inclination angles are distributed between 54 degrees and 122 degrees.

4. The method for treating surrounding rock hard by bottom-pulling in natural caving method according to claim 1, wherein the static expanding agent is prepared in paste form, and the static expanding agent is pressed into the static breaking borehole by high pressure wind until the static breaking borehole is filled, and the static breaking borehole is left for a preset time without plugging, comprising:

according to the water and medicament ratio of 1: 3, mixing water and the static expanding agent, stirring the mixture into uniform paste, pressing the paste into the static crushing drill holes through high-pressure air until the static crushing drill holes are filled with the paste, and standing the paste for 8 hours without plugging.

5. The method of treating unconsolidated surrounding rock of claim 1, wherein charging the borehole comprises: pressing the initiating explosive cartridge and the viscous granular ammonium nitrate fuel oil explosive into the bottom and the hole opening of the blast hole by using high-pressure air, and adopting a continuous charging structure; and filling blast holes with stemming, plugging the blast holes with a filler, and arranging the non-charging length of each row of adjacent blast hole orifices in a staggered manner of 2.5m and 3.5m after plugging.

6. The method for treating the surrounding rock hard to bottom by the natural caving method according to claim 1, wherein blasting the loaded blast holes in a mode of row-to-row micro-difference and same-row and same-section detonation comprises the following steps:

detonating at the bottom and the hole mouth of the blast hole by adopting a non-electric detonator, and blasting in multiple rows of subsection differential blasting; the detonator adopts a non-electric millisecond nonel detonator, the connecting line of the detonator and the initiator adopts MS1 section detonators, the first row adopts MS3 section detonators, and the Nth row adopts 2N +1 section detonators; wherein N is a positive integer.

Technical Field

The invention relates to the technical field of mining, in particular to a method for treating hard surrounding rock drawn to the bottom by a natural caving method.

Background

The natural caving method induces the rock mass to naturally fall to form ore blocks under the action of dead weight and ground pressure through cutting of the bottom and the side walls. In engineering practice, however, hard surrounding rock is inevitably encountered, and the surrounding rock has the characteristic of poor collapsibility, so that the continuous development of the collapsibility is influenced. Meanwhile, the ore rock with poor collapsibility is burst collapsed, and air shock waves are easily induced to cause injury accidents of personnel and equipment.

The natural caving bottom-drawing technology is one of the most critical factors influencing the success and failure of the mining method, and unreasonable bottom-drawing technologies can cause the collapse of a bottom roadway, the damage of a bottom structure, stress concentration, air shock waves, poor caving effect, large block rate and the like. At present, the bottom-drawing technology for treating hard surrounding rock by adopting a static blasting method is still in a blank stage.

Disclosure of Invention

The invention provides a method for treating over-hard surrounding rock drawn to the bottom by a natural caving method, which aims to solve the technical problem of poor collapsibility of the over-hard surrounding rock in the bottom drawing process of the natural caving method.

In order to solve the technical problems, the invention provides the following technical scheme:

a method for treating hard surrounding rock drawn by a natural caving method comprises the following steps:

when the pull-bottom roadway is blasted and propelled to a hard surrounding rock area, arranging blast holes according to a fan-shaped medium-length hole blasting method;

constructing a plurality of static crushing drill holes which are symmetrically distributed along the center line of the roadway on the same section of the blast hole;

preparing a static expanding agent into paste, pressing the prepared static expanding agent into the static crushing drill hole through high-pressure air until the static crushing drill hole is filled, and standing for a preset time without plugging;

after standing for a preset time, charging powder into the blast hole;

blasting the blast holes after charging in a mode of row-to-row micro-difference and same-row and same-section initiation.

Further, when the blast holes are arranged according to the fan-shaped medium-length hole blasting method, the row spacing is 2.0m, 9 blast holes are arranged in each row, the hole depths are different and are between 6.30m and 12.50m, the inclination angles of the blast holes are 44-132 degrees, and the diameters of the blast holes are 76 mm.

Further, when a plurality of static crushing drill holes symmetrically distributed along the center line of the roadway are constructed on the same section of the blast hole, the number of the static crushing drill holes is 4, the depth of each static crushing drill hole ensures that the vertical roof control height is 20.0m, the diameter of each static crushing drill hole is 51mm, and the inclination angles are distributed between 54 degrees and 122 degrees.

Further, preparing a static expanding agent into paste, pressing the prepared static expanding agent into the static crushing drill hole through high-pressure air until the static crushing drill hole is filled, and standing for a preset time without plugging, wherein the static expanding agent comprises: according to the water and medicament ratio of 1: 3, mixing water and the static expanding agent, stirring the mixture into uniform paste, pressing the paste into the static crushing drill holes by high-pressure air until the paste is filled, and standing the paste for 8 hours without plugging.

Further, charging into the borehole comprises: pressing the initiating explosive cartridge and the viscous granular ammonium nitrate fuel oil explosive into the bottom and the hole opening of the blast hole by using high-pressure air, and adopting a continuous charging structure; and filling the blast holes with blast mud, plugging the blast holes with fillers, and arranging the non-charging length of each row of adjacent blast hole orifices in a staggered manner of 2.5m and 3.5m after plugging.

Further, blasting the blast holes after charging by adopting a mode of row-to-row micro-difference and same-row and same-section initiation, comprising: detonating at the bottom and the hole mouth of the blast hole by adopting a non-electric detonator, and blasting in multiple rows of subsection differential blasting; the detonator adopts a non-electric millisecond nonel detonator, the connecting line of the detonator and the initiator adopts MS1 section detonators, the first row adopts MS3 section detonators, and the Nth row adopts 2N +1 section detonators; wherein N is a positive integer.

The technical scheme of the invention is suitable for geological working conditions of hard surrounding rock pulled by a natural caving method, in particular to a pulled pipe of the hard surrounding rock pulled by the natural caving method, and the beneficial effects brought by the invention at least comprise:

1. the invention can effectively avoid the situation that the bottom is pulled to pass through the hard surrounding rock and the surrounding rock is over-ridden in a large range;

2. the invention can form sustainable rock mass collapse and avoid the generation of air shock wave;

3. the invention can effectively control the large-scale span and emission of the hard surrounding rock, avoid the generation of stress concentration phenomenon and protect the stability of the bottom structure.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a flowchart of a method for treating hard surrounding rock by a natural caving method according to an embodiment of the present invention;

FIG. 2 is a schematic illustration of a borehole provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of the structure of the viscous granular ammonium oil charge for the fan-shaped medium-length hole blasting in FIG. 2;

FIG. 4 is a schematic view of the static expander charge configuration of FIG. 2;

fig. 5 is a schematic diagram of the connection of the detonation network of fig. 2.

Description of reference numerals:

1. blast holes; 2. statically crushing and drilling; 3. drawing a bottom roadway; 4. a detonator; 5. a granular ammonium nitrate fuel oil explosive;

6. stemming; 7. a tampon; 8. connecting wires; 9. a static swelling agent; 10. an initiator.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to fig. 1 to 5, the present embodiment provides a method for treating hard surrounding rock through bottom-drawing by a natural caving method, which is designed to solve the problem that sustainable free caving of the surrounding rock by self-weight and ground pressure cannot be induced by medium-length hole blasting when a bottom layer of a natural caving method is constructed in a hard surrounding rock area.

The treatment method of the hard surrounding rock pulled from the bottom by the natural caving method firstly weakens the hard rock mass by adopting a static crushing method, and injects a prepared static expanding agent 9 into a preset static crushing borehole 2 to perform static pre-splitting crushing on the rock mass; and then, the viscous granular ammonium nitrate fuel oil explosive 5 is filled into the blast hole 1 by combining a fan-shaped medium-length hole blasting method to carry out bottom blasting, so that the rock mass is induced to realize free caving under the action of dead weight and ground pressure.

Specifically, the execution flow of the method of the present embodiment is shown in fig. 1, and includes the following steps:

s101, when the sublevel 3 is blasted and propelled to a hard surrounding rock area, arranging blast holes 1 according to a conventional fan-shaped medium-length hole blasting method; wherein the row spacing is 2.0m, the number of blast holes 1 in each row is 9, the hole depths are not uniform and are between 6.30m and 12.50m, the inclination angles of the deep holes are distributed at 44 degrees to 132 degrees, and the diameter of the drill hole is 76 mm.

S102, constructing a plurality of static crushing drill holes 2 which are symmetrically distributed along the center line of a roadway on the same section of the blast hole 1; wherein 4 static crushing drill holes 2 are constructed on the same section of the blast hole 1, the depth of each static crushing drill hole 2 ensures that the vertical top control height is 20.0m, the diameter of each drill hole is 51mm, and the dip angle of each deep hole is distributed between 54 degrees and 122 degrees.

S103, preparing a static expanding agent 9 into a paste, pressing the prepared static expanding agent 9 into the static crushing drill hole 2 through high-pressure air until the static crushing drill hole 2 is filled, and standing for a preset time without plugging; wherein, the swelling agent is mixed with water according to the ratio of 1: 3 preparing and stirring the mixture into uniform paste, and standing the paste for 8 hours.

S104, charging powder into the blast hole 1 after standing for a preset time;

specifically, in this embodiment, the steps are specifically as follows:

after the mixture is stopped for about 8 hours, the mixture enters a construction area of a pull-bottom roadway 3, after safety confirmation, a detonator 4 and viscous granular ammonium nitrate fuel oil explosive 5 are pressed into the bottom of a blast hole 1 by high-pressure air, and a continuous charging structure is adopted in the hole opening. The blast holes 1 are filled with stemming 6, then the blast holes 1 are plugged by using a filler 7, and after plugging, the non-charging length of the hole opening of each row of adjacent blast holes 1 is 2.5m and 3.5m in a staggered arrangement.

And S105, blasting the charged blast holes 1 in a mode of row-to-row micro-difference and same-row and same-section detonation.

Specifically, in this embodiment, the steps are specifically as follows:

detonating at the bottom and the orifice of the blast hole 1 by using a non-electric detonator by using a detonator 10, and performing multi-row sectional differential blasting; the detonator 4 adopts a non-electric millisecond nonel detonator, the connecting line 8 of the detonator 4 and the initiator 10 adopts MS1 section detonators, the first row adopts MS3 section detonators, the second row adopts MS5 section detonators, and the like, and the Nth row adopts 2N +1 section detonators; wherein N is a positive integer. Personnel are evacuated during blasting, security guards are made and other safety items to be noted are taken and detonated by the detonator 10 at a prescribed initiation site.

The principle of the method is that the joint and the fracture shearing damage of the hard surrounding rock are induced by combining the fan-shaped medium-length hole blasting and the static expanding agent through a pretreatment technology, and the phenomenon of discontinuous caving of the hard surrounding rock is avoided.

The technical points of the method of the embodiment are as follows:

mechanically drilling holes by using a drilling trolley, wherein the diameter of each viscous granular charge hole is 76mm, the hole spacing is about 2m, and 9 holes are drilled in each row; the diameter of a static crushing drill hole is 51mm, and each row of the drill holes is 4.

The width of the clear section of the pull-bottom roadway is 3.6m and the height is 3.6 m.

The support mode of the pull-bottom roadway mainly adopts a mortar anchor rod, the length of the anchor rod is 2.25m, the diameter of the anchor rod is 22mm, the support mesh degree is 1.0m multiplied by 1.0m, and the surrounding rock is crushed, and the support can also adopt guniting, net hanging and long anchor rope support.

The implementation process of the method of the present embodiment is further described below with reference to specific application examples:

and mining a certain copper ore by a natural caving method. The bottom-pulling roadway is located at the level of 3736m, the specification of the net section of the bottom-pulling roadway is that the width is multiplied by the height by 3.6m multiplied by 3.6m, a rock drilling trolley is adopted to carry out deep hole construction in the bottom-pulling roadway, and the adjustable range of the aperture is 51-89 mm. The bedding zone presents a hard class i rock mass zone. The ore removal statistics work shows that the amount of the caving ore is small, the lumpiness is large, the stress of the bottom structure is concentrated, and the risk of large-range crossing is caused.

For the hard surrounding rock area in the bottom-pulling process, the novel pretreatment technology for passing through hard surrounding rocks by the natural caving method of this embodiment is used, and specific embodiments are described as follows with reference to fig. 2, fig. 3, fig. 4, and fig. 5:

1. pushing the pull-bottom roadway 3 to a hard surrounding rock area, constructing 9 medium-length holes required by the viscous granular ammonium nitrate fuel oil explosive according to the original scheme, wherein the dip angle range of the deep holes is between 44 and 132 degrees, the hole diameter is 76mm, and the drilling depth range is 6.30 to 12.50 m;

2. constructing static crushing drill holes 2 by adopting a simba1354 trolley, wherein 4 drill holes are constructed in each row, the inclination angle range of the drill holes is kept unchanged from 54 degrees to 122 degrees, the hole diameter is 51mm, and the effective height of a top control is 20 m;

3. according to the water and medicament ratio of 1: 3, stirring the static expanding agent 9 into uniform paste, pressing the paste into the static crushing drill hole 2 by using high-pressure air until the paste is filled, and standing for about 8 hours without plugging;

4. after the suspension lasts for about 8 hours, entering a construction area of a pull-bottom roadway 3, and after safety confirmation, pressing an initiating explosive cartridge and viscous granular ammonium nitrate fuel oil explosive into the bottom and the hole opening of the hole by adopting high-pressure air in the fan-shaped medium-length hole;

5. continuous charging structure is adopted, multiple rows of segmental differential blasting are adopted, the detonator 4 adopts a non-electric millisecond detonating tube detonator, the rows are slightly different, and the same row and the same segment are detonated. The connecting wire 8 adopts MS1 sections, the first row adopts MS3 sections of detonators, the second row adopts MS5 sections of detonators, and the like;

6. filling the mixture by using stemming 6, then plugging the blast hole by using a filler 7, and after plugging, arranging the non-charging lengths of the orifices in a staggered manner of 2.5m and 3.5 m;

7. all detonating tubes are bound on the instrument by adopting a row-to-row differential detonating mode and are detonated by the detonator 10.

It should be noted that, in the specific implementation process, when the static expanding agent 9 is poured into the static crushing borehole 2, the static crushing borehole 2 is not sealed until being filled, the borehole is strictly prohibited to be checked within 8 hours of charging, and after 8 hours of charging, the hole can be checked along the edge of the outer hole obliquely under the on-site safety condition with goggles.

Further, it should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

It should be noted that the above describes only a preferred embodiment of the invention and that, although a preferred embodiment of the invention has been described, it will be apparent to those skilled in the art that, once having the benefit of the teachings of the present invention, numerous modifications and adaptations can be made without departing from the principles of the invention and are intended to be within the scope of the invention. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the embodiments of the invention.