Construction method of screen in underground mine chute

Abstract

This invention provides a method for constructing a grid screen in an underground mine chute, comprising the following steps: backfilling the chute; installing positioning I-beams at opposite ends of the chute opening; installing a lower layer of square steel between the positioning I-beams at both ends of the opening; constructing an upper layer of square steel crosswise above the lower layer, and welding the upper and lower layers together using connectors to form a single structure, thus obtaining the grid screen to be poured; installing a pouring template on the outside of the grid screen; removing the positioning I-beams and pouring the foundation in the foundation pouring space; and completing the grid screen construction after the foundation has solidified. This invention solves the problems of traditional mine chute grid screen construction methods, which involve pouring the foundation before installing the grid screen and the high-altitude work required for workers inside the chute during installation, resulting in significant limitations imposed by construction conditions, long construction periods, and high construction risks.

Description

Technical Field

[0001] This invention relates to the field of mining construction technology, and more specifically, to a method for constructing a grid screen in an underground mine chute. Background Technology

[0002] Mine ore passes are critical engineering projects during the infrastructure and mining phases of underground mines, impacting the entire mine's production system. This is especially true for mines currently operating under a "mine-for-mine" development model, where the ore pass hoisting system is paramount. Since the ore pass system ultimately lifts a portion of the entire mine, its early completion and commissioning is a top priority for every mine. Most mine ore passes are loaded by trucks or loaders. Due to safety requirements, screens and ore pass blocking systems need to be installed above the passes, resulting in complex processes, high construction difficulty, long construction periods, and persistently high costs and inefficiencies.

[0003] The current traditional construction method for grid screens in mine chutes involves first pouring the foundation around the chutes and then installing the grid screens. This method is subject to significant construction constraints and has a long construction period. Furthermore, during the installation of the grid screens, manual labor is required inside the chutes to perform operations such as fixing the ends of the grid screens and installing the grid screen plates. Since the interior of the chutes is a hollow structure, safety precautions must be taken. This is considered high-altitude work, which poses construction risks and results in low construction efficiency. Summary of the Invention

[0004] In view of the above problems, the purpose of this invention is to provide a construction method for underground mine chute screens, so as to solve the problems of the traditional construction method of mine chute screens in the prior art. Because the foundation is poured first and then the screen is installed, and the construction personnel are working at height inside the hollow chute when installing the screen, there are problems such as being greatly restricted by construction conditions, long construction period, and high construction risk factor.

[0005] This invention provides a method for constructing a screen in an underground mine chute, comprising the following steps:

[0006] S1. Backfill the chute so that the gap between the top surface of the backfill and the opening of the chute reaches a preset height.

[0007] S2. Using the open ceiling as the construction space for the grid screen, positioning I-beams are installed at both opposite ends of the wellhead of the chute, and both ends of the positioning I-beams are fixed to the outside of the chute by the first vertical fixing member.

[0008] S3. Install a lower square steel between the positioning I-beams located at both ends of the wellhead, and fix both ends of the lower square steel to the outside of the chute by the second vertical fixing member.

[0009] S4. An upper layer of square steel is erected crosswise above the lower layer of square steel. The two ends of the upper layer of square steel are respectively fixed to the outside of the chute by a third vertical fixing member. The upper layer of square steel and the lower layer of square steel are welded and fixed together as a whole structure using connectors to obtain the grid screen to be poured. The hole formed by the intersection of the upper layer of square steel and the lower layer of square steel is used as the grid screen hole.

[0010] S5. Install a casting template on the outside of the screen to be cast, and tie and fix the end of the screen to be cast to the casting template so that the screen to be cast is fixed in the middle of the casting template, and use the casting template and the outer wall of the chute as the foundation casting space.

[0011] S6. Remove the positioning I-beam and carry out foundation pouring construction in the foundation pouring space. After the poured foundation has solidified, complete the grid screen construction of the chute.

[0012] Furthermore, in a preferred embodiment, the backfilling of the chute, such that the gap between the top of the backfill and the opening of the chute reaches a preset height, includes:

[0013] Construct a vehicle blocking facility on the outside of the wellhead in the transport direction, use transport vehicles to transport slag and stone, and block the truck bed of the transport vehicle to unload the slag and stone in the truck bed into the interior of the well.

[0014] The gap between the backfill surface of the slag and the wellhead of the chute is made to reach a preset height.

[0015] Furthermore, in a preferred embodiment, the construction vehicle barrier includes:

[0016] A wheel-stop channel steel is installed on the outside of the wellhead in the transport direction, and both ends of the wheel-stop channel steel are fixed to the top surface of the roadway by round steel anchor rods.

[0017] Furthermore, a preferred embodiment includes, before the step of using a transport vehicle to transport the slag and using the vehicle-stopping device to block the truck bed of the transport vehicle so as to unload the slag in the truck bed into the interior of the chute, the following steps are also included:

[0018] At least two layers of geotextile are laid around the opening of the chute so that the transport vehicle can stop on the geotextile to unload the slag and stone.

[0019] Furthermore, a preferred embodiment is that the preset height is 1.5 meters to 1.6 meters.

[0020] Furthermore, in a preferred embodiment, the first vertical fixing member is a round steel anchor rod; and / or, the second vertical fixing member is a round steel anchor rod; and / or, the third vertical fixing member is a round steel anchor rod.

[0021] Furthermore, in a preferred embodiment, the lower square steel is perpendicular to the transport direction, and the upper square steel is parallel to the transport direction.

[0022] Furthermore, a preferred embodiment is that the step of welding and fixing the upper square steel and the lower square steel into an integral structure using connectors to obtain the grating to be cast includes:

[0023] A right-angled triangular connector is placed between the upper square steel and the lower square steel.

[0024] The two right-angled sides of the right-angled triangular connector are welded to the top surface of the lower square steel and the side surface of the upper square steel, respectively, so that the upper square steel and the lower square steel form an integral structure.

[0025] Furthermore, a preferred option is that the casting template is a wooden template.

[0026] Furthermore, a preferred approach is to complete the sieve construction of the chute after removing the positioning I-beams and constructing the foundation in the foundation pouring space, and after the foundation has solidified.

[0027] The foundation pouring construction uses concrete as the pouring material;

[0028] After the foundation pouring is completed, the pouring formwork is removed, and the poured foundation is cured until it is completely solidified.

[0029] The bottom of the grating screen is higher than the floor of the tunnel, and the height of the grating screen is one-third the height of the transport vehicle's tires.

[0030] As can be seen from the above technical solution, the underground mine chute screen construction method provided by the present invention involves backfilling the chute before screen construction, allowing construction workers to construct the screen in an open space at a preset height, thus avoiding high-altitude operations and improving construction safety; the double-layer screens are welded together to form an integral structure, making the overall structure of the screens firm and reliable; the double-layer screens are installed first, followed by centralized foundation pouring, which eliminates the restriction of pre-pouring foundations on screen installation, simplifies the process, shortens the construction period, improves work efficiency, and thus saves construction costs.

[0031] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to encompass all such aspects and their equivalents. Attached Figure Description

[0032] Other objects and results of the invention will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings. In the drawings:

[0033] Figure 1 A flowchart illustrating the construction method of a screen in an underground mine chute according to an embodiment of the present invention;

[0034] Figure 2 This is a top view of the structure of the underground mine chute screen construction method according to an embodiment of the present invention.

[0035] Figure 3 for Figure 2 A schematic diagram of the AA-direction structure;

[0036] Figure 4 This is a top-view structural diagram of the screen construction using the traditional mine chute screen construction method.

[0037] Figure 5 This is a side view diagram of the structure when constructing a screen using the traditional mine chute screen construction method.

[0038] In the attached diagram, 1-chutes, 2-positioning I-beams, 3-first vertical fixing component, 4-lower square steel, 5-upper square steel, 6-foundation, 7-base plate.

[0039] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0040] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details.

[0041] In response to the aforementioned existing technologies regarding the construction methods of traditional mine chute screens, which involve pouring the foundation before installing the screen and the fact that the screen installation requires workers to work at height inside the hollow chute, there are problems such as being greatly constrained by construction conditions, having a long construction period, and having a high construction risk factor. Therefore, a new construction method for underground mine chute screens is proposed.

[0042] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0043] To illustrate the construction method of the underground mine chute screen provided by the present invention Figure 1 The flowchart of a method for constructing a screen in an underground mine chute according to an embodiment of the present invention is shown; Figure 2 The diagram shows a top view of the screen being constructed using the underground mine chute screen construction method of this invention. Figure 3It shows Figure 2 AA-shaped structure; Figure 4 The diagram shows the top view of the screen during construction using the traditional mine chute screen construction method. Figure 5 The diagram shows the side view of the screen during construction using the traditional mine chute screen construction method.

[0044] like Figures 1 to 5 As shown in the figure, the construction method for underground mine chute screens provided by the present invention includes the following steps:

[0045] S1. Backfilling is carried out on chute 1 so that the gap between the top surface of the backfill and the opening of chute 1 reaches the preset height.

[0046] S2. Using the open ceiling as the construction space for the grid screen, positioning I-beams 2 are installed at both opposite ends of the wellhead of the chute 1. Both ends of the positioning I-beams 2 are fixed to the outside of the chute 1 by the first vertical fixing member 3.

[0047] S3. Install the lower square steel 4 between the positioning I-beams 2 at both ends of the wellhead. The two ends of the lower square steel 4 are respectively fixed to the outside of the chute 1 by the second vertical fixing member.

[0048] S4. An upper square steel 5 is erected above the lower square steel 4 in a cross pattern. The two ends of the upper square steel 5 are fixed to the outside of the chute 1 by the third vertical fixing member. The upper square steel 5 and the lower square steel 4 are welded together with the connecting member to form an integral structure, thus obtaining the grid screen to be poured. The hole formed by the intersection of the upper square steel 5 and the lower square steel 4 is used as the grid screen hole.

[0049] S5. Install the casting template on the outside of the screen to be cast, and tie and fix the end of the screen to be cast to the casting template so that the screen to be cast is fixed in the middle of the casting template. Use the casting template and the outer wall of the chute 1 as the foundation casting space.

[0050] S6. Remove the positioning I-beam 2 and carry out foundation pouring construction in the foundation pouring space. After the poured foundation 6 has solidified, complete the grid screen construction of the chute.

[0051] The structures such as the open ceiling, the second vertical fixing component, the third vertical fixing component, the connector, and the casting template are not shown in the attached drawings. Their positions in the technical solution can be understood based on the description of them in the preceding and following steps.

[0052] By backfilling the chute 1 before constructing the grid screen, construction workers can construct the grid screen in the pre-set height of the open ceiling, avoiding high-altitude operations and improving construction safety. The double-layer grid screens are welded together to form an integrated structure, making the overall structure of the grid screen firm and reliable. The method of installing the double-layer grid screens first and then pouring the foundation 6 centrally eliminates the restriction of pouring the foundation first, simplifies the process, shortens the construction period, improves work efficiency, and thus saves construction costs.

[0053] As a preferred embodiment of the present invention, backfilling the chute 1 to achieve a predetermined height in the void formed between the top surface of the backfill and the opening of the chute 1 includes:

[0054] Construct a vehicle blocking facility on the outside of the wellhead of chute 1 in the transport direction, use transport vehicles to transport slag and stone, and block the truck bed of the transport vehicle to unload the slag and stone in the truck bed into the interior of chute 1.

[0055] The gap between the backfill surface of the slag and stone inside the chute 1 and the opening of the chute 1 is made to reach the preset height.

[0056] To ensure the safety of the ore pass screen construction and reduce high-altitude work, ore pass 1 is backfilled with slag. Generally, ore pass 1 is constructed at the bottom of the receiving roadway, meaning its opening is located on the roadway floor 7. The ore pass extends downwards to transport the ore out of the roadway. A vehicle-stopping device is constructed on the outside of the ore pass opening in the transport direction to prevent vehicles transporting backfilled slag from unloading. Backfilling is completed when the slag backfill surface inside ore pass 1 reaches the preset height from the opening, and subsequent screen construction begins.

[0057] As a preferred embodiment of the present invention, the construction vehicle blocking facility includes:

[0058] A wheel-stop channel steel is installed on the outside of the shaft opening of chute 1 in the transport direction. Both ends of the wheel-stop channel steel are fixed to the top surface of the roadway by round steel anchor rods.

[0059] A 6000mm long, 20a channel steel is used as a vehicle-stopping channel steel above the roadway floor 7. Both ends of the channel steel are fixed to the roadway floor using 36mm diameter, 1600mm long round steel anchor rods. This allows transport vehicles to unload slag into the chute 1. The channel steel type, length, and round steel anchor rod parameters mentioned above are preferred options; however, specific settings can be made according to actual needs, and no particular limitation is made here. The vehicle-stopping facility can be removed after slag backfilling is completed.

[0060] As a preferred embodiment of the present invention, before using a transport vehicle to transport slag and using a vehicle-stopping device to block the truck bed of the transport vehicle so as to unload the slag in the truck bed into the chute 1, the method further includes:

[0061] At least two layers of geotextile fabric are laid around the opening of chute 1 so that transport vehicles can stop on the geotextile fabric for unloading of slag and stone. Laying geotextile fabric can help prevent slurry from flowing into the chute and absorb water.

[0062] As a preferred embodiment of the present invention, the preset height is 1.5 meters to 1.6 meters. That is, the height of the open ceiling or the height of the backfill is 1.5 meters to 1.6 meters, which is used for construction personnel to carry out grid screening construction in this space. The preset height can be determined according to the actual height of the construction personnel during construction to avoid construction personnel working at height and posing safety hazards.

[0063] As a preferred embodiment of the present invention, the first vertical fixing member 3 is a round steel anchor rod; and / or, the second vertical fixing member is a round steel anchor rod; and / or, the third vertical fixing member is a round steel anchor rod. The first vertical fixing member 3, the second vertical fixing member, and the third vertical fixing member are all preferably round steel anchor rods with a diameter of 36 mm and a length of 1600 mm. Their function is to fix the two ends of the positioning I-beam 2, the two ends of the lower square steel 4, and the two ends of the upper square steel 5 to the roadway outside the chute 1, respectively. That is, the end of the grid screen formed by the upper square steel 4 and the lower square steel 5 is wider than the end of the chute 1. Compared with the existing traditional grid screen construction, it is not necessary to add steel plates to the ends of the grid screen, i.e., the upper and lower square steels, to fix the grid screen, simplifying the construction process and shortening the construction period. During installation, two positioning I-beams 2 (model 20a, 4000mm long) are installed on both sides of the flat base plate 7. Each section is secured with two φ36mm diameter, 1600mm long round steel anchor rods. The positioning I-beams 2 primarily facilitate the installation, leveling, and reinforcement of the square steel. The length of the positioning I-beams 2 is slightly shorter than that of the lower square steel 4 and the upper square steel 5.

[0064] In a preferred embodiment of the present invention, the lower square steel 4 is perpendicular to the transport direction; the upper square steel 5 is parallel to the transport direction. To facilitate the later use of the chute 1, the screen is divided into two layers: the lower square steel 4 is perpendicular to the vehicle entry direction (i.e., the transport direction), and the upper square steel 5 is parallel to the vehicle entry direction. Both ends of the upper square steel 4 and the lower square steel 5 are fixed with round steel anchors with a diameter of φ36mm and a length of 1600mm.

[0065] In a preferred embodiment of the present invention, the upper square steel 5 and the lower square steel 4 are welded and fixed together as an integral structure using connectors, resulting in a grid screen to be cast, comprising:

[0066] A right-angled triangular connector is placed between the upper square steel 5 and the lower square steel 4;

[0067] The two right-angled sides of the right-angled triangular connector are welded to the top surface of the lower square steel 4 and the side surface of the upper square steel 5, respectively, so that the upper square steel 5 and the lower square steel 4 form an integral structure. The thickness of the right-angled triangular connector is preferably 40mm. The upper square steel 5 and the lower square steel 4 are stacked perpendicularly, with the right-angled triangular connector placed on one side of the upper square steel 5, and its bottom resting on the top surface of the lower square steel 4. Welding then forms a grid structure with rectangular or square sieve holes between the upper and lower square steel 5 and the lower square steel 4.

[0068] In a preferred embodiment of the present invention, the casting template is a wooden template. During foundation pouring, wooden templates are used for support. These templates are cut to the required specifications by a cutter. The wooden templates are tightly connected and fixed to the wooden boards with steel nails. The wooden templates are located outside the chute 1, with their lower ends inserted into the bottom slab of the tunnel. The screen is fixed above the chute 1 by pouring the foundation. When installing the casting template, reinforcing bars are tied. Vertical and horizontal reinforcing bars are made of 16mm diameter threaded steel, and 6mm diameter threaded steel is used as tie bars for internal adjustment and reinforcement of the wooden template. The binding length of the reinforcing bars is 35d. The ends of the reinforcing bars are welded to square steel or fixed anchor rods. This fixes the screen to be poured in the middle of the wooden template.

[0069] In a preferred embodiment of the present invention, after the positioning I-beam 2 is removed and the foundation pouring space is constructed, and the poured foundation 6 has solidified, the screen construction of the chute 1 is completed.

[0070] The foundation pouring construction uses concrete as the pouring material. After the concrete is mixed by the JS-350 self-falling mixer, it is discharged into the chute and flows into the foundation pouring space. When pouring concrete, it is strictly forbidden to use tools to knock on the support and fixed formwork. The concrete must be mixed evenly, the pouring surface must be flat, and it must be compacted after pouring.

[0071] After the foundation pouring is completed, the pouring formwork is removed, and the poured foundation 6 is cured until the foundation is completely solidified;

[0072] The bottom of the screen in chute 1 is higher than the floor slab 7 of the tunnel, and the height of the screen is one-third the height of the transport vehicle's tires. The chute screen can also serve as a vehicle barrier or a water barrier.

[0073] After construction, when using the sluice gate, debris is strictly prohibited from entering sluice gate 1. The slag must be kept dry before being placed into the gate, and water must not be allowed to enter. Proper management of the construction water at the wellhead of sluice gate 1 is essential; other water sources are strictly prohibited from entering sluice gate 1. During concrete pouring, the formwork must be tightly supported, and a layer of sponge and a layer of geotextile should be laid on the bottom slag surface to prevent grout leakage and absorb water. Except for water control during concrete pouring, no other water should flow into sluice gate 1. The slag backfilling material in sluice gate 1 must meet the block size requirements, not exceeding 300×300mm. After the sluice gate foundation construction is completed, a portion of the sluice gate should be emptied promptly and systematically to prevent sluice gate compaction.

[0074] As can be seen from the above specific embodiments, the underground mine chute screen construction method provided by the present invention involves backfilling the chute before screen construction, allowing construction workers to construct the screen in an open space at a preset height, thus avoiding high-altitude operations and improving construction safety; the double-layer screens are welded together to form an integral structure, making the overall structure of the screens firm and reliable; the method of installing the double-layer screens first and then pouring the foundation centrally eliminates the restriction of pre-pouring the foundation on the screen installation, simplifies the process, shortens the construction period, improves work efficiency, and thus saves construction costs.

[0075] The method for constructing a screen in an underground mine chute according to the present invention has been described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various modifications can be made to the method for constructing a screen in an underground mine chute according to the present invention without departing from the scope of the invention. Therefore, the scope of protection of the present invention should be determined by the contents of the appended claims.

Claims

1. A method of constructing a drawpoint screen in an underground mine, characterised by, Includes the following steps: S1. Backfill the chute so that the gap between the top surface of the backfill and the opening of the chute reaches a preset height. S2. Using the open ceiling as the construction space for the grid screen, positioning I-beams are installed at both opposite ends of the wellhead of the chute, and both ends of the positioning I-beams are fixed to the outside of the chute by the first vertical fixing member. S3. Install a lower square steel between the positioning I-beams located at both ends of the wellhead, and fix both ends of the lower square steel to the outside of the chute by the second vertical fixing member. S4. An upper layer of square steel is erected crosswise above the lower layer of square steel. The two ends of the upper layer of square steel are respectively fixed to the outside of the chute by a third vertical fixing member. The upper layer of square steel and the lower layer of square steel are welded and fixed together as a whole structure using connectors to obtain the grid screen to be poured. The hole formed by the intersection of the upper layer of square steel and the lower layer of square steel is used as the grid screen hole. S5. Install a casting template on the outside of the screen to be cast, and tie and fix the end of the screen to be cast to the casting template so that the screen to be cast is fixed in the middle of the casting template, and use the casting template and the outer wall of the chute as the foundation casting space. S6. Remove the positioning I-beam and carry out foundation pouring construction in the foundation pouring space. After the poured foundation has solidified, complete the grid screen construction of the chute.

2. The method of claim 1, wherein, The backfilling of the chute, ensuring that the gap between the top of the backfill and the opening of the chute reaches a preset height, includes: Construct a vehicle blocking facility on the outside of the wellhead in the transport direction, use transport vehicles to transport slag and stone, and block the truck bed of the transport vehicle to unload the slag and stone in the truck bed into the interior of the well. The gap between the backfill surface of the slag and the wellhead of the chute is made to reach a preset height.

3. The method of claim 2, wherein, The construction vehicle blocking facilities include: A wheel-stop channel steel is installed on the outside of the wellhead in the transport direction, and both ends of the wheel-stop channel steel are fixed to the top surface of the roadway by round steel anchor rods.

4. The method of claim 2, wherein, Before the step of using a transport vehicle to transport slag and using the vehicle blocking facility to block the truck bed of the transport vehicle so as to unload the slag in the truck bed into the interior of the chute, the method further includes: At least two layers of geotextile are laid around the opening of the chute so that the transport vehicle can stop on the geotextile to unload the slag and stone.

5. The method of claim 1, wherein, The preset height is 1.5 meters to 1.6 meters.

6. The method for constructing a screen in an underground mine chute according to claim 1, characterized in that, The first vertical fixing component is a round steel anchor rod; and / or, The second vertical fixing component is a round steel anchor rod; and / or, The third vertical fixing component is a round steel anchor rod.

7. The method for constructing a screen in an underground mine chute according to claim 1, characterized in that, The lower square steel is perpendicular to the transport direction; The upper square steel is parallel to the transport direction.

8. A method of constructing an underground mine drawbell grate according to claim 7, characterised in that, The process of welding and fixing the upper and lower square steel layers together using connectors to form a single structure, resulting in the grating to be cast, includes: A right-angled triangular connector is placed between the upper square steel and the lower square steel. The two right-angled sides of the right-angled triangular connector are welded to the top surface of the lower square steel and the side surface of the upper square steel, respectively, so that the upper square steel and the lower square steel form an integral structure.

9. The method for constructing a screen in an underground mine chute according to claim 1, characterized in that, The casting template is a wooden template.

10. A method of construction of a drawbell grate according to claim 2 or 4, characterised in that, During the process of dismantling the positioning I-beams and constructing the foundation in the foundation pouring space, and after the foundation has solidified, the sieve construction of the chute is completed. The foundation pouring construction uses concrete as the pouring material; After the foundation pouring is completed, the pouring formwork is removed, and the poured foundation is cured until it is completely solidified. The bottom of the grating screen is higher than the floor of the tunnel, and the height of the grating screen is one-third the height of the transport vehicle's tires.

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