Construction method of underground metal mine rail unloading system

Abstract

The present application relates to a kind of underground metal mine rail unloading system construction method.Prospecting construction includes the construction of mine warehouse and unloading chamber construction in turn, reverse excavation guide adit excavation, unloading station bottom structure excavation, branch chute excavation and mine warehouse extension brush.Protection construction includes safety closed platform and reinforced concrete and rail support.The present application changes the mode of previous whole rail unloading system single sequence construction, fully utilizes reverse excavation guide adit and temporary closed operation platform, realizes rail unloading station bottom structure, branch chute, mine warehouse sub-department once excavation forming in vertical space range, segmented parallel operation support new idea, changes excavation sequence, construction safety closed platform and other measures, changes original rail unloading unloading system construction mutual restriction, operation space is limited, measures engineering is more complicated situation, greatly shortens construction period.

Description

Technical Field

[0001] This invention belongs to the field of mining technology and relates to a method for excavation and lining construction of an underground rail-mounted unloading system. Background Technology

[0002] The rail-mounted unloading system is the most important and challenging part of the entire mine infrastructure project, determining whether the mine can be put into production as quickly as possible. Traditionally, the construction method for rail-mounted unloading systems in underground metal mines typically involves a bottom-up reverse excavation of the guide tunnel, a top-down widening process, and a bottom-up sequential pouring of concrete. Its main drawbacks are: first, unidirectional sequential construction results in low efficiency and a long construction period; second, limited working space leads to significant safety hazards; and third, large-scale blasting makes it difficult to guarantee construction quality. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a construction method for a rail-guided unloading system in an underground metal mine, which realizes three-dimensional excavation and lining of the bottom structure of the rail-guided unloading station, branch chutes and ore bins in a single excavation and segmented parallel operation within the vertical space.

[0004] The technical solution of the present invention is as follows:

[0005] A construction method for a rail-guided unloading system in an underground metal mine includes the following steps:

[0006] I. Tunneling Construction

[0007] First, construct the vibratory ore feeder chamber and the unloading station diagonally above the vibratory ore feeder chamber. Guide the tunnel through the opening in the side wall of the vibratory ore feeder chamber, and excavate back to the predetermined position point of the unloading station according to the surveying traverse. Then, control the bedrock excavation in the following order.

[0008] (a) Construction of the ore bin and unloading chamber

[0009] The middle part of the ore bin is a cylindrical bin structure. The upper end of the cylindrical bin structure is a variable diameter section, which is used to connect with the bottom structure of the unloading station. The lower end of the cylindrical bin structure is a conical bottom structure, and the outer end of the bottom structure is connected to the vibrating ore feeder chamber. An unloading chamber is constructed located diagonally above the ore bin.

[0010] (ii) Reverse excavation of the guide tunnel

[0011] The reverse tunnel is excavated from the opening in the side wall of the vibratory ore feeder chamber;

[0012] (III) Excavation of the bottom structure of the unloading station

[0013] The upper opening of the bottom structure of the unloading station is connected to the unloading station, and the lower opening is connected to the variable diameter section of the ore bin.

[0014] (iv) Branch chute excavation

[0015] After the bottom structure of the unloading station is expanded and slabred, the top of the ore bin is sealed with a protective plate. The construction workers then construct a branch chute on the protective plate, so that the upper end of the branch chute is connected to the unloading chamber. After the blasting is completed, the protective plate is removed and the blasting operation is carried out.

[0016] (v) Expansion and cleaning of the mine bins;

[0017] II. Support Construction

[0018] (a) Construction of a safe enclosed platform

[0019] Anchor bolts and channel steel are used as the supporting frame, and steel plates are used as the closed cover to construct a safe closed platform; the safe closed platform is located at the lower opening of the bottom structure of the unloading station.

[0020] (II) Reinforced concrete and rail support:

[0021] Construction sequence: Simultaneously construct the reinforced concrete structure of the branch chute and the bottom structure of the mine bin, and install rail support; dismantle the safety enclosure platform; construct the reinforced concrete structure of the mine bin and install rail support; construct the reinforced concrete structure of the variable diameter section of the mine bin and install rail support; construct the reinforced concrete structure of the bottom structure of the unloading station and install rail support.

[0022] The positive effects of this invention are as follows:

[0023] This invention fully utilizes the reverse-excavation guide tunnel and the safety enclosed platform to achieve three-dimensional excavation and construction of the bottom structure of the rail unloading station, branch chutes, and ore bins within a vertical space, with segmented parallel operation and support. The safety enclosed platform of this invention creates two independent spaces, one above the other, for the branch chutes and the ore bins, enabling parallel operation of the branch chutes' pouring support and the ore bin's bottom structure support. This improves construction efficiency and shortens the construction cycle. Specifically, the full utilization of the reverse-excavation guide tunnel in this invention connects the entire rail unloading system from top to bottom, forming ventilation and slag removal channels. This creates the construction conditions for the layered and zoned blasting of the bottom structure of the upper unloading station, fundamentally solving the problems of difficult construction, low efficiency, and difficulty in controlling the specifications of large-area blasting operations, often resulting in over-excavation and under-excavation, in previous large-scale rail unloading station bottom structure blasting operations. The use of the safety enclosed platform in this invention divides the system engineering, with a vertical difference of nearly 30 meters and operating in the same narrow space, into two independent working spaces, providing material channels and working platforms for the branch chutes' support and top safety assurance for the ore bin's bottom structure support. The use of this platform provides the basic conditions for parallel operation of branch ore pass support and bottom structure support of the ore bin. On this basis, the upper unloading station and the lower vibrating ore feeder chamber are used to form two personnel and material channels, which reduces the construction operation height, reduces construction safety risks, and improves construction operation efficiency.

[0024] By applying this invention and utilizing the spatial layout of various parts of the rail-mounted unloading system, the No. 2 rail-mounted unloading system in the -1140m section of the Sanshandao Gold Mine achieved one-time excavation and forming of the bottom structure of the rail-mounted unloading station, branch chutes, and ore bins within the vertical space, as well as segmented parallel operation support. This enabled close integration of personnel movement, material hoisting, and the construction platform, effectively solving the safety issues of three-dimensional parallel and cross-construction in rail-mounted unloading systems. Compared with previous experience in constructing similar rail-mounted unloading systems, the tunneling period was shortened by approximately 20 days, the concrete pouring period by approximately 30 days, and the total construction period was shortened by approximately 50 days. Attached Figure Description

[0025] Figure 1 This is a construction sequence diagram of the unloading station, branch ore pass, and mine bin excavation in an embodiment of the present invention.

[0026] Figure 2 This is a construction sequence diagram of the unloading station, branch chute, and mine bunker concrete support in an embodiment of the present invention.

[0027] In the diagram, 1. Unloading station, 2. Bottom structure of unloading station, 3. Back-drilling guide tunnel, 4. Bottom structure of ore bin, 5. Vibrating ore feeder chamber, 6. Ore bin, 7. Ore bin variable diameter section, 8. Branch chute, 9. Unloading chamber, 10. Safety enclosed platform. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0029] I. Tunneling Construction

[0030] First, construct the -1170m vibratory ore feeder chamber 5 and the -1140m unloading station 1. A guide tunnel is created through an opening in the side wall of the -1170m vibratory ore feeder chamber 5. Following the survey traverse, the tunnel is reverse-excavated to the predetermined location of the unloading station 1. Then, bedrock excavation is controlled according to the following sequence: (e.g.) Figure 1 As shown.

[0031] (a) Construction of ore bin 6 and unloading chamber 9

[0032] The middle section of the ore bin 6 is a cylindrical bin structure. The upper end of the cylindrical bin structure is a variable-diameter section 7, which connects to the bottom structure 2 of the unloading station. The lower end of the cylindrical bin structure is a conical bottom structure 4, with the outer end of the bottom structure 4 connected to the vibrating ore discharge machine chamber 5. An unloading chamber 9 at a depth of 1136m is also being constructed.

[0033] (II) Excavation of the reverse guide tunnel 3

[0034] The reverse excavation guide tunnel 3 opens onto the side wall of the -1170m vibratory ore discharge machine chamber 5, with an opening width of 2.5m and a height of 3m, capable of accommodating a 2m³ loader for operation. The total height of the guide tunnel is 30.7m, with a diameter of φ1735mm, and the excavation volume is approximately 75m³. The reverse excavation guide tunnel 3 serves as an auxiliary excavation ore pass. Smooth blasting is required around the ore pass walls to control the wall profile. Nine blast holes are arranged around the perimeter, each approximately 2.0m deep, with a spacing of 607mm, according to the designed excavation outline. Five auxiliary blast holes are spaced 450mm apart, and four core holes are also included, for a total of eighteen blasting holes. The explosive used is No. 2 emulsion explosive, detonated by a detonating cord cluster connected to a non-electric half-second detonating detonator.

[0035] (III) Tunneling of the Bottom Structure of the Unloading Station

[0036] The bottom structure of the unloading station at the -1140m mid-section has an upper opening size of 28000mm × 5320mm, a lower opening size of 6330mm × 3830mm, a vertical height of 10941mm, and a bedrock excavation volume of 800m³. The blast hole layout is divided into three areas: the pilot tunnel central area, the double-sloping area, and the corbel side area. The bottom structure of unloading station 1 adopts a top-down, center-to-side excavation method, employing a "layer-by-layer peeling, step-by-step construction" approach. Due to the design characteristics of the bottom structure of unloading station 1, the cross-sectional dimensions vary with each excavation. Therefore, based on the excavation cross-section, measures such as "drilling more holes, using less explosives, and partial blasting" must be adopted to strengthen the control of the surrounding holes. Following the construction sequence of excavation at the bottom slope of the unloading station and excavation at the bottom corbel section of the unloading station, the unloading station slope area features vertically arranged holes at an 80-degree angle, extending from the edge of the reverse excavation guide tunnel (circulation hole depth 3900mm) to both ends (hole depth 965mm) in a block-like pattern. The vertical holes in the corbel section of the unloading station have a depth of 3400mm. From the center of the reverse excavation guide tunnel 3, holes are distributed in a trapezoidal shape to both sides (block-like, 3830mm wide, 2100mm long, 3900mm deep). In the central area 12 of the guide tunnel, two rows of holes are arranged vertically, with a 500mm distance from the edge of the guide tunnel to the first row of blast holes, a row spacing of 615mm, and a hole spacing of 400mm. The hole width in the left and right slope areas is 3830mm, and the hole length is 28600mm; the hole width in the corbel section is 1500mm, and the hole length is 21200mm. The surrounding boreholes are arranged according to the design outline, with a spacing of 500mm, and the spacing of the auxiliary boreholes is 600mm~750mm; the explosive is No. 2 emulsion explosive, and the detonating cord cluster is connected to a non-electric millisecond detonating detonator for initiation; the explosive is No. 2 emulsion explosive, and the detonating cord cluster is connected to a non-electric millisecond detonating detonator for initiation.

[0037] (iv) Branch chute 8 excavation

[0038] The unloading station branch chute 8 is designed to have a drilling volume of 160m³. After the bottom structure 2 of the unloading station is expanded and constructed, the upper opening of the ore bin 6 (i.e., the ore bin diameter-changing section 7) is sealed with a protective plate. Construction personnel then descend to this location to drill holes in the branch chute 8, connecting its upper end to the unloading chamber 9. After loading the blasting equipment, the protective plate is removed using the electric hoist of the unloading chamber 9 before blasting operations commence. The branch chute 8 has a rough width of 3000mm, a rough height of 3000mm, a length of 7888mm, and a surface area of ​​9.62㎡. The bottom dimensions of the branch chute 8 are a rough width of 3000mm, a rough height of 5500mm, a depth of 2500mm, and a surface area of ​​16.5㎡. Peripheral blast holes are arranged according to the design outline, with a spacing of 600mm, and auxiliary holes are spaced 600mm~750mm apart. The explosive used is No. 2 emulsion explosive, detonated by a detonating cord cluster connected to a non-electric millisecond detonating detonator.

[0039] (v) Expansion and cleaning of mine bin 6

[0040] The top of ore bin 6 connects to the bottom structure of unloading station 1, and the lower part is integrally cast with the side chamber walls of the -1170m crushing chamber, forming a circular shape. The entire structure is divided into three parts: the upper part is an eccentric variable-diameter section (square at the top, circular at the bottom, 6393mm × 3830mm / φ6268mm), with a height h=2000mm; the middle section is a cylindrical section, circular (raw diameter φ6268mm), with a height h=9759mm; and the lower part is the bottom structure 4 of the ore bin (irregular structure, square at the top, φ6269mm / 1650mm × 1750mm), with a height h=4439mm. The excavation volume of ore bin 6 is 360.6m³. Peripheral blast holes are arranged according to the design outline, with a spacing of 600mm, and auxiliary holes are spaced 600mm~750mm apart; the explosive is No. 2 emulsion explosive, detonated by a cluster of detonating cords connected to non-electric millisecond detonating detonators. The ore bin is then expanded and temporarily supported. Considering the safety of subsequent construction in the mine bunker, during the downward expansion process, two excavations and one support were carried out, mainly using anchor spraying or plain spraying for temporary support.

[0041] The rock drilling equipment used is a YT28 rock drill, equipped with a 40mm alloy steel drill bit and a 2.5m long drill rod, with a drilling depth of approximately 2.0m per blast. Slag removal is carried out using a 2m³ loader from chamber 5 of the vibratory ore feeder at -1170m and transported to the -1140m intermediate inclined chute. Ventilation is provided by a forced-flow ventilation system, with two 22kW counter-rotating fans installed at the head gate of the main shaft at -1170m, along with a φ600mm ventilation duct, to directly supply fresh air to the shaft working face.

[0042] II. Permanent Support Construction

[0043] (a) Construction of 10 safe enclosed platforms

[0044] According to the construction drawings of the safety enclosure platform 10, the anchoring positions were pre-marked inside the shaft rock wall using spray paint. Φ32mm threaded steel was selected as the anchor rods, and sixteen anchor rods were driven into the rock wall. Each anchor rod was 1500mm long, 1000mm deep, and 500mm protruded from the rock wall. Channel steel was used as the support frame, with five longitudinally arranged, each 2800mm long, and both ends of each beam welded and fixed to the exposed portion of the anchor rod. Three transversely arranged, each 3200mm long, were welded and fixed at the junctions of the transverse and longitudinal beams, and at both ends of the transverse beams to the anchor rods. Two 5mm thick steel plates, 2800mm × 1600mm in size, were used as the enclosure cover, with both ends of the steel plates welded and fixed to the overlapping parts of the transverse beams. The enclosure platform creates two independent spaces between the -1140m branch ore pass and the -1170m mine bin, enabling parallel construction of the branch ore pass support and the bottom structure of the mine bin. like Figure 2 As shown.

[0045] (II) Reinforced concrete and rail support:

[0046] Construction sequence: Simultaneously construct the reinforced concrete of branch chute 8 and bottom structure 4 of the mine bin, and install rail support; dismantle safety enclosure platform 10; construct reinforced concrete of mine bin 6 and install rail support; construct reinforced concrete of mine bin variable diameter section 7 and install rail support; construct reinforced concrete of bottom structure 2 of unloading station and install rail support, as follows... Figure 2 As shown.

[0047] Construction process: Erect scaffolding; install anchor bolts and tie reinforcing bars on the shaft sides from bottom to top; install annular grooves.

[0048] Steel; integral hanging rail; formwork installation; pouring.

[0049] The mixing plant is located on one side of unloading station 1. A material unloading platform is erected at the top of branch chute 8 at -1136m. Concrete is transferred to the chute's guide pipe via Ф159 plastic pipes (ash chute pipes) to pour the concrete for branch chute 8. Materials such as light rails, channel steel, and reinforcing bars used for pouring branch chute 8 are transported from unloading station 1 at -1140m to the work face. Reinforcing bar support specifications: 500mm thick reinforced concrete, double-layer reinforcement, transverse ring reinforcement Φ20@200mm, vertical reinforcement Φ16@200mm, tie bars Φ8@500*500, reinforcement layer spacing 300mm, total length of hooks at both ends of the reinforcement 12.5d, lap length 30d. First, the vertical reinforcement is tied and welded to the anchor rods installed on the chute wall. Then, the transverse reinforcement is tied. When tying upwards, the vertical reinforcement is lapped with the pre-reserved reinforcement below, and then tied upwards according to the design. Large components such as rails, channel steel, and large embedded parts are lifted and unloaded using an electric hoist at the unloading station. First, prepare the rails (38kg / m), channel steel rings, and anchoring hooks. The "7" shaped rail sections, channel steel rings, and anchoring hooks are prefabricated on the ground. Next, weld the channel steel rings. After the reinforcing bars are properly tied, weld the channel steel rings and anchoring hooks to the upper surface of the reinforcing bars according to the design positions. The channel steel rings and anchoring hooks must be strictly arranged according to the design and firmly welded to the reinforcing bars. After the channel steel rings are properly arranged and firmly welded, weld and hang the 38kg / m rails according to the design, and weld the anchoring hooks to the rails. After the rails are hung, strictly check whether the layout specifications meet the requirements and whether the welding quality meets the standards. After passing the inspection, formwork can be installed and poured. For the chute formwork, reinforced rails combined with wooden formwork (the wooden formwork is fixed between adjacent rails) are used to create the formwork. The steel strips are not removed after pouring. Formwork is installed and poured sequentially from bottom to top. The poured concrete thickness is 500mm, with a strength grade of C30. The empty space between the cast-in-place structure and the well wall must be completely filled with concrete.

Claims

1. A method of constructing a rail unloading system for an underground metal mine, characterised by It comprises the following steps: I. Excavation construction First, the construction of the vibrating ore pass chamber (5) and the unloading station (1) above the vibrating ore pass chamber (5) is carried out by opening a guide tunnel from the side wall of the vibrating ore pass chamber (5), excavating back to the predetermined position point of the unloading station (1) according to the surveying guide line, and then excavating the bedrock in the following order: (1) Construction of the ore bin (6) and the unloading chamber (9) The middle part of the ore bin (6) is a cylindrical bin body structure, the upper end of the cylindrical bin body structure is a variable-diameter section (7) of the ore bin, the upper end of the variable-diameter section (7) of the ore bin is used to connect with the bottom structure (2) of the unloading station, the lower end of the cylindrical bin body structure is a conical bottom structure (4) of the ore bin, and the outer end of the bottom structure (4) of the ore bin is connected with the vibrating ore pass chamber (5); and the unloading chamber (9) above the ore bin (6) is constructed; (2) Excavation of the back-excavated guide tunnel (3) The back-excavated guide tunnel (3) is excavated from the side wall opening of the vibrating ore pass chamber (5); (3) Excavation of the bottom structure (2) of the unloading station The upper opening of the bottom structure (2) of the unloading station is connected with the unloading station (1), and the lower opening is connected with the variable-diameter section (7) of the ore bin; (4) Excavation of the branch chute (8) After the expansion brushing of the bottom structure (2) of the unloading station is completed, the upper opening of the ore bin (6) is sealed with a protective plate, the branch chute (8) is constructed on the protective plate by the construction personnel, so that the upper end of the branch chute (8) is connected with the unloading chamber (9); after the completion of the gun installation, the protective plate is removed, and blasting operation is carried out again; (5) Expansion brushing of the ore bin (6); II. Support construction (1) Erection of the safety closed platform (10) The safety closed platform (10) is erected by using anchor rods and channel steel as support skeletons and steel plates as closed cover plates; the safety closed platform (10) is located at the lower opening position of the bottom structure (2) of the unloading station; (2) Steel reinforced concrete and rail support Construction sequence: simultaneously construct the steel reinforced concrete of the branch chute (8) and the bottom structure (4) of the ore bin, and hang rail support; remove the safety closed platform (10); construct the steel reinforced concrete of the ore bin (6) and hang rail support; construct the steel reinforced concrete of the variable-diameter section (7) of the ore bin and hang rail support; and construct the steel reinforced concrete of the bottom structure (2) of the unloading station and hang rail support.

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