A new level development method of deep concave open pit under water pressure environment

Abstract

The present application relates to a kind of for deep recess open-pit new level development water pressure environment reconstruction efficient ditching method, the lithology and fracture distribution characteristics of rock mass in the in-and-out ditch ditching area are proved, and according to this, each construction section of in-and-out ditch channel is subdivided into water gushing area, conventional area and first blast area.In first blast area and water gushing area and outside, uniformly arrange precipitation well, outside, arrange drainage well, after the surface fissure water is drained in advance, from first blast section, it is formed to gather water loose blast pile by rapid penetration and blasting to both sides.In the pre-splitting blast hole drilled between drainage well and the first blast area and water gushing area of channel, bottom is strengthened charge and is simultaneously detonated with adjacent channel construction section, and through drainage passage is formed in the bottom of blast pile between drainage well and in-and-out ditch.In the completion of penetration and blasting, water pump in drainage well is full load continuous pumping, so that the water level of blast pile is lower than the operating surface of electric shovel, and electric shovel is combined with car flat car full section high continuous ditching to new level operating surface.The present application has the advantages of improving penetration and blasting effect, improving ditching efficiency, flexible selection of development opportunity etc..

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of open-pit mining, and particularly relates to a deep concave open-pit mine new level development water pressure environment reconstruction efficient trenching method suitable for rainy areas. BACKGROUND

[0002] Trenching operation is a new level development preparation work that must be carried out for open-pit mine deepening and continuous production. Compared with normal mining and stripping operation, it is located at the lowest part of the mining area and is greatly affected by gushing water, the operation surface is narrow and the blasting free surface is less, which is one of the weakest links of open-pit production, and seriously limits the production capacity of the open-pit mine, and has a significant impact on open-pit mine planning and mining layout, reserve of mining quantity, and stripping ratio balance.

[0003] With the continuous increase of mining depth, surface runoff and underground gushing water are collected in the shallow groundwater layer at the pit bottom, and it is difficult to discharge the broken powder slag during the process of roller drilling, which continuously erodes the hole wall, so that the broken rock blocks in the super-deep blasting area of the previous level and the affected area are loosened and collapsed, which easily causes the filling of broken blocks at the hole bottom or the blocking of large blocks in the hole, and causes large-scale hole problems such as hole loss, re-drilling, and increase of secondary holes, and blasting problems such as hole punching, root bottom, and high large block rate, which seriously affect the engineering quality and progress and greatly increase the processing cost of subsequent processes. After the channel area starts blasting, the hydraulic balance of the internal rock mass is destroyed, resulting in a large amount of gushing water collected in the loose blasting heap. On the one hand, the blasting heap quickly collects water to form a high-pressure water environment, which easily penetrates along the blasting fissure to the surrounding area, causing poor hole penetration effect, and on the other hand, the blasting heap in the trench continuously collects water, and the trenching cannot be continuously operated, and temporary drainage pits need to be arranged and pumps need to be installed for water pumping, which seriously restricts the trenching efficiency and affects the production safety. In addition, in the rainy areas in the south, the rainy season is long, the new level development period is limited, and the problems of frequent exposure of drilling and blasting, drainage and other problems during trenching are extremely easy to cause the lag of mining progress, and further cause the shortage of mining quantity, the difficulty of ore distribution and other production accidents.

[0004] Therefore, it is particularly urgent to develop a water pressure environment reconstruction efficient trenching method suitable for deep concave open-pit mine new level development in rainy areas to realize continuous, stable and efficient production. SUMMARY

[0005] The present application discloses a deep concave open-pit mine new level development water pressure environment reconstruction efficient trenching method to solve any of the above and other potential problems of the prior art.

[0006] In order to solve the above technical problems, the technical scheme of the present application is as follows: a deep concave open-pit mine new level development water pressure environment reconstruction efficient trenching method, which comprises the following steps:

[0007] S1) The lithology and fracture distribution characteristics of the rock mass in the in-out trenching area are verified, the in-out trench channel layout is optimized according to the lithology and fracture development, and the in-out trench channel is divided into water gushing area, conventional area and first blasting area;

[0008] S2) The precipitation wells are uniformly arranged in the first blasting area and the water gushing area in the in-out trench channel, the drainage wells are arranged outside the first blasting area and the water gushing area in the trench channel, and the advanced drainage is carried out. After drainage, the water gushing area is formed by rapidly penetrating and blasting from the first blasting section to both sides, and the water gushing area is formed by rapidly penetrating and blasting from the first blasting section to both sides.

[0009]

[0010] S3) The pre-splitting blast holes are drilled between the drainage wells and the first blasting area and the water gushing area in the trench channel, the bottom is reinforced with explosive and is simultaneously detonated with the adjacent trench construction section, and the through drainage channel is formed between the drainage wells and the bottom of the in-out trench blasting heap.

[0011] Further, the specific steps of the S1) are:

[0012] S1.1) The in-out trenching area is preliminarily selected according to the mine transportation system, the dense network physical exploration lines similar to the blast hole network are arranged, and the water exploration holes are drilled at the key nodes to check the lithology, water inflow and fracture zone development characteristics in the area, and the in-out trenching direction and starting position are adjusted to determine the final scheme.

[0013] S1.2) According to the blast hole network arrangement and the number of drill holes that can be drilled by the rotary drill rig per day platform shift for new level development, the number of construction sections is determined, and each section of the in-out trench is divided into three types of water gushing area, conventional area and first blasting section, wherein the physical exploration line network interval is 5-10m, the number of construction sections is 5-8 sections, and the number of water exploration holes is ensured to be not less than 1 per construction section.

[0014] Further, the water gushing area, conventional area and first blasting section in the S1.2) are divided according to the detailed exploration results of the lithology and fracture distribution in the in-out trench, wherein the water gushing area is the area with poor lithology or developed fractures selected according to the exploration geophysical prospecting and water exploration drill hole data in the in-out trench;

[0015] The conventional area is the area with hard lithology and no developed fractures selected according to the exploration geophysical prospecting and water exploration drill hole data in the in-out trench;

[0016] The first blasting section is a construction section with hard lithology and developed fractures in the upper part of the in-out trench.

[0017] Further, the specific steps of the S2) are:

[0018] ​S2.1) several precipitation wells are arranged in the gushing area of the channel or on the side of the main gushing source outside the channel, and several drainage wells are arranged at the first blasting section and outside the gushing area at a distance of 1.5-2.0 times the minimum resistance line, respectively, for advanced drainage;

[0019] S2.2) After the surface fissure water in the area to be excavated is drained, the first blasting section is started as the starting section, the perforation blasting is started, the charge is increased during the first face blasting, and then the construction section is quickly pushed forward along the front and rear of the channel, so that all the in-and-out channels in the channel are formed into a water-collecting loose blasting heap;

[0020] Further, the number of the precipitation wells in S2.1) is 4-8, the diameter is 0.5-1.5 m, and the depth is 0.4-0.5 times the bench height of the open pit, which is 6-7.5 m when the bench height is 15 m. The precipitation wells are destroyed together with the trench blasting after the perforation of the construction section.

[0021] Further, the number of the drainage wells in S2.1) is 2-3, and the depth is 1.2-1.5 times the bench height of the open pit, which is 18-24 m when the bench height is 15 m. The drainage wells can be abandoned after the trenching is completed and the new horizontal drainage system is established, and are destroyed together with the slope expansion engineering.

[0022] Further, the specific steps of S3) are:

[0023] S3.1) One or two straight sections of through-drainage channels are arranged between the drainage wells and the first blasting section and the gushing area of the channel, and a row of dense pre-splitting blast holes are drilled along the designed through-drainage channels;

[0024] S3.2) The charge at the bottom of the pre-splitting blast hole is increased, and the length of the filling at the upper part is increased. The adjacent construction section of the channel is simultaneously initiated, a large number of blast-induced fractures are generated in the rock mass between the bottom of the drainage well and the bottom of the in-and-out channel blasting heap on the basis of the original micro-fractures or closed fractures, and a directional opening through-fracture zone drainage channel is formed.

[0025] Further, the pre-splitting blast hole in S3.1) has a depth of 2-3 m greater than the bench height of the open pit, which is 17-18 m when the bench height is 15 m. The blast holes are spaced at 10-12 times the diameter of the drill, which is 2.5-3.0 m when the diameter of the roller drill is 250 mm.

[0026] The length of the charge at the bottom of the pre-splitting blast hole in S3.2) is not less than the interval of the pre-splitting blast hole, and the length of the filling at the upper part of the pre-splitting blast hole is not less than the minimum resistance line of the mine.

[0027] Further, the total power of the water pump in S4) needs to be greater than 2-3 times the maximum gushing amount of the trenching in previous years.

[0028] The beneficial effects of the present application are that due to the adoption of the above technical solutions have the following characteristics:

[0029] (1) Good penetration effect. The dewatering well is arranged in the water-rich section outside the in-gouge and out-gouge, which effectively drains the water in the rock fissures, especially the water in the upper broken zone caused by the super-deep blasting of the previous level, thereby improving the borehole penetration effect, improving the drilling efficiency, avoiding a large number of waste holes caused by borehole collapse, ensuring the effective depth of the borehole, reducing the frequency of re-drilling and hole loss, and effectively improving the blasting quality (root and large block);

[0030] (2) High efficiency of gouging. The drainage well is arranged outside the in-gouge and out-gouge, and water is continuously pumped after the blast pile is formed, which can effectively drain the water in the blast pile and control the water level in the blast pile, thereby reducing or even eliminating the need to arrange a mobile drainage pit in the blast pile during the gouging process, thereby shortening the time for digging the drainage pit and installing the water pump pipeline, and greatly improving the gouging efficiency;

[0031] (3) More flexible selection of development time. Due to the influence of rainfall and underground water gushing, the new level development time in southern open-pit mines generally needs to be selected in the dry season for more than a month, and is greatly affected by typhoons and other weather conditions, so the development time is not fixed every year, which has a great impact on the production plan. The method described in the present application can actively discharge shallow fissure water and internal accumulated water in the blast pile by using dewatering wells and drainage wells, which creates good conditions for the gouging and blasting operation, effectively shortens the total gouging period, and thus makes the selection of development time more extensive and flexible;

[0032] At the same time, this method can not only actively reduce the water pressure in the channel area, greatly improve the perforation rate, and improve the blasting effect, but also can complete the advanced drainage of the internal water in the blast pile, avoid frequent excavation of temporary drainage pits and pumping for water pumping and drainage, realize efficient and continuous operation of gouging, solve the adverse effects of water gushing on new level development from the source, quickly complete the new level gouging project, and ensure the continuous, stable and efficient production of open-pit mines. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a three-dimensional schematic diagram of the method for reconstructing the water pressure environment of the new level development of the deep concave open-pit mine.

[0034] Figure 2 It is a schematic diagram of the exploration line and drilling arrangement and water gushing feature partitioning in the method of the present application;

[0035] Figure 3 It is a schematic diagram of the combined arrangement and design of the dewatering well and drainage well in the in-gouge and out-gouge of the method of the present application;

[0036] Figure 4 It is a schematic diagram of the effect of the dewatering well and drainage well during the perforation and blasting operation in the in-gouge and out-gouge of the method of the present application;

[0037] Figure 5 This is a schematic diagram of the trenching and blasting operations in the method of the present invention.

[0038] Figure 6 This is a schematic diagram of the widening operation in the method of the present invention;

[0039] Figure 7 This is a schematic diagram of the formation of the new water tank in the method of the present invention;

[0040] Figure 8 for Figure 4 Schematic diagram of the AA section for explosive drainage;

[0041] Attached image:

[0042] Ⅰ. Ditch, Ⅰ-1 Entrance / Exit Ditch, Ⅰ-2 Sectional Ditch, Ⅰ-1a Water Inrush Area, Ⅰ-1b Conventional Area, Ⅰ-1c First Blasting Section, Ⅱ. Working Side, 1. Exploration Drill Hole, 2. Exploration Line, 3a. Dewatering Well, 3b. Drainage Well, 4a. Temporary Water Reservoir, 4b. New Horizontal Temporary Water Reservoir, 5a. Blasting Hole, 5b. Pre-splitting Blasting Face, 6. Blasting Pile, 7. Road, 8. Ditch Side Slope, 9. Shovel-shaped Working Face, 10. New Horizontal Working Face, 11a. Original Fissure, 11b. Blasted Fissure, 12. Well-type Submersible Pump, 13. Water Level Monitor, 14. Flow Meter, 15. Drainage Pipe, 16a. Perforation Control Water Level Line, 16b. Trenching Control Water Level Line. Detailed Implementation

[0043] The technical solutions of various embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without innovative labor are within the scope of protection of the present invention.

[0044] A highly efficient trenching method for recreating the water pressure environment in new horizontal development of deep open-pit mines, the method comprising the following steps:

[0045] S1) Explore the lithology and fracture distribution characteristics of the rock mass in the trenching area, optimize the layout of the trenching channel according to the hardness of the lithology and the development of fractures, and subdivide the trenching channel into water inrush area, conventional area and first blasting area.

[0046] S2) Dewatering wells are evenly arranged inside and outside the first blasting area and water inrush area in the ditch. Drainage wells are arranged outside the first blasting area and water inrush area in the ditch, and advanced drainage is carried out. After drainage, the blasting is carried out quickly from the first blasting section to both sides to form a water-collecting loose blast pile.

[0047] S3) Drill pre-splitting holes between the drainage well and the first blasting zone and the water inrush zone of the trench, reinforce the bottom charge and detonate simultaneously with the adjacent trench construction sections, forming a through drainage channel at the bottom of the drainage well and the blast pile in the trench.

[0048] S4) After the completion of the blasting, the water pump in the hydrophobic well is full load to continuously pump water, so that the water level of the blast pile is lower than the working surface of the electric shovel, and the electric shovel cooperates with the truck flat car to continuously dig the ditch to the new level working surface.

[0049] Further, the specific steps of S1) are:

[0050] S1.1) According to the optimal preliminary selection of the mine transportation system, the in-out ditch trenching area is selected, a dense network of physical exploration lines similar to the blast hole network is arranged, and water exploration holes are drilled at key nodes to investigate the lithology, water inflow, and fracture zone development characteristics in the area, and the in-out ditch trenching direction and starting position are adjusted to determine the final scheme;

[0051] S1.2) According to the blast hole network arrangement and the number of rotary drill rigs available for new level development per day shift, the number of construction segments is determined, and each segment of the in-out ditch is divided into three types: water inflow area, conventional area, and first blast segment, wherein the physical exploration line network interval is 5-10m, the number of segments for construction is 5-8 segments, and the number of water exploration holes ensures that each construction segment is not less than 1.

[0052] Further, the water inflow area, conventional area, and first blast segment in S1.2) are divided according to the detailed exploration results of the lithology and fracture distribution in the in-out ditch, wherein the water inflow area is a region with poor lithology or developed fractures selected according to exploration geophysical and water exploration drilling data in the in-out ditch;

[0053] The conventional area is a region with hard lithology and undeveloped fractures selected according to exploration geophysical and water exploration drilling data in the in-out ditch;

[0054] The first blast segment is a construction segment with hard lithology and developed fractures in the upper part of the in-out ditch.

[0055] Further, the specific steps of S2) are:

[0056] S2.1) A number of dewatering wells are arranged in the water inflow area of the ditch or on the side of the main water inflow source outside the ditch, and a number of drainage wells are arranged at a distance of 1.5-2.0 times the minimum resistance line from the first blast segment and the water inflow area, respectively, for advanced drainage;

[0057] S2.2) After the surface fissure water in the trenching area is drained, the first blast area is started as the starting segment for perforation blasting, and the charge is increased during the first blasting, and then the construction segments are rapidly advanced along the ditch, and the entire ditch in the in-out ditch is formed into a water collection and loose blast pile;

[0058] Further, the number of the dewatering wells in S2.1) is 4-8, the diameter is 0.5-1.5 m, and the depth is 0.4-0.5 times of the bench height of the open-pit mine, i.e. 6-7.5 m when the bench height is 15 m. The dewatering wells are destroyed together with the trench blasting after the completion of the construction section perforation.

[0059] Further, the number of the dewatering wells in S2.1) is 4-8, the diameter is 0.5-1.5 m, and the depth is 0.4-0.5 times of the bench height of the open-pit mine, i.e. 6-7.5 m when the bench height is 15 m. The dewatering wells are destroyed together with the trench blasting after the completion of the construction section perforation.

[0060] Further, the specific steps of S3) are as follows:

[0061] S3.1) arranging 1-2 straight sections of the through dewatering channel between the dewatering wells and the first blasting area and the water gushing area of the trench, and drilling a row of dense pre-splitting blast holes along the designed through dewatering channel;

[0062] S3.2) increasing the charge amount at the bottom and the filling length at the upper part of the pre-splitting blast hole, simultaneously initiating blasting with the adjacent trench construction section, and generating a large number of blast-induced fissures in the rock mass between the bottom of the dewatering well and the bottom of the blasting heap of the in-and-out trench on the basis of the original microfissures or closed fissures, to form a directional opening through fissure zone dewatering channel

[0063] Further, the pre-splitting blast hole in S3.1) has a depth of 2-3 m greater than the bench height of the open-pit mine, i.e. 17-18 m when the bench height is 15 m; and the blast holes are spaced apart by 10-12 times the diameter of the blast hole drilling machine, i.e. 2.5-3.0 m when the diameter of the roller bit is 250 mm.

[0064] The length of the charge at the bottom of the pre-splitting blast hole in S3.2) is not less than the interval of the pre-splitting blast holes, and the filling length at the upper part of the pre-splitting blast hole is not less than the minimum resistance line of the mine.

[0065] Further, the total power of the water pump in S4) needs to be 2-3 times greater than the maximum gushing water amount of the trenching in previous years.

[0066] Embodiment:

[0067] As shown in Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 , the embodiment of the present application provides a deep recess open-pit mine new level development water pressure environment reconstruction efficient trenching method, which comprises the following steps:

[0068] (1) To explore the channel [I] and the surrounding area, according to the water inflow and rock mass characteristics, the area to be excavated is divided into water inflow area [I-1a] and conventional area [I-1b];

[0069] (2) The rotary drilling rig is used to drill the dewatering well [3a] in the water inflow area [I-1a] and install the well submersible pump. After the water level drops, the area with hard lithology is selected as the first blast section [I-1c], and the loose blast pile [6] is formed by rapid perforation blasting to collect the surrounding water inflow;

[0070] (3) The dewatering well [3b] is arranged outside the ditch, which is connected with the bottom of the blast pile by controlled blasting, and the high-power water pump

[12] is installed to continuously pump water to ensure that the water level in the blast pile is lower than the control water level line [16b] of the ditch;

[0071] (4) After the perforation blasting in the in-and-out ditch is completed, the shovel cooperates with the truck flat car to excavate the whole section continuously to the new level working surface

[10] .

[0072] In order to further illustrate the superiority of the ditch excavation method, the new level development project of open-pit mine is combined to further illustrate the ditch excavation operation.

[0073] ① The new level development ditch excavation method uses geophysical prospecting technology and drilling water exploration hole combined way to arrange water exploration drill hole [1] and dense hole network measuring line [2] in the ditch [I] after being leveled by the bulldozer, to obtain the internal water distribution and lithological characteristics of the in-and-out ditch [I-1] area, further analyze and divide the area with large water inflow as the water inflow area [I-1a], and the area with small water inflow as the conventional area [I-1b], and select the area with developed fissures, hard lithology and close to the ditch bottom in the water inflow area as the first blast section [I-1c];

[0074] ② According to the single well dewatering range and water inflow distribution characteristics, the combined arrangement scheme of dewatering well [3a] and dewatering well [3b] is developed, the rotary drilling rig is used to drill the dewatering well [3a] in the water inflow area [I-1a] and the dewatering well [3b] outside the first blast section [I-1c], and the well submersible pump

[12] and the dewatering pipeline

[15] are quickly installed for drainage, after the water level drops, the perforation blasting work of the first blast section [I-1c] is completed, the loose blast pile [6] is formed to collect the surrounding water inflow, at the same time, the pre-splitting blasting surface [5b] is formed between the blast pile [6] and the dewatering well [3b], the blast-induced fissure [11b] is further generated on the basis of the original fissure [11a], which is convenient for the rapid drainage of the blast pile [6] water collection;

[0075] ③ The water level in the blast pile [6] is controlled to be lower than the perforation control water level line [16a], and the whole section high one-time perforation blasting operation is completed in each section of the in-and-out ditch [I-1] area, in which the charge quantity and the dense hole network parameters are appropriately increased to enhance the blasting effect;

[0076] ④Regulate the water level in the blast pile to be lower than the trench control water level line [16b], and use the electric shovel combined with the car flat car mode to continuously excavate the trench in each section of the in-out trench [I-1] area, while arranging the perforation blasting operation near the bottom of the section trench [I-2], after the trench reaches the bottom, further excavate the section trench blast pile horizontally, quickly form the blasting free face;

[0077] ⑤After the section trench is excavated, quickly expand the side and mine near the temporary water sump [4a], form a new horizontal temporary water sump [4b] when a larger operation surface is formed, build a new horizontal drainage system, and blast the abandoned drainage well and the last horizontal temporary water sump. At this time, the new horizontal development project is completed.

[0078] The channel [I] includes an in-out trench [I-1] and a section trench [I-2], wherein the in-out trench [I-1] is arranged with a gentle inclination, the length is related to the transport car and the arrangement of the car, the width is related to the climbing ability of the transport car, and the section trench [I-2] is arranged horizontally, the length is equivalent to the new horizontal length (or width), and the width is the same as or slightly larger than that of the in-out trench [I-1];

[0079] The water exploration drill hole [1] is a preliminary judgment of the perforation hole forming rate in the in-out trench [I-1] area, which is convenient for developing the perforation and blasting construction sequence scheme, and preferably uses the drilling parameters to reflect the lithology, the imaging photography in the hole to reflect the fracture development characteristics and the water gushing situation, and the number of holes is ensured to be one for each blasting section of the in-out trench [I-1];

[0080] The exploration survey line [2] is a preliminary judgment of the water gushing fracture zone distribution in the in-out trench [I-1] area, and the dense hole network ground penetrating radar technology is preferably used for full coverage exploration, the grid survey line is not less than 3 along the direction of the in-out trench [I-1], and one survey line is ensured for each blasting section of the in-out trench [I-1] in the vertical direction of the in-out trench [I-1];

[0081] The water gushing area [I-1a] is an area with poor lithology or developed fractures in the in-out trench [I-1] according to the exploration geophysical prospecting and water exploration drill hole data;

[0082] The conventional area [I-1b] is an area with hard lithology and undeveloped fractures in the in-out trench [I-1] according to the exploration geophysical prospecting and water exploration drill hole data;

[0083] The first blasting section [I-1c] is a certain area with hard lithology and developed fractures in the middle and upper parts in the conventional area [I-1b], which is preferably near the bottom of the in-out trench [I-1];

[0084] The precipitation well [3a] mainly plays a role of improving the penetration effect, is generally arranged inside or outside the channel water gushing area [I-1a], the diameter is determined according to the drilling equipment, water gushing amount and water pump size, preferably 0.5-1.5 m, the depth is 0.4-0.5 times of the open-pit bench height, preferably 6-7.5 m for 15 m bench height, the number can be designed according to the water gushing amount and single well drainage capacity, preferably 4-8, and the precipitation well is destroyed together with the ditch blasting after the completion of the construction section perforation;

[0085] The drainage well [3b] mainly plays a role of draining the accumulated water of the blasting, is generally arranged outside the water gushing area [I-1a], the diameter is consistent with the precipitation well [3a], and can be appropriately widened according to the required drainage demand, preferably 1-2 m, the depth is 1.2-1.5 times of the open-pit bench height, preferably 18-24 m for 15 m bench height, the number can be designed according to the water gushing amount and single well drainage capacity, preferably 2-3, and the drainage well can be abandoned after the completion of the ditching and the establishment of the new horizontal drainage system and is destroyed together with the slope expansion engineering;

[0086] The pre-splitting blasting surface [5b] is a low-disturbance directional channel between the channel blasting accumulation [6] and the drainage well [3b] by controlled blasting, preferably a row of dense pre-splitting blasting holes is arranged along the drainage well [3b] perpendicular to the in-and-out ditch [I-1], a large number of blasting fissures [11b] are generated on the basis of the non-penetrating original microfissure or closed fissure [11a], and the open-through fissure water gushing channel is formed;

[0087] The penetration control water level line [16a] and the ditching control water level line [16b] correspond to different stages and different needs of the new horizontal ditching operation respectively, the former is for the purpose of reducing the internal fissure water of the rock mass to enhance the penetration hole formation rate, and the latter is for the purpose of draining the accumulated water in the blasting to realize the continuous ditching operation.

[0088] In summary, the application of the technical method in the deep new horizontal development of a large deep open-pit copper mine in China shows that, compared with the prior art, the penetration hole formation rate is significantly improved, the blasting effect is improved, the continuous ditching is realized, the ditching construction period is effectively shortened, and the safety of the construction personnel and equipment is ensured.

[0089] The above describes in detail a deep open-pit mine new horizontal development water pressure environment reconstruction efficient ditching method provided by the embodiments of the present application. The above description of the embodiments is only used to help understand the method and its core idea of the present application; meanwhile, for those skilled in the art, the specific implementation and application range will be changed according to the idea of the present application, and the above description should not be understood as a limitation of the present application.

[0090] As used in the specification and claims, certain terms have particular meanings. One skilled in the art will understand that different manufacturers can refer to a component by different names. The specification and claims should not be construed as limited to components by a particular name, but should be construed by the component's function. As used in the specification and claims, "comprising" and "including" are meant to be interpreted as specifying open-ended claims that are not limited to the listed elements. "Approximately" means within an acceptable error range for the corresponding function, which will vary from one context to another. The description that follows is intended to provide a better understanding of the preferred embodiments of the present application, and is not intended to be a complete description of all possible embodiments of the present application. The description serves only to illustrate the general principles of the present application, and is not meant to limit the present application to specific embodiments.

[0091] It should also be noted that the terms "comprising," "including," and "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, product, or composition that comprises a list of elements is not necessarily limited to only those elements but can include other elements not expressly listed or inherent to such process, product, or composition. In other words, "comprising" means "including, but not limited to."

[0092] It should be understood that the term "and / or" as used herein is merely an open joining of two independent items, and is not intended to imply that the joined items are to be combined in the same manner. In other words, "and / or" as used herein merely means that the associated listed items are one or both be present in order for the substance, mixture, or composition to be considered within the scope of the present application.

[0093] The above specification and examples provide a complete description of the application. Since many embodiments of the application can be made without departing from the spirit and scope of the application, certain aspects of the application could be embodied within a number of other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. A method for reconstructing efficient trenching in a deep recess open-pit mine new level development under water pressure environment, characterized in that, The method comprises the following steps: S1) proving the lithology and fracture distribution characteristics of the rock mass in the in-out trench trenching area, optimizing the in-out trench channel layout according to the lithology and fracture development, and subdividing the in-out trench channel into water gushing area, conventional area and first explosion area; S2) uniformly arranging the precipitation wells in the first explosion area and the water gushing area, arranging the drainage wells outside the first explosion area and the water gushing area, and carrying out advanced drainage, and after drainage, forming a water collecting loose explosion heap by rapidly penetrating and exploding from the first explosion area to both sides; S3) drilling pre-splitting blast holes between the drainage wells and the first explosion area and the water gushing area, strengthening the charge at the bottom of the pre-splitting blast hole and simultaneously initiating the adjacent channel construction section, and forming a through drainage channel between the drainage well and the bottom of the explosion heap; S4) after the penetration and explosion are completed, the water pump in the drainage well is continuously pumped at full load, so that the water level of the explosion heap is lower than the working face of the electric shovel, and the electric shovel cooperates with the truck flat car to continuously excavate the whole section to the new level working face.

2. The method of claim 1, wherein, The specific steps of S1) are: S1.1) According to the optimal preliminary selection of the mine transportation system, the in-out trench trenching area is selected, the dense network physical exploration line similar to the blast hole network is arranged, and the water exploration hole is drilled at the key node to check the lithology, water gushing amount and fracture zone development characteristics in the area, and the in-out trench excavation direction and starting position are adjusted to determine the final scheme; S1.2) According to the blast hole network arrangement and the available rotary drill rig one day shift drilling hole number for new level development, the construction section number is determined, and each section of the in-out trench is divided into three types of water gushing area, conventional area and first explosion area, wherein the physical exploration line network interval is 5-10m, the construction section number is 5-8 sections, and the water exploration hole number ensures that each construction section is not less than 1.

3. The method of claim 2, wherein, The water gushing area, conventional area and first explosion area in S1.2) are divided according to the detailed exploration results of the lithology and fracture distribution in the in-out trench, wherein the water gushing area is the area with poor lithology or developed fractures in the in-out trench selected according to the exploration geophysical exploration and water exploration hole data; The conventional area is the area with hard lithology and no developed fractures in the in-out trench selected according to the exploration geophysical exploration and water exploration hole data; The first explosion area is a construction section with hard lithology and developed fractures in the upper part of the in-out trench.

4. The method of claim 1, wherein, The number of precipitation wells in S2) is 4-8, the diameter is 0.5-1.5m, the depth is 0.4-0.5 times the bench height of the open pit mine, and the precipitation well is destroyed with the trench blasting after the completion of the drilling of the construction section.

5. The method of claim 1, wherein, The number of drainage wells in S2) is 2-3, the depth is 1.2-1.5 times the bench height of the open pit mine, and the drainage well can be abandoned after the completion of the trenching and the establishment of the new level drainage system, and is destroyed with the slope expansion engineering.

6. The method of claim 1, wherein, The depth of the pre-splitting blast hole in S3) is greater than 2-3m of the bench height of the open pit mine, and the pre-splitting blast hole interval is 10-12 times the diameter of the blast hole drill; The pre-splitting blast hole bottom charge length is not less than the pre-splitting blast hole interval, and the pre-splitting blast hole upper filling length is not less than the minimum resistance line of the mine.

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