Deep yielding exploiting method for steeply inclined ore body

Abstract

The invention discloses a deep yielding development method for a steeply inclined ore body, which relates to the technical field of mining engineering and comprises the following steps of: determining a damage range of hanging wall wedge-shaped body pressure to development engineering in a preparation stage; according to the damage range of the pressure of the wedge-shaped body, the pressure damage angle of the wedge-shaped body is determined, a pressure bearing area and a yielding area are divided in the yielding development stage, and the hanging wall along-vein haulage roadway is arranged in the yielding area; determining a draw shaft inclination angle; determining the position of an upper opening of the draw shaft; determining the lower opening position of the draw shaft according to the upper opening position of the draw shaft and the determined dip angle of the draw shaft; the reasonable length of the transverse drift roadway capable of meeting the production requirement is determined; determining the position of a footwall along-vein haulage roadway according to the determined position of the footwall along-vein haulage roadway, the reasonable length of the transverse drift roadway and the position of a drop shaft lower opening; according to the method, the deep development system of the steeply inclined ore body can avoid the pressure effect of the hanging wall wedge-shaped body, the service life of development engineering is prolonged, the annular transportation function of the development system can be guaranteed, and normal production of a mine is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of mining engineering, in particular to a deep pressure-releasing development method for a steeply inclined ore body. Background Art

[0002] In the underground mining of steeply inclined ore bodies of metal mines, a circular transportation method is usually adopted, and a planar circular transportation system is formed by the upper and lower plate vein transportation tunnels and the through-vein tunnels. When the mining depth reaches a certain depth, the vein transportation tunnels arranged in the surrounding rock of the upper plate (referred to as the upper plate vein transportation tunnels) are exposed to the pressure of the wedge-shaped body of the upper plate, and the degree of the wedge-shaped ground pressure continues to increase with the increase of mining depth. The deep ground pressure is intense, and the tunnel excavation and maintenance are very difficult, which seriously affects the normal production and operation of the mine.

[0003] In order to reduce the damage of the wedge-shaped ground pressure to the upper plate development project, high-strength support methods are mainly used on site during tunnel excavation, including sprayed anchor net + metal arch frame, reinforced concrete masonry and other support forms. After 2 to 3 years of use, under the huge wedge-shaped pressure, the upper plate along the vein transportation tunnel and the vein-crossing tunnel close to the upper plate side are gradually damaged and cannot be used. During maintenance, it is necessary to remove the metal arch frame and concrete support layer, clean the broken surrounding rock on the arch and both sides, remove the bottom drum, and re-carry out high-strength support. However, many parts still continue to deform and damage under the action of the wedge-shaped ground pressure after secondary support, requiring multiple repairs, which are difficult to repair. Some tunnels are severely damaged after 1 to 2 repairs and cannot be used, which seriously affects the safe production and operation of the mine. For this reason, it is urgent to study a pressure-releasing development method that can not only make the development project give way to the effect of the upper plate wedge pressure, but also ensure the circular transportation needs. Summary of the invention

[0004] The purpose of the present invention is to provide a method for deep pressure-releasing development of a steeply inclined ore body, which allows the development project to avoid the huge pressure effect of the upper plate wedge during deep development of the steeply inclined ore body to ensure the circular transportation demand.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a method for deep pressure relief development of a steeply inclined ore body, comprising the following steps:

[0007] Step S1, using field investigation, theoretical research, laboratory experiments, and numerical simulation methods to determine the damage range of the pressure of the upper plate wedge to the development project in the preparation stage, and determining the pressure damage angle of the upper plate wedge according to the damage range of the development project in the preparation stage and the position relationship of the empty area in the mining stage;

[0008] Step S2, dividing the pressure-bearing area and the pressure-yielding area according to the pressure failure angle, arranging the upper wall along-vein transport lane in the pressure-yielding area to avoid the pressure effect of the upper wall wedge-shaped body;

[0009] Step S3, determining the length of the through-the-vein roadway according to the position of the upper plate along-the-vein transport roadway, the loading length of the straight section of the through-the-vein roadway, the radius of curvature at the intersection of the through-the-vein roadway and the upper plate along-the-vein transport roadway, the radius of curvature at the intersection of the through-the-vein roadway and the lower plate along-the-vein transport roadway, and the position of the chute;

[0010] Step S4, determining the inclination of the chute according to the relationship between the pressure failure angle and the inclination of the upper wall of the ore body;

[0011] Step S5, determining the upper opening position of the chute according to the number of sections in the preparation stage and the ore-exporting demand of the lowest section, combined with the ore-exporting demand of each section in the pressure-releasing development stage;

[0012] Step S6, determining the lower opening position of the chute according to the inclination angle of the chute in step S4 and the upper opening position of the chute in step S5;

[0013] Step S7, determining the position of the lower wall along-vein transport tunnel according to the length of the vein-penetrating tunnel described in step S3 and the lower opening position of the chute described in step S6.

[0014] Preferably, the determination of the pressure failure angle comprises the following steps:

[0015] Step A, on-site investigation: based on the damage of the hanging wall engineering revealed on-site, preliminarily determine the pressure action range of the hanging wall wedge, divide the pressure-bearing area and the pressure-yielding area, and provide on-site basis for the numerical simulation of the pressure of the hanging wall wedge;

[0016] Step B, determination of rock mass mechanical parameters: through field sampling and laboratory testing, the physical and mechanical parameters of the rock mass are obtained to provide a theoretical basis for numerical simulation;

[0017] Step C, establishing a numerical simulation model: based on the occurrence and physical and mechanical parameters of the actual rock mass and the actual mining conditions, a geometric model of the ore body and the surrounding rock of the upper wall and the surrounding rock of the lower wall is established;

[0018] Step D, numerical simulation analysis: performing numerical simulation analysis on the model to determine the pressure damage range and impact range of the upper wall wedge during mining at each stage;

[0019] Step E, determination of the pressure failure angle: referring to the damage of the upper plate project revealed on site and combining the results of numerical simulation, determine the damage boundary of the pressure of the upper plate wedge on the upper plate surrounding rock, connect the damage boundary point of the pressure of the upper plate wedge on the upper plate surrounding rock with the upper plate boundary point of the upper mining stage, and the angle between the line segment formed by connecting the boundary point of the damage zone with the boundary point of the upper plate in the upper mining stage and the horizontal line is the pressure failure angle.

[0020] Preferably, in step S1, the boundary point of the destruction zone and the boundary point of the upper plate are connected, and the angle between the line segment formed by connecting the boundary point of the destruction zone and the boundary point of the upper plate and the horizontal line that is less than 90° is the pressure destruction angle, the upper plate side of the pressure destruction angle is the pressure-bearing zone, and the lower plate side of the pressure destruction angle is the pressure-yielding zone.

[0021] Preferably, the pressure failure range of the upper plate wedge extends from top to bottom along the inclination of the ore body, and the pressure failure angle is 75° to 90°.

[0022] Preferably, when the inclination angle of the upper plate of the ore body is not less than the pressure failure angle, the inclination angle of the chute adopts the inclination angle of the upper plate of the ore body; when the inclination angle of the upper plate of the ore body is less than the pressure failure angle, the inclination angle of the chute adopts the pressure failure angle.

[0023] Preferably, the pressure failure angle is determined first, and based on the pressure failure angle, the pressure-bearing zone and the pressure-yielding zone are delineated. Secondly, the position of the upper plate along-vein transport tunnel is determined within the pressure-yielding zone. Then, the length of the through-vein tunnel is determined. Then, the inclination angle of the chute, the position of the upper opening of the chute and the position of the lower opening of the chute are determined. Finally, the position of the lower plate along-vein transport tunnel is determined. While avoiding the pressure effect of the upper plate wedge, normal circular transportation of the upper plate along-vein transport tunnel, the through-vein tunnel, the lower plate along-vein transport tunnel and the chute is ensured.

[0024] Compared with the prior art, the present invention has achieved the following technical effects:

[0025] The invention determines the pressure failure angle of the upper plate wedge according to the pressure failure range of the upper plate wedge, divides the pressure-bearing area and the pressure-yielding area, and arranges the upper plate along-vein transport lane in the pressure-yielding area, thereby avoiding the upper plate along-vein transport lane and the through-vein lane being directly subjected to the pressure of the upper plate wedge, reducing the effect of the upper plate wedge pressure on the lower plate along-vein transport lane and the chute through the goaf, improving the stability of the upper plate along-vein transport lane, the through-vein lane, the lower plate along-vein transport lane and the chute, and extending the service life of the development project;

[0026] The method for determining the inclination angle of the chute according to the relationship between the inclination angle of the upper plate of the ore body and the pressure failure angle of the upper plate wedge in the present invention can reduce the effect of the pressure of the upper plate wedge on the chute through the loose body in the goaf, improve the stability of the chute, and increase the service life of the chute. At the same time, the method can flexibly arrange the chute according to the manifestation law of the ground pressure of the upper plate wedge, and give full play to the maximum advantage of the chute in circular transportation.

[0027] In the present invention, the upper plate along-vein transport lane, the through-vein lane, the lower plate along-vein transport lane and the chute form a complete circular transport system in the ore body, satisfying the circular transport function in the ore body;

[0028] In summary, the present invention not only avoids the damage of the upper plate wedge-shaped body ground pressure to the development tunnel and the chute through the above method, but also ensures the normal function of the circular transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 This is a schematic diagram of the pressure relief development method for steeply inclined ore bodies;

[0031] Figure 2 It is a wedge-shaped model;

[0032] Figure 3 Make up a model for the wedge-shaped body;

[0033] Figure 4 It is the wedge-shaped model when y = π, β = π / 2;

[0034] Figure 5 It is the geological profile of the exploration line;

[0035] Figure 6 It is the geometric dimensions of the ore body model and the distribution map of measuring points;

[0036] Figure 7 It is the ore body model calculated by the software DDA;

[0037] Among them, 1. Vein-carrying tunnels in the upper plate during the yielding and development stage; 2. Vein-penetrating tunnels in the yielding and development stage; 3. Vein-carrying tunnels in the lower plate during the yielding and development stage; 4. Shafts in the yielding and development stage; 5. Vein-carrying tunnels in the upper plate during the preparation stage; 6. Vein-penetrating tunnels in the preparation stage; 7. Vein-carrying tunnels in the lower plate during the preparation stage; 8. Segmented cutting tunnels in the preparation stage; 9. Segmented connecting tunnels in the preparation stage; 10. Segmented mining approaches in the preparation stage; 11. Vein-carrying tunnels in the lower plate during the preparation stage; 12. Shafts in the preparation stage; 13. Mining blastholes; 14. Vein-carrying tunnels in the upper plate during the mining stage; 15. Vein-penetrating tunnels in the mining stage; 16. Vein-carrying tunnels in the lower plate during the mining stage; 17. Loose ore; 18. Loose goaf; 19. Boundary between the pressure-bearing zone and the yielding zone of the wedge; 20. Upper plate of the ore body; 21. Lower plate of the ore body. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] It should be noted that in this paper, the upper plate vein transport lane 1 in the yielding development stage, the upper plate vein transport lane 5 in the preparation stage, and the upper plate vein transport lane 14 in the mining stage are the states of the upper plate vein transport lane in the yielding development stage, the preparation stage, and the mining stage respectively. The upper plate vein transport lane 1 in the yielding development stage is the basic skeleton of the upper plate vein transport lane, and the basic lane layout of the upper plate vein transport lane is carried out in this stage; the upper plate vein transport lane 5 in the preparation stage is refined and expanded on the basis of the upper plate vein transport lane 1 in the yielding development stage; the upper plate vein transport lane 14 in the mining stage forms the final mining system, namely the upper plate vein transport lane, on the basis of the upper plate vein transport lane 1 in the yielding development stage and the upper plate vein transport lane 5 in the preparation stage, and uses the upper plate vein transport lane to transport ore.

[0041] In this paper, the vein tunnel 2 in the pressure-releasing development stage, the vein tunnel 6 in the preparation stage, and the vein tunnel 15 in the mining stage are respectively the states of the vein tunnels in the pressure-releasing development stage, the preparation stage, and the mining stage. The through-vein tunnel 2 in the yielding and development stage serves the initial development project of the mining area, connects the upper wall 20 of the ore body and the lower wall 21 of the ore body, provides a preliminary layout for the mining area development, and provides a basic framework for the through-vein tunnel 6 in the preparation stage and the through-vein tunnel 15 in the recovery stage; the through-vein tunnel 6 in the preparation stage refines and improves the tunnel network of the mining area on the basis of the through-vein tunnel 2 in the yielding and development stage, lays the foundation for the through-vein tunnel 15 in the recovery stage, and is used for ore body zoning, recovery block segmentation, installation of equipment or pipelines, etc., which not only provides support for recovery, but also can undertake part of the transportation tasks in the initial stage, but the intensity and scale are smaller than those in the recovery stage; the through-vein tunnel 15 in the recovery stage makes full use of the tunnel network of the through-vein tunnel 2 in the yielding and development stage and the through-vein tunnel 6 in the preparation stage, integrates and optimizes them, supports actual recovery operations, and provides direct services for core tasks such as ore transportation, ventilation and smoke exhaust, and equipment maintenance.

[0042] In this paper, the footwall along-vein transport lane 3 in the yielding and development stage, the footwall along-vein transport lane 7 in the preparation stage, and the footwall along-vein transport lane 16 in the mining stage are the states of the footwall along-vein transport lane at different stages. The footwall along-vein transport lane 3 in the yielding and development stage provides the basic transportation function in the early stage of mining area development, and provides support for the subsequent preparation stage and mining stage; the footwall along-vein transport lane 7 in the preparation stage is further refined on the basis of the footwall along-vein transport lane 3 in the yielding and development stage, so that the footwall along-vein transport lane can support the zoning operation and equipment layout of specific ore blocks; the footwall along-vein transport lane 16 in the mining stage is based on the footwall along-vein transport lane 7 in the preparation stage, and carries the actual production and transportation tasks, which is the core of the entire footwall along-vein transport system. The footwall along-vein transport lane 3 in the yielding and development stage is roughly located, providing basic connectivity; the footwall along-vein transport lane 7 in the preparation stage is closer to the ore body and combined with the mining needs; the footwall along-vein transport lane 16 in the mining stage is finally arranged around the actual mining area.

[0043] In this article, the pressure-release development stage chute 4 and the preparation stage chute 12 are stages of the chutes at different times. The pressure-release development stage chute 4 is a vertical transportation channel developed in the early stage of the mining area, providing basic services for the development project, mainly meeting the needs of early tunnel excavation and development waste rock transportation. The preparation stage chute 12 optimizes the layout and functions on the basis of the pressure-release development stage chute 4, serves the zoning preparation of specific mining blocks, and supports the production needs of the subsequent mining stage by expanding and transforming the pressure-release development stage chute 4 and upgrading the transportation function.

[0044] like Figure 1 The present invention discloses a method for deep pressure relief development of a steeply inclined ore body, comprising the following steps:

[0045] Step S1, using methods such as field investigation, theoretical research, laboratory experiments, and numerical simulation, determine the damage range of the pressure of the upper plate wedge to the development project in the preparation stage, and determine the pressure damage angle β of the upper plate wedge according to the relationship between the damage range of the development project in the preparation stage and the position of the empty area in the mining stage;

[0046] Step S2, dividing the pressure-bearing area and the pressure-yielding area according to the determined pressure failure angle β of the hanging wall wedge, arranging the hanging wall along-vein transport lane in the pressure-yielding area to avoid the pressure effect of the hanging wall wedge;

[0047] Step S3, according to the determined position of the upper plate along-vein transport laneway, taking into account the loading length of the straight section of the through-vein laneway, the radius of curvature at the intersection with the upper plate along-vein transport laneway and the lower plate along-vein transport laneway, and the position of the chute opening, determine a reasonable length of the through-vein laneway;

[0048] Step S4, determining the inclination angle of the chute according to the relationship between the pressure failure angle β of the upper wall wedge and the inclination angle α of the upper wall of the ore body;

[0049] Step S5, determining the upper opening position of the chute according to the number of sections in the preparation stage and the ore-exporting demand of the lowest section, combined with the ore-exporting demand of each section in the pressure-releasing development stage;

[0050] Step S6, determining the lower opening position of the chute according to the chute inclination angle determined in step S4 and the upper opening position of the chute determined in step S5;

[0051] Step S7, determining the position of the lower wall along-vein transport tunnel according to the length of the through-vein tunnel determined in step S3 and the lower opening position of the chute determined in step S6.

[0052] In order to clearly explain the method for determining the pressure failure angle of the upper plate wedge, the present invention subdivides each stage into the mining stage, the preparation stage and the pressure-release development stage, and adopts methods such as field investigation, theoretical research, laboratory experiment, and numerical simulation to determine the damage range of the upper plate development project in the preparation stage. According to the relationship between the damage range of the upper plate development project in the preparation stage and the position of the empty area in the mining stage, the pressure failure angle β of the upper plate wedge is determined, the pressure-bearing area and the pressure-release area are divided, and the upper plate along-vein transportation laneway is arranged 1 in the pressure-release area to release the pressure effect of the upper plate wedge. According to the relationship between the inclination angle α of the upper plate of the ore body and the pressure failure angle β of the upper plate wedge, the inclination angle of the chute is determined. According to the position of the upper plate along-vein transportation laneway, the reasonable length of the vein-penetrating laneway, and the inclination angle of the chute, the upper and lower opening positions of the chute are determined. Finally, according to the position of the chute, the position of the lower plate along-vein transportation laneway is determined.

[0053] In the present invention, the pressure failure angle β of the upper plate wedge is determined according to the pressure failure range of the upper plate wedge, and the pressure-bearing area and the pressure-yielding area are divided, and the upper plate along-vein transport roadway is arranged in the pressure-yielding area, so as to avoid the upper plate along-vein transport roadway and the through-vein roadway being directly subjected to the pressure of the upper plate wedge, reduce the effect of the pressure of the upper plate wedge on the lower plate along-vein transport roadway and the chute through the loose body 18 in the goaf, improve the stability of the upper plate along-vein transport roadway, the through-vein roadway, the lower plate along-vein transport roadway and the chute, and extend the service life of the development project;

[0054] The method for determining the inclination angle of the chute according to the relationship between the inclination angle α of the upper plate of the ore body and the pressure failure angle β of the upper plate wedge-shaped body in the present invention can reduce the effect of the pressure of the upper plate wedge-shaped body on the chute through the loose body 18 in the goaf, improve the stability of the chute, and increase the service life of the chute. At the same time, the method can flexibly arrange the chute according to the ground pressure manifestation law of the upper plate wedge-shaped body, giving full play to the maximum advantage of the chute in circular transportation.

[0055] In the present invention, the upper plate along-vein transport lane, the through-vein lane, the lower plate along-vein transport lane and the chute form a complete circular transport system in the ore body, satisfying the circular transport function in the ore body;

[0056] In summary, the present invention not only avoids the damage of the wedge-shaped ground pressure to the development tunnel and the chute through the above method, but also ensures the normal function of the circular transportation.

[0057] It should be noted that the pressure-releasing development method in the present invention is applicable to the mining of inclined ore bodies of metal mines, and steeply inclined ore bodies refer to ore bodies with an inclination angle greater than 55°. The chute mentioned in the present invention is a top-down passage. After the ore is mined, it is poured into the chute through the preparatory stage segmented mining access 10 and the preparatory stage segmented lower plate along the vein transportation tunnel 11. The ore is quickly slid to the lowest transportation level of the stage by its own gravity; the stage refers to the unit divided by a certain height in the vertical direction of the ore body, and each stage represents a vertical height range.

[0058] The upper plate vein transport lane 1 in the yielding and pressure development stage, the upper plate vein transport lane 5 in the preparation stage, the upper plate vein transport lane 4 in the mining stage and the lower plate vein transport lane 3 in the yielding and pressure development stage, the lower plate vein transport lane 7 in the preparation stage and the lower plate vein transport lane 16 in the mining stage are the main lanes in the mine development system and are lanes excavated along the direction of the ore body. The vein-crossing lane 2 in the yielding and pressure development stage is used to connect the upper plate vein transport lane 1 in the yielding and pressure development stage and the lower plate vein transport lane 3 in the yielding and pressure development stage, and the three form a stage ring transportation system.

[0059] When arranging the chute, in addition to considering its inclination, factors such as the development of joints and fissures in the lower wall rock, the particle size, humidity, viscosity of the ore, the service life of the chute, and the mine production capacity must be considered.

[0060] In the present invention, when the inclination angle of the upper plate of the ore body is not less than the pressure failure angle of the upper plate wedge, the inclination angle of the chute is the inclination angle of the upper plate of the ore body; when the inclination angle of the upper plate of the ore body is less than the pressure failure angle of the upper plate wedge, the inclination angle of the chute is the pressure failure angle of the upper plate wedge.

[0061] Specifically, step S1 uses methods such as field investigation, theoretical research, laboratory experiments, and numerical simulation to determine the damage range of the upper plate wedge pressure on the development project in the preparation stage, and determines the pressure damage angle β of the upper plate wedge based on the relationship between the damage range of the upper plate development project in the preparation stage and the position of the void area in the mining stage.

[0062] Investigate the damage of the development project revealed during the mining and preparation stages on site, count the damaged parts of the tunnels, and mark the damaged parts on the drawings. The determination of rock mass mechanical parameters is to sample the ore and rock on site, process them into standard specimens, and then conduct rock mechanics tests in the laboratory to obtain the physical and mechanical parameters of the rock mass, providing a theoretical basis for numerical simulation. The numerical simulation method is to establish an ore body model based on the actual rock mass occurrence and the mechanical parameters of the rock, according to the actual mining conditions of the ore and rock, and conduct numerical simulation analysis on the model to determine the damage range and influence range of the upper wall wedge pressure during each stage of mining.

[0063] The method for determining the pressure failure angle β of the hanging wall wedge is to refer to the damage of the hanging wall project revealed on site and combine the results of numerical simulation to determine the damage boundary of the hanging wall wedge pressure on the hanging wall surrounding rock, connect the boundary point of the damage zone with the boundary point of the hanging wall in the upper mining stage, and the angle between this line segment and the horizontal line is the pressure failure angle β of the hanging wall wedge.

[0064] In step S2 of the present invention, the pressure-bearing area and the yielding area are divided according to the determined pressure failure angle β of the upper plate wedge-shaped body. With the line segment as the boundary, the upper plate side is the pressure-bearing area, and the lower plate side is the yielding area. The upper plate along-vein transport tunnel is arranged in the yielding area. The specific arrangement position should comprehensively consider the reasonable length of the tunnel through the vein, the inclination angle of the chute, and the position of the upper and lower openings of the chute, to ensure that the yielding development project forms a ring-shaped transportation system. In the present invention, the pressure failure range of the upper plate wedge-shaped body extends from top to bottom along the inclination of the ore body, and the general failure angle β = 75° ~ 90°.

[0065] By determining the pressure-bearing zone and the yield zone according to the above method, the pressure destruction zone of the upper plate wedge is accurately identified, reducing the safety accidents caused by the manifestation of the wedge-shaped ground pressure. The layout positions of the upper plate along-vein transport tunnels, through-vein tunnels, lower plate along-vein transport tunnels, and chutes are reasonably planned according to the pressure destruction zone of the upper plate wedge-shaped body, thereby avoiding the above-mentioned projects from being destroyed by the wedge-shaped ground pressure and extending the service life of the development project.

[0066] In step S3 of the present invention, according to the determined position of the upper plate along-vein transport lane, a reasonable length of the through-vein lane is determined taking into account the loading length of the straight section of the through-vein lane, the curvature radius of the intersection of the through-vein lane and the upper plate along-vein transport lane in the pressure-releasing development stage, the through-vein lane and the lower plate along-vein transport lane in the pressure-releasing development stage, and the position of the chute;

[0067] The ore mined in the stage needs to be loaded in the vein-crossing tunnel, and the length of the vein-crossing tunnel must be greater than the length of the entire train of mine cars. The curvature radius of the tunnel at the intersection of the vein-crossing tunnel and the upper plate along-vein transport tunnel in the pressure-releasing development stage, and the curvature radius of the tunnel at the intersection of the lower plate along-vein transport tunnel in the pressure-releasing development stage should be determined according to the length of the mine car. The curvature radius must meet the turning requirements of the mine car and the transportation equipment to avoid transportation difficulties or equipment damage due to too small a curvature radius. It is necessary to ensure that the mine car can smoothly turn from the upper plate along-vein transport tunnel in the pressure-releasing development stage and the lower plate along-vein transport tunnel in the pressure-releasing development stage to the vein-crossing tunnel.

[0068] Step S4, determining the inclination angle of the chute according to the relationship between the pressure failure angle β of the hanging wall wedge and the inclination angle α of the ore body hanging wall. When the inclination angle α of the ore body hanging wall is not less than the pressure failure angle β of the hanging wall wedge, the inclination angle of the chute is the inclination angle α of the ore body hanging wall; when the inclination angle α of the ore body hanging wall is less than the pressure failure angle β of the hanging wall wedge, the inclination angle of the chute is the pressure failure angle β of the hanging wall wedge.

[0069] This method of determining the chute can reduce the effect of the pressure of the upper wedge on the chute through the loose body 18 in the goaf, improve the stability of the chute, and increase the service life of the chute. At the same time, this method can flexibly arrange the chute according to the law of the wedge-shaped body ground pressure, giving full play to the maximum advantage of the chute in circular transportation.

[0070] Step S5, determining the upper opening position of the chute according to the number of sections in the preparation phase and the ore-discharging demand of the lowest section, combined with the ore-discharging demand of each section in the pressure-releasing development phase.

[0071] Figure 1 The preparation stage given in the specification is divided into 4 sections. In each section, a preparation stage segmented cutting tunnel 8 is made in the upper plate of the ore body. The ore body is withdrawn from the upper plate of the preparation stage segmented mining access 10 to the lower plate with the cutting tunnel as the free surface. The collapsed ore is loaded into the scraper and poured into the chute through the preparation stage segmented mining access 10 and the preparation stage segmented lower plate along the vein transportation tunnel 11. It slides to the lowest section of this stage, is loaded into the mine car in the vein crossing tunnel, and is transported to the main shaft through the upper plate along the vein transportation tunnel 1 of the pressure release development stage.

[0072] The selection of the location of the upper mouth of the chute should take into account factors such as rock stability and convenience of transportation. The upper mouth of the chute should be reasonably selected based on the actual situation of mining in each section at this stage.

[0073] Among them, the segmentation is the redivision of the stage in the vertical direction, and each segment can be regarded as an independent mining operation unit. According to the upper position of the chute and the inclination of the chute, starting from the upper position of the chute and extending downward along the inclination of the chute, the intersection of this straight line and the lowest level of the stage is the lower position of the chute.

[0074] In step S7 of the present invention, the position of the lower plate along-vein transport lane is determined according to the length of the through-vein lane and the position of the lower opening of the chute. The lower plate along-vein transport lane should be arranged in the stable rock mass of the lower plate, and keep a certain distance from the lower plate boundary of the ore body and the lower opening of the chute to avoid mutual influence between ore body mining, loading and unloading and transportation. At the same time, the lower plate along-vein transport lane serves the entire stage and has a long service life. It is necessary to ensure that the lane is not damaged and operates well.

[0075] The determination of the pressure failure angle of the upper plate wedge in the present invention can be carried out according to the following steps: Step A, on-site investigation: based on the damage of the upper plate engineering revealed on-site, preliminarily determine the scope of action of the pressure of the upper plate wedge, divide the pressure-bearing area and the pressure-yielding area, and provide an on-site basis for the numerical simulation of the pressure of the upper plate wedge; Step B, rock mass mechanical parameter determination: through on-site sampling and laboratory testing, obtain the physical and mechanical parameters of the ore body and the surrounding rock of the upper plate and the surrounding rock of the lower plate, and provide a theoretical basis for numerical simulation; Step C, establish a numerical simulation model: based on the occurrence and physical and mechanical parameters of the actual rock mass, According to the actual mining conditions of the ore body and the surrounding rocks of the upper and lower plates, a geometric model of the ore body and the surrounding rocks of the upper and lower plates is established; Step D, numerical simulation analysis: numerical simulation analysis is performed on the model to determine the pressure failure range and influence range of the upper plate wedge during the mining process at each stage; Step E, determination of the pressure failure angle of the upper plate wedge: referring to the damage conditions of the upper plate engineering exposed on site, combined with the results of numerical simulation, the damage boundary of the pressure of the upper plate wedge on the surrounding rocks of the upper plate is determined, the boundary point of the damage zone is connected with the boundary point of the upper plate in the upper mining stage, and the angle between this line segment and the horizontal line is the pressure failure angle of the upper plate wedge.

[0076] The present invention provides an important guarantee for the stage development project (upper plate along-vein transport lane, through-vein lane, lower plate along-vein transport lane, chute) to be protected from the damage of wedge-shaped body ground pressure. The damage of the development project will cause the annular transportation system to be unable to operate normally, and the ore recovered in each stage cannot be transported to the main shaft, which seriously affects the normal production of the mine. Therefore, the stability of the stage development project has a significant impact on the mine production. The present invention avoids the large-scale damage of the steeply inclined ore body stage development project to ground pressure, ensures the safe production and operation of the mine, and can bring significant economic benefits.

[0077] like Figure 1 As shown, the development project in the present invention also includes the segmented connecting tunnel 9, the ore bulk 17 and the boundary line 19 between the wedge-shaped body pressure-bearing zone and the pressure-releasing zone in the preparation stage.

[0078] By the present invention Figure 1 to Figure 7 It can be seen that the ground pressure of the wedge can be mechanically calculated through a geometric model.

[0079] The geopressure calculation process of the wedge-shaped body of the present invention is as follows:

[0080] When modeling, since the stress distribution state in each section of the wedge along the strike direction is the same, the wedge space problem is converted into a plane problem of elastic mechanics, and the length direction is regarded as unit 1. There are two stress states of the wedge, one is its own gravity, and the other is the support force of the bulk on the upper wall of the ore rock. According to the classical Jansen bulk pressure theory, in the case of a silo or similar silo with vertical walls, the horizontal pressure of the bulk is in a certain ratio to the vertical pressure:

[0081] P xy =KP z (1.1)

[0082] Where P z - Average vertical pressure on the bottom of the silo or silo-like silo, Pa;

[0083] P xy -Horizontal pressure on the side wall of the silo or silo-like material, Pa;

[0084] K-side pressure coefficient, θ is the internal friction angle of the bulk.

[0085] like Figure 2 As shown in the figure, the basic model of the semi-infinite asymmetric wedge is established, with the AB surface as the ground surface, the lengths of OA and OB as a1 and a2 respectively. As the mining depth increases, point O extends infinitely along the negative direction of the x-axis. When establishing the mechanical model, only the state of the constant body force under the self-weight ρg is considered, and the supporting effect of the bulk body of the collapse pit on the side wall is not considered. The angle between ρg and the positive direction of the x-axis is γ, and the angles between the wedge surfaces OA and OB on both sides of the wedge and the x-axis are α and β respectively. There is no surface force, so the boundary conditions are:

[0086]

[0087] General stress solution

[0088] In the polar coordinate system, the body force has potential, so there is a potential function V(r,θ), and the body force component f r 、f θ The relationship between the potential function V(r,θ) is:

[0089]

[0090] When the physical force is a constant ρg, Figure 2 The potential function V of the actual model body force is shown as:

[0091] V=-f(ar)cos(π-γ-θ)=ρg(ar)cos(γ+θ) (1.4)

[0092] Where ρ is the density of the elastic body, kg / m3;

[0093] g-gravitational acceleration, 9.8m / s2;

[0094] a-wedge length, m.

[0095] In general, the calculation under the action of body force is much more complicated than the calculation under the action of surface force. The actual model of the elastic body force can be transformed into a fictitious model of the same elastic body problem.

[0096] The stress components of ”' are σ r , σ θ , τ rθ , the fictitious model stress component σ r , σ θ , τ rθ , when solving stress boundary problems according to stress, if the body force is constant, only the stress function needs to be solved. In the rectangular coordinate system, if the body force is ignored, f x =f y =0, the stress function and the stress component satisfy equation (1.5). According to equation (1.6) the relationship between the polar coordinate system and the rectangular coordinate system, the relationship between the stress function and the stress component in the polar coordinate system is equation (1.7).

[0097]

[0098] In the process of solving the elastic stress of a semi-infinite wedge under its own weight, a fictitious model with zero body force in polar coordinates is generally constructed. Figure 2 The wedge model can be used to obtain the imaginary model Figure 3 (a), investigate the relationship between the linear distribution load and polar coordinates on the wedge surfaces OA and OB, Figure 3 The load distribution in (a) can be equivalent to Figure 3 The linear distributed load in (b) and Figure 3 The superposition of uniformly distributed loads in (c) is discussed below. Figure 3 (b) and Figure 3 Solution for the elastic stress in (c).

[0099] make Figure 3 The stress functions of the semi-infinite asymmetric wedge problems shown in (a), (b), and (c) are Satisfying the relationship in formula (1.8), the semi-inverse solution is used to obtain Afterwards

[0100]

[0101] Refer to the solution process of elastic stress under the self-weight of a semi-infinite wedge. It can be expressed as:

[0102]

[0103] In the formula, A1, B1, C1, and D1 are four constants to be determined.

[0104] The corresponding stress components in polar coordinates can be expressed as:

[0105]

[0106] The boundary conditions of the plane strain problem must satisfy the following equation:

[0107]

[0108] On the wedge surface OA (θ = α), the boundary conditions are:

[0109]

[0110] On the wedge surface OB (θ = -β), the boundary conditions are:

[0111]

[0112] Combining equations (1.9), (1.10), (1.11) and (1.12), we can solve for constants A1, B1, C1 and D1. The solution process uses the symbolic operation module sympy of the computer language python.

[0113]

[0114] According to the stress function shown in formula (1.8) Using formula (1.9), we can get Figure 3 The general solution for the stress of the asymmetric wedge shown in (b) under the action of its own weight is:

[0115]

[0116]

[0117] Refer to the solution process of elastic stress under the self-weight of a semi-infinite wedge. It can be expressed as:

[0118]

[0119] In the formula, A2, B2, C2, and D2 are four constants to be determined.

[0120] The corresponding stress components in polar coordinates can be expressed as:

[0121]

[0122] On the wedge surface OA (θ = α), the boundary conditions are:

[0123]

[0124] On the wedge surface OB (θ = -β), the boundary conditions are:

[0125]

[0126] Similarly, constants A2, B2, C2, and D2 can be solved. The solution process uses the symbolic operation module sympy of the computer language python.

[0127]

[0128] According to the stress function shown in formula (1.21) Using formula (1.9), we can get Figure 3 The general solution for the stress of the asymmetric wedge shown in (c) under the action of its own weight is:

[0129]

[0130] According to the stress superposition principle, Figure 3 The general solution for the stress of the asymmetric wedge shown in (a) under the action of its own weight is:

[0131] σ r =σ r1 +σ r2

[0132] =2r[A1cosθ+B1sinθ-3C1cos3θ-3D1sin3θ]-ρgrcos(γ+θ)-2A2cos2θ-2B2sin2θ+2C2θ-2D2+ρgacos(γ+θ) (1.32)

[0133] σ θ =σ θ1 +σ θ2

[0134] =6r[A1cosθ+B1sinθ+C1cos3θ+D1sin3θ]-ρgrcos(γ+θ)+2A2cos2θ+2B2sin2θ+2C2θ+2D2+ρgacos(γ+θ) (1.33)

[0135] τ rθ =τ rθ1 +τrθ2

[0136] =2r[A1sinθ-B1cosθ+3C1sin3θ-3D1cos3θ]+2A2sin2θ-2B2cos2θ-C2 (1.34)

[0137] When β = π / 2

[0138] like Figure 4 As shown, when γ = π, the stress of the asymmetric wedge under the action of its own weight is generally solved. The values ​​of Ai, Bi, Ci, Di (i = 1, 2) are as follows:

[0139]

[0140] From the above formula, the corresponding stress solution when γ = π is generally:

[0141] σ r =σ r1 +σ r2

[0142] =2r[A1cosθ+B1sinθ-3C1cos3θ-3D1sin3θ]+ρgrcosθ-

[0143] 2A2cos2θ-2B2sin2θ+2C2θ-2D2-ρgacosθ(1.76)

[0144] σ θ =σ θ1 +σ θ2

[0145] =6r[A1cosθ+B1sinθ+C1cos3θ+D1sin3θ]+ρgrcosθ+

[0146] 2A2cos2θ+2B2sin2θ+2C2θ+2D2-ρgacosθ(1.77)

[0147] τ rθ =τ rθ1 +τ rθ2

[0148] =2r[A1sinθ-B1cosθ+3C1 sin3θ-3D1cos3θ]+

[0149] 2A2sin2θ-2B2cos2θ-C2(1.78)

[0150] The present invention discloses multiple technical solutions, but does not provide any contrary technical inspiration.

[0151] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for deep pressure relief development of a steeply inclined ore body, characterized in that: The following steps are involved: Step S1, using field investigation, theoretical research, laboratory experiments, and numerical simulation methods to determine the damage range of the pressure of the upper plate wedge to the development project in the preparation stage, and determining the pressure damage angle of the upper plate wedge according to the damage range of the development project in the preparation stage and the position relationship of the empty area in the mining stage; Step S2, dividing the pressure-bearing area and the pressure-yielding area according to the pressure failure angle, arranging the upper wall along-vein transport lane in the pressure-yielding area to avoid the pressure effect of the upper wall wedge-shaped body; Step S3, determining the length of the through-the-vein roadway according to the position of the upper plate along-the-vein transport roadway, the loading length of the straight section of the through-the-vein roadway, the radius of curvature at the intersection of the through-the-vein roadway and the upper plate along-the-vein transport roadway, the radius of curvature at the intersection of the through-the-vein roadway and the lower plate along-the-vein transport roadway, and the position of the chute; Step S4, determining the inclination of the chute according to the relationship between the pressure failure angle and the inclination of the upper wall of the ore body; Step S5, determining the upper opening position of the chute according to the number of sections in the preparation stage and the ore-exporting demand of the lowest section, combined with the ore-exporting demand of each section in the pressure-releasing development stage; Step S6, determining the lower opening position of the chute according to the inclination angle of the chute in step S4 and the upper opening position of the chute in step S5; Step S7, determining the position of the lower wall along-vein transport tunnel according to the length of the vein-penetrating tunnel described in step S3 and the lower opening position of the chute described in step S6.

2. The method for deep pressure release and development of a steeply inclined ore body according to claim 1, characterized in that: The determination of the pressure failure angle comprises the following steps: Step A, on-site investigation: based on the damage of the hanging wall engineering revealed on-site, preliminarily determine the pressure action range of the hanging wall wedge, divide the pressure-bearing area and the pressure-yielding area, and provide on-site basis for the numerical simulation of the pressure of the hanging wall wedge; Step B, determination of rock mass mechanical parameters: through field sampling and laboratory testing, the physical and mechanical parameters of the rock mass are obtained to provide a theoretical basis for numerical simulation; Step C, establishing a numerical simulation model: based on the occurrence and physical and mechanical parameters of the actual rock mass and the actual mining conditions, a geometric model of the ore body and the surrounding rock of the upper wall and the surrounding rock of the lower wall is established; Step D, numerical simulation analysis: performing numerical simulation analysis on the model to determine the pressure damage range and impact range of the upper wall wedge during mining at each stage; Step E, determination of the pressure failure angle: referring to the damage of the upper plate project revealed on site and combining the results of numerical simulation, determine the damage boundary of the upper plate surrounding rock due to the pressure of the upper plate wedge, connect the boundary points of the damage zone due to the pressure of the upper plate wedge with the boundary points of the upper plate in the upper mining stage, and the angle between the line segment formed by connecting the boundary points of the damage zone with the boundary points of the upper plate in the upper mining stage and the horizontal line is the pressure failure angle.

3. The method for deep pressure release and development of a steeply inclined ore body according to claim 2, characterized in that: In step S1, the boundary point of the destruction zone and the boundary point of the upper plate are connected, and the angle between the line segment formed by connecting the boundary point of the destruction zone and the boundary point of the upper plate and the horizontal line that is less than 90° is the pressure destruction angle, the upper plate side of the pressure destruction angle is the pressure-bearing area, and the lower plate side of the pressure destruction angle is the pressure-yielding area.

4. The method for deep pressure release and development of a steeply inclined ore body according to claim 1, characterized in that: The pressure failure range of the upper plate wedge extends from top to bottom along the inclination of the ore body, and the pressure failure angle is 75° to 90°.

5. The method for deep pressure release and development of a steeply inclined ore body according to claim 1, characterized in that: When the inclination angle of the upper plate of the ore body is not less than the pressure failure angle, the inclination angle of the chute adopts the inclination angle of the upper plate of the ore body; when the inclination angle of the upper plate of the ore body is less than the pressure failure angle, the inclination angle of the chute adopts the pressure failure angle.

6. The method for deep pressure release and development of a steeply inclined ore body according to claim 1, characterized in that: First, the pressure failure angle is determined, and based on the pressure failure angle, the pressure-bearing zone and the pressure-yielding zone are delineated. Secondly, the position of the upper plate along-vein transport tunnel is determined within the pressure-yielding zone. Then, the length of the through-vein tunnel is determined. Next, the inclination angle of the chute, the position of the upper opening of the chute and the position of the lower opening of the chute are determined. Finally, the position of the lower plate along-vein transport tunnel is determined. While avoiding the pressure effect of the upper plate wedge, the normal circular transportation of the upper plate along-vein transport tunnel, the through-vein tunnel, the lower plate along-vein transport tunnel and the chute is ensured.

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