A composite anchored steel strand mesh reinforcement structure for mine bunkers

Abstract

This utility model discloses a composite anchored steel strand mesh structure for mine bunker reinforcement. It includes a steel strand mesh structure fixed to the mine bunker structural substrate. The steel strand mesh structure is bonded to the original structural substrate with polymer cement mortar. The steel strand mesh structure is fixed to an anchor plate by anchors. The anchor includes a shell with a conical through-hole (larger at the top, smaller at the bottom). A clamping element for clamping the steel strands is inserted through the shell. The clamping element includes multiple conical clamping plates that can enclose the steel strands. A pusher is connected to the larger end of the shell to move the clamping element towards the smaller end, and a connecting seat with a flared hole is also provided. This utility model uses a reliable and corrosion-resistant anchor to connect the steel strand mesh reinforcement system to the mine bunker structural substrate. Applying the steel strand mesh structure to mine bunker reinforcement significantly improves repair efficiency.

Description

Technical Field

[0001] This utility model relates to the field of concrete structure reinforcement technology, specifically to a structure for reinforcing a mine silo using steel strand mesh. Background Technology

[0002] As a key facility in a mine, the ore bin is primarily used for the temporary storage and transfer of ore. The old vertical shaft ore bin at the Jiaojia Gold Mine is part of the second phase of the mine's renovation project. It was designed by the Beijing Nonferrous Metallurgical Design and Research Institute and constructed by the Shaft and Tunnel Engineering Company of China Nonferrous Metals Tenth Construction Company. Built in 1986, the ore bin uses a reinforced concrete frame silo structure. Due to years of exposure to harsh working conditions, such as continuous impact during ore unloading and corrosion from chloride-containing moisture, the structural matrix has suffered damage. Simultaneously, vibrations from mine car operations exacerbate the damage, allowing corrosive media to further penetrate. Furthermore, issues such as low-grade concrete and a thin protective layer in the early design contribute to structural safety hazards.

[0003] Chinese invention patent application CN117266605A discloses a silo reinforcement method using shotcrete and steel strands. This method involves temporarily reinforcing the silo's outer wall with circumferential steel strips and prestressed steel strands, followed by laying a reinforcing mesh and then shotcreting to form a permanent reinforcement layer. However, this solution has significant drawbacks: the use of steel strips and reinforcing mesh combined with two layers of concrete, each 50–60 mm thick, results in a large material consumption and a significant increase in self-weight, exacerbating the foundation load and being particularly detrimental to the vibration environment of mines. Furthermore, the thick concrete reinforcement layer requires a long curing period, making it unsuitable for scenarios requiring rapid repair.

[0004] If steel strand mesh combined with polymer mortar is directly used to reinforce the mine bin, vibration and material impact can easily cause micro-displacement of the clamps, resulting in a decrease in anchoring force. Traditional clamp-type anchors cannot adapt to the high stress and dynamic load environment of mine bin reinforcement, and existing anchors cannot maintain stable anchoring force under vibration loads. Therefore, there is an urgent need for an anchoring system that can simultaneously solve the notch effect, resist micro-displacement, and have long-term corrosion resistance to ensure the reliable application of steel strand mesh reinforcement technology in the harsh environment of mine bins. Utility Model Content

[0005] This utility model proposes a composite anchored steel strand mesh reinforcement structure for mine bunkers, the purpose of which is: 1. To address the problems of large material consumption, thick reinforcement layers, and heavy weight in existing mine bunker reinforcement methods; 2. To solve the problem of localized damage to the steel strands that exists in traditional clamp-type anchors when using steel strand mesh for reinforcement.

[0006] The technical solution of this utility model is as follows: A composite anchored steel strand mesh mine bunker reinforcement structure includes a steel strand mesh structure fixed to the mine bunker structural base. The steel strand mesh structure is bonded to the structural base with polymer cement mortar. It also includes an anchor plate fixed to the mine bunker structural base by expansion bolts. The ends of the steel strands in the steel strand mesh structure are fixed to the anchor plate by anchors. The anchor includes a shell with a conical through-hole (larger at the top, smaller at the bottom) and a clamping member for clamping the steel strands passing through it. The larger end of the shell is connected to a pushing member for moving the clamping member towards the smaller end. The bottom of the pushing member has a protrusion that can extend into the shell, and the center of the pushing member has a through-hole for the steel strands to pass through. The lower part of the shell has a step to limit the shell's passage through the anchor plate. A threaded connection section passes through the anchor plate and is connected to a connecting seat.

[0007] Furthermore, the clips are coaxially arranged with the outer shell, and there are three to four clips.

[0008] Furthermore, the inner wall of the clip is provided with internal teeth, and the spacing of the internal teeth gradually decreases from the large end to the small end.

[0009] Furthermore, the inner tooth shape is a composite of arc and serration, with the top of the inner tooth being an arc surface with a radius of 1 mm, and the inner tooth being hook-shaped, with the upper inclined surface having a smaller inclination angle than the lower inclined surface.

[0010] Furthermore, the connecting seat has a flared hole that is smaller at the top and larger at the bottom. The diameter of the smaller opening of the flared hole is less than or equal to the inner diameter of the bottom of the clamping member, which is used to ensure the accurate positioning of the steel strand and prevent it from being clamped eccentrically.

[0011] Furthermore, the anchor plate, outer shell, propeller, connecting seat and clamping member are all coated with an anti-corrosion layer, and the inner tooth contact area of ​​the clamping piece is additionally sprayed with a polytetrafluoroethylene anti-friction coating to reduce frictional damage with the steel strand and improve corrosion resistance.

[0012] Compared with the prior art, the present invention has the following advantages: (1) This utility model significantly improves the compressive and shear bearing capacity of the mine bunker by replacing the traditional steel mesh with a high-strength steel strand mesh and applying prestress through tensioning the steel strands, thus solving the problem of reduced bearing capacity of the original structural base due to steel corrosion. Simultaneously, combined with a thin layer of polymer mortar (total thickness ≤50mm), the material usage is greatly reduced. In the example, 15 tons of steel reinforcement and 12 cubic meters of concrete are saved, avoiding a significant increase in structural self-weight and reducing the foundation burden. The construction process eliminates the need for steel plate fixing and multi-layer concrete spraying, reducing the construction period from 24 days to 14 days, enabling rapid resumption of production, directly saving 82,200 yuan in costs, and indirectly generating 910,000 yuan in economic benefits.

[0013] (2) This utility model sets up a clip with two segments of unequal tooth spacing, combined with a circular arc-sawtooth composite tooth shape, with a top R=1mm circular arc, which effectively disperses contact stress, weakens the "cutting effect", and reduces damage to the steel strand; the barbed internal tooth, with an upper oblique angle < lower oblique angle, combined with a tapered hole self-locking, resists the micro-displacement of the clip under vibration impact, and the anchoring force is not less than 95% of the breaking force of the steel strand.

[0014] (3) This utility model significantly improves corrosion resistance by spraying a polytetrafluoroethylene anti-corrosion layer on each component of the anchor and an additional polytetrafluoroethylene friction-reducing layer on the inner tooth area of ​​the wedge; the polymer mortar has high resistance to chloride ion penetration and strong adhesion, protects the steel strand and forms an integral whole with the matrix, and extends the service life of the structure.

[0015] (4) This utility model ensures accurate positioning of the steel strand by setting a connecting seat with a horn hole and a pusher with a center hole in coordination, and prevents stress concentration caused by eccentric clamping.

[0016] (5) In the embodiment of the prefabricated module, the steel strand mesh and polymer mortar are prefabricated in the factory and quickly assembled on site by anchor plates, which further shortens the construction period and reduces on-site wet work. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the steel strand mesh mine bin reinforcement structure in an embodiment of this utility model; Figure 2 This is a cross-sectional view of the reinforced structural substrate according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the anchoring device in an embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the fixing method of the steel strand mesh in an embodiment of this utility model; Figure 5 This is a schematic diagram of the connection node between the anchor and the anchor plate in an embodiment of this utility model; Figure 6 for Figure 5 Sectional view of AA.

[0018] Explanation of reference numerals in the attached figures: 1. Structural base; 21. First anchor plate; 22. Second anchor plate; 3. Fixing bolt; 4. Anchor; 41. Outer shell; 411. External hexagonal; 412. Threaded section; 42. Pushing component; 43. Clamping component; 44. Connecting seat; 441. Trumpet hole; 5. Steel strand mesh structure; 6. U-shaped clamp; 7. Reinforcing layer. Detailed Implementation

[0019] The technical solution and effects of this utility model will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0020] like Figures 1 to 4 As shown, a composite anchored steel strand mesh mine bunker reinforcement structure includes a steel strand mesh structure 5 fixed on the mine bunker structure base 1. The steel strand mesh structure 5 is bonded to the structure base 1 with polymer cement mortar to form a reinforcement structure.

[0021] The steel strand mesh structure 5 includes vertical steel strands and horizontal steel strands, wherein the vertically arranged steel strands are load-bearing components and are located on the side close to the structural base 1, while the horizontal steel strands are located outside the vertical steel strands.

[0022] The vertical steel strands are arranged at 100mm intervals on the inner side near the structural base 1, while the horizontal steel strands are arranged at 150mm intervals on the outer side of the vertical steel strands. The intersections of the two are locked together by U-shaped clamps 6. After installation, the mesh 5 forms a 5-10mm gap with the mine bin base. The ends of the steel strands are equipped with an anti-slip structure, which is made of compatible iron wire wound with a winding length of 3-5 times the diameter of the steel strand and an iron wire diameter of 1-1.5mm, with 5 tight turns every 10mm.

[0023] The steel strand mesh structure 5 is fixed to anchor plates at both ends, and the anchor plates are fixed to the mine bin structure base 1 by expansion bolts. The upper anchor plate is the first anchor plate 21, and the lower anchor plate is the second anchor plate 22. The anchor plate includes a first side for connecting to the structure base 1 and a second side for fixing the anchor head, with the first side perpendicular to the second side. The vertical steel strands are fixed to the second side of the anchor plate by anchors 4.

[0024] Combination Figure 5 and Figure 6As shown, the anchor 4 includes a cylindrical outer shell 41. A threaded connection section is provided at one end of the outer shell 41 near the anchoring side. A through hole is formed inside the threaded connection section of the outer shell 41. A conical through hole with its smaller end facing the anchoring side is formed near the anchoring side, and the inner diameter of the smaller end of the conical through hole is slightly smaller than the diameter of the steel strand. A clamping member 43 passes through the outer shell 41. A pushing member 42 is connected to the larger end of the outer shell 41 for pushing the clamping member 43 towards the smaller end. The bottom of the pushing member 42 has a protrusion that can extend into the interior of the outer shell 41, and its center has a through hole for the steel strand to pass through. A threaded connection section is provided at the lower end of the outer shell 41. A step is provided at the upper end of the threaded connection section to limit the outer shell 41 from extending beyond the anchoring plate's limit position. After passing through the anchoring plate, the threaded connection section is connected to a connecting seat 44. The connecting seat 44 has a flared hole 441, which is smaller at the top and larger at the bottom. The smaller diameter of the flared hole 441 is less than or equal to the inner diameter of the bottom of the clamping member 43. This is used to ensure the precise positioning of the steel strand and prevent it from being clamped eccentrically. The ends of the steel strand are wound with iron wire to create radial pressure, increasing the friction with the anchor 4 and reducing slippage of the wire rope. The winding length is 3-5 times the diameter of the steel strand, the iron wire diameter is 1-1.5 mm, and the material must be compatible with the steel strand to avoid electrochemical corrosion. There are 5 turns for every 10 mm of length to ensure uniform stress.

[0025] The clamping member 43 includes three to four clamping pieces for clamping the steel strand. The clamping pieces are coaxially arranged with the outer shell 41, forming a conical cylinder. The inner wall of the clamping piece is provided with internal teeth for clamping the steel strand. The internal teeth include two ends with unequal tooth pitches, with a tooth pitch of 3 mm at the larger end and 1.5 mm at the smaller end. The tooth shape is a combination of arc and sawtooth. The top of the internal teeth is an arc surface with a radius of 1 mm. The internal teeth are barbed, and the inclination angle of the upper inclined surface is smaller than that of the lower inclined surface, so as to increase the contact area between the clamping member 43 and the steel strand, and to distribute stress to prevent the anchor head end from cutting the steel strand.

[0026] The anchor plate has regular polygonal through holes, and the lower part of the anchor 4 has an external hexagon 411 that matches the hexagonal through holes. The two work together to prevent relative rotation between the anchor 4 and the anchor plate. The center distance of the through holes is determined so that a gap of 5 to 10 mm is left between the mesh and the mine bunker structure base 1 after installation.

[0027] Furthermore, to enhance the corrosion resistance of the anchor 4, the anchor plate, outer shell 41, pusher 42, connecting seat 44, and clamping member 43 are all coated with a polytetrafluoroethylene (PTFE) anti-corrosion layer. Before applying the anti-corrosion layer, the rusted steel components are first derusted. An additional PTFE anti-friction coating is applied to the inner tooth contact area of ​​the clamping piece to reduce frictional damage with the steel strand and improve corrosion resistance.

[0028] During construction, after the steel strand mesh is fixed by anchor plates and bolts, a special interface agent needs to be prepared and evenly sprayed or applied to the surface of the reinforced components. Then, a Class I polymer mortar with strong penetration is sprayed to form a reinforcement layer 7 on the outside of the structural substrate 1, so that the old and new structures become one and jointly bear the bending moment and shear force under the load.

[0029] The following describes the construction process for actively reinforcing the outer wall of the mine bunker after concrete spalling and steel reinforcement corrosion, using steel strand mesh, polymer cement mortar, and anchor 4 in this embodiment: First, the damaged areas of the mine bunker that need reinforcement are roughened to a depth of 10 mm or more, without damaging the original reinforcement of the base material. Loose concrete and dust are removed, and the area is then rinsed with a high-pressure water gun and dried.

[0030] Then, the upper first anchor plate 21 and the lower second anchor plate 22 are fixed to the mine bin structure base 1 with expansion bolts and leveled. Next, the vertical steel strands of the steel strand mesh are passed through the flared holes 441 of the anchor 4 connecting seat 44 and into the clamping member 43, fixing the steel strand mesh to the anchor plates. The spacing of the steel strands can be determined based on the vibration intensity of the area where the mine bin is located; for example, they can be denser in areas with strong vibration, such as the unloading port.

[0031] Adjusting the upper anchor 4 causes the steel strand to move along the conical hole of the outer shell 41, gradually engaging the inner teeth of the variable-pitch clamp with the steel strand. The rotating propeller 42 pushes the clamping assembly 43 towards the smaller end, simultaneously moving towards the axis under the action of the conical hole wall, gradually engaging with the steel strand. Then, the steel strand is tensioned from below to the design prestress, reaching 70% to 80% of the standard tensile strength of the steel strand. The lower anchor 4 is then adjusted to ensure a tight connection with the second anchor plate 22.

[0032] After the steel strand mesh is fixed, spray or apply polymer cement mortar to the substrate. The polymer cement mortar needs to be applied in three layers using a cross-hatching method, meaning the first and second layers are applied at 90-degree angles to enhance adhesion and coverage. The first layer is approximately 15mm thick, flush with the steel strands, to ensure the mesh adheres to the substrate. The second layer is 25mm thick. Each coat should be thin and even, avoiding localized buildup. Allow at least 5 hours between coats to ensure drying. The third layer is 10mm thick.

[0033] Cut off the excess steel strands exposed on anchor 4 and seal the gap between anchor 4 and the mortar base with epoxy mortar.

[0034] To further shorten the construction period, this utility model can also calculate the specifications and dimensions of the steel strands according to the size of the mine bin, use steel strand mesh and polymer cement mortar to prefabricate and cure the precast blocks in the factory, and then assemble them on site.

[0035] It should be noted that, as will be apparent to those skilled in the art, this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. The scope of this utility model is defined by the claims rather than the foregoing description.

Claims

1. A composite anchored steel strand mesh mine bunker reinforcement structure, comprising a steel strand mesh structure (5) fixed to a mine bunker structural base (1), wherein the steel strand mesh structure (5) is bonded to the structural base (1) by polymer cement mortar, and further comprising an anchor plate fixed to the mine bunker structural base (1) by expansion bolts, wherein the ends of the steel strands of the steel strand mesh structure (5) are fixed to the anchor plate by anchors (4), characterized in that: The anchor (4) includes a housing (41), which has a conical through hole that is larger at the top and smaller at the bottom. A clamping member (43) for clamping steel strands is provided inside the housing (41). A pusher (42) for pushing the clamping member (43) to move towards the smaller end is connected to the larger end of the housing (41). The bottom of the pusher (42) has a protrusion that can extend into the housing (41), and a through hole for the steel strand to pass through is provided in the center of the pusher (42). The lower part of the outer shell (41) is provided with a step for limiting the outer shell (41) from passing through the limit position of the anchor plate, and the threaded connection section is connected to the connecting seat (44) after passing through the anchor plate.

2. The steel strand mesh bin reinforcement structure of claim 1, wherein: The clamping member (43) is coaxially arranged with the outer shell (41), and the clamping member (43) includes three to four clamping pieces.

3. The steel strand mesh bin reinforcement structure of claim 2, wherein: The inner wall of the clip is provided with internal teeth, and the spacing of the internal teeth gradually decreases from the large end to the small end.

4. The steel strand mesh bin reinforcement structure of claim 3, wherein: The inner tooth profile is a composite of arc and serration. The top of the inner tooth is an arc surface with a radius of 1 mm. The inner tooth is hook-shaped, and the inclination angle of its upper bevel is smaller than that of the lower bevel.

5. The steel strand mesh bin reinforcement structure of claim 1, wherein: The connecting seat (44) has a horn hole (441) that is smaller at the top and larger at the bottom. The diameter of the small opening of the horn hole (441) is less than or equal to the inner diameter of the bottom of the clamping member (43) to ensure the accurate positioning of the steel strand and prevent it from being clamped eccentrically.

6. A steel strand mesh ore bin reinforcing structure as claimed in any one of claims 1 to 5, characterised in that: The anchor plate, outer shell (41), pusher (42), connecting seat (44) and clamping member (43) are all coated with anti-corrosion layer. The inner tooth contact area of ​​the clamp is additionally sprayed with polytetrafluoroethylene anti-friction coating to reduce friction damage with the steel strand and improve corrosion resistance.

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