Prefabricated wall unit and wall structure for gob-side entry retaining

Abstract

The present application relates to the technical field of coal mining, and provides an assembled gob-side entry retaining wall unit and a wall structure, the wall unit comprising: an outer shell, the inner wall of which defines a pouring cavity; a top sealing plate arranged in the pouring cavity and fixedly connected with the outer shell; in the longitudinal direction of the outer shell, the top sealing plate separates the pouring cavity into a prefabrication cavity and a top sealing cavity, the end of the top sealing cavity away from the prefabrication cavity being open; the prefabrication cavity is used for pouring concrete in the prefabrication stage of the wall unit, and the top sealing cavity is used for pouring high-strength concrete in the top sealing stage; a shear connector arranged in the pouring cavity and fixedly connected with the outer shell, used for connecting the outer shell and the concrete in the pouring cavity. In this way, prefabricated assembly of the support structure, high-load synergy, rapid construction and cost optimization can be achieved, and the support requirements of the rapidly advancing working face can be better matched.

Description

Technical Field

[0001] This invention relates to the field of coal mining technology, and in particular to a prefabricated goaf retaining wall unit and wall structure. Background Technology

[0002] With the deepening of global energy structure transformation and the "dual carbon" goal, coal's strategic position as my country's basic energy source remains solid. Meanwhile, the industry's requirements for resource recovery rate, mining efficiency, and green safety levels continue to upgrade. Gob-side entry and pillarless mining technology, as one of the core technologies for the transformation and upgrading of the coal industry, can effectively recover coal pillar resources left over from traditional mining, increasing the resource recovery rate by more than 10%. It also reduces the amount of roadway excavation work and alleviates the tension between mining and tunneling operations. It has been widely used in mining scenarios of medium and thick coal seams and below in national-level coal bases such as Inner Mongolia-Shaanxi and Shanxi-Shaanxi. The Inner Mongolia-Shaanxi mining area, as one of the regions with the largest coal production and highest mining intensity in my country, places extremely high demands on the adaptability and reliability of gob-side entry and exit technology.

[0003] While current mainstream technologies such as flexible concrete walls for roadway retention along the goaf offer the advantage of simple support structures, they reveal numerous unavoidable shortcomings and generate a series of chain problems when adapting to the rapid advancement requirements of most working faces in the Inner Mongolia and Shaanxi mining areas, which exceed 10m / d and in some areas reach 20m / d. Firstly, the roadway operation requires the on-site pouring of a large amount of concrete, which results in a long construction period, low construction efficiency, and a large investment of manpower. Often, the number of workers in a single shift exceeds the national limit, leading to not only high construction costs but also a huge amount of roadway maintenance work in the later stages.

[0004] Secondly, the material consumption is large and the economy is poor: the consumption of concrete and consumables (such as disposable formwork, flexible membrane bags, etc.) is high, the total material cost remains high, and the economic rationality of the technology application is insufficient.

[0005] Third, the support performance cannot withstand complex mining pressure: Under rapid advance conditions, the span of the overlying strata fractures increases sharply, the stress of the surrounding rock in the roadway is highly concentrated, and the mining pressure is extremely intense. However, the roadway support structure of traditional technology has inherent performance defects. The ordinary silicate cement concrete used has slow early strength growth. When the unit support is removed after 6 to 12 days, the strength only reaches 55% to 65% of the final setting strength. Even if an early strength agent is added or the concrete grade is increased, it is still difficult to solve the core problem that the strength improvement lags behind the mining progress and cannot withstand dynamic pressure impact.

[0006] Given the above problems, how to solve the issues of insufficient load-bearing capacity, poor collaborative workability, and lagging strength improvement of traditional roadway retention technology, while taking into account construction efficiency, construction cost, and construction economy, has become an important technical problem that urgently needs to be solved.

[0007] It should be clarified here that the above description is intended to facilitate understanding of the overall background of the present invention, and should not be construed as an admission or implication in any way that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0008] This invention provides a prefabricated goaf-side retaining wall unit and wall structure to solve the shortcomings of traditional goaf-side retaining in the prior art, which cannot meet the support requirements of rapid advance working faces. It can realize the prefabrication and assembly of the support structure, high load-bearing capacity and coordination, rapid construction and cost optimization, and better match the support requirements of rapid advance working faces.

[0009] This invention provides a prefabricated wall unit for retaining space along a passageway, comprising: The outer shell, whose inner wall defines the casting cavity; A capping plate is disposed within the casting cavity and fixedly connected to the outer shell; along the longitudinal direction of the outer shell, the capping plate divides the casting cavity into a precast cavity and a capping cavity, with the end of the capping cavity away from the precast cavity open; the precast cavity is used to pour concrete during the precasting stage of the wall unit, and the capping cavity is used to pour high-strength concrete during the capping stage; A shear connector is disposed within the casting cavity and fixedly connected to the outer shell, for connecting the outer shell and the concrete within the casting cavity.

[0010] According to a prefabricated goaf retaining wall unit provided by the present invention, the shear connector is configured as a PBL connector; The PBL connectors extend longitudinally along the housing, and multiple PBL connectors are spaced apart and cover the inner wall of the housing.

[0011] According to the present invention, a prefabricated goaf retaining wall unit is provided, wherein the top plate is provided with a clearance notch for the PBL connector to pass through; And / or, The top plate is welded to the outer shell, and stiffening ribs are welded between the top plate and the outer shell.

[0012] According to the present invention, a prefabricated goaf retaining wall unit is provided, wherein the end of the outer shell away from the capping cavity is fixedly connected to a flange, and the flange is provided with a plurality of elongated holes, each of which is used to accommodate two or more bolts.

[0013] According to the present invention, a prefabricated goaf retaining wall unit is provided, wherein the outer shell is configured as a box-shaped structure with a rectangular cross-section, and the top plate is configured as a rectangular plate adapted to the shape of the outer shell.

[0014] According to the present invention, a prefabricated goaf retaining wall unit is provided, wherein the outer shell is configured as a column structure with an annular cross section, and the capping plate is configured as a circular plate adapted to the shape of the outer shell.

[0015] The present invention also provides a prefabricated sidewalk retaining wall structure, comprising multiple prefabricated sidewalk retaining wall units spliced ​​together in the longitudinal and transverse directions.

[0016] According to the present invention, a prefabricated wall structure for retaining passageways along the road is provided, wherein two laterally adjacent wall units are connected by clamps; the clamps include: Two clips are provided, each clip having a relatively bent hook end, and the two clips are configured to be able to move closer to or further away from each other; the outer shell is provided with slots for adapting the clips, and the two clips respectively engage with the slots on two laterally adjacent wall units; A locking structure, connected to the locking heads, is used to drive the two locking heads closer together to lock them into the slot.

[0017] According to a prefabricated goaf-retaining wall structure provided by the present invention, the locking structure includes: a screw rod and two threaded sleeves threadedly connected to the screw rod; The screw has two threaded segments with opposite thread directions, and the internal threads of the two threaded sleeves have the same thread direction and are respectively connected to the two threaded segments; or, the internal threads of the two threaded sleeves have opposite threads and are threadedly connected to the screw. When the screw rotates, the two threaded sleeves can move closer or further apart from each other, and the two clamps are respectively connected to the two threaded sleeves.

[0018] According to the present invention, a prefabricated wall structure for retaining space along the goaf is provided, wherein the outer periphery of the screw is provided with a screwing part with a polygonal cross section, and the screwing part is used to cooperate with a screwing tool.

[0019] The present invention also provides a prefabricated sidewalk retaining wall structure, comprising a plurality of the above-mentioned prefabricated sidewalk retaining wall units spliced ​​in the longitudinal direction.

[0020] The prefabricated gob-side retaining wall unit and wall structure provided by this invention, in actual construction, involves prefabricating wall units in a factory before constructing the wall structure. Concrete is poured into the prefabrication cavity of the outer shell and cured to the design strength. Then, high-strength concrete is poured into the capping cavity for sealing. After prefabrication, the wall units are transported underground for assembly. For longitudinal assembly, a special lifting device is used to fix the first wall unit at a designated position. The next wall unit is then hoisted and aligned with the already fixed wall unit before being lowered onto its top. Adjacent wall units are then fixed until the entire wall structure is completed. Finally, the tightness of the wall unit connections is checked, and a mine pressure monitoring system is activated to collect the support load of the wall structure, ensuring that the support load meets the mine pressure bearing requirements of the gob-side retaining system. Compared to related technologies, this prefabricated gob-side retaining wall unit has at least the following advantages: I. The shell-concrete composite structure of this wall unit provides high-rigidity external constraints through the shell and strengthens internal bonding through shear-resistant connectors. At the same time, the "capping plate + high-strength concrete" capping design evenly transfers the concentrated mining pressure of the roadway roof to the entire wall unit, avoiding stress concentration at the top of the wall structure due to local point contact, reducing shell buckling or concrete crushing problems. The synergistic force-bearing capacity between the various components in the wall unit is outstanding, and the load-bearing capacity far exceeds that of traditional flexible formwork concrete support. Moreover, it is prefabricated and cured in the factory, and has full load-bearing capacity upon installation. It can directly resist the dynamic pressure impact of rapidly advancing working faces, solving the problems of insufficient load-bearing capacity, poor synergistic workability, and strength improvement lagging behind the mining progress of traditional technologies.

[0021] Second, the wall unit adopts fully prefabricated assembly construction, with no wet work on site, significantly reducing the number of workers per shift (in accordance with the underground personnel limit regulations), and multiple wall units can be installed in a single shift. The roadway retention speed is precisely matched with the working face advancement needs, effectively solving the problems of low installation efficiency and high construction costs of traditional technologies.

[0022] Third, the concrete usage of this wall unit is only about half that of a flexible formwork concrete wall of the same specification. No additional material is required for the outer shell, and it eliminates the need for disposable templates, flexible membrane bags, and other consumables in traditional technologies. The total material cost per meter of tunnel is significantly reduced, effectively solving the problems of large material usage and poor economic efficiency of existing technologies.

[0023] Understandably, the specific materials, structural forms, and size specifications of each component in this wall unit can be selected and designed according to the actual application scenario. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the side-entry retaining wall unit provided in Embodiment 1 of the present invention.

[0026] Figure 2 This is a cross-sectional view of the wall unit along the passageway provided in Embodiment 1 of the present invention.

[0027] Figure 3 This is a schematic diagram of the structure of the shell of the wall unit for retaining space along the roadway provided in Embodiment 1 of the present invention.

[0028] Figure 4 This is a cross-sectional view of the shell of the wall unit for retaining space along the roadway provided in Embodiment 1 of the present invention.

[0029] Figure 5 This is a schematic diagram of the structure of the side-entry retaining wall unit provided in Embodiment 2 of the present invention.

[0030] Figure 6 This is a cross-sectional view of the wall unit along the passageway provided in Embodiment 2 of the present invention.

[0031] Figure 7 This is a schematic diagram of the structure of the shell of the wall unit for retaining space along the roadway provided in Embodiment 2 of the present invention.

[0032] Figure 8 This is a cross-sectional view of the shell of the wall unit for retaining space along the roadway provided in Embodiment 2 of the present invention.

[0033] Figure 9 This is a schematic diagram of a wall structure constructed using the wall unit provided in Embodiment 1 of the present invention.

[0034] Figure 10 This is a schematic diagram of the wall unit provided in Embodiment 1 of the present invention being connected in the horizontal direction.

[0035] Figure 11 This is a schematic diagram of the wall unit provided in Embodiment 1 of the present invention being connected in the horizontal and vertical directions.

[0036] Figure 12 This is a schematic diagram of the fixture provided in an embodiment of the present invention.

[0037] Figure 13 This is a schematic diagram of a wall structure constructed using the wall unit provided in Embodiment 2 of the present invention.

[0038] Figure 14 A schematic diagram of the longitudinal connection of the wall unit provided in Embodiment 2 of the present invention.

[0039] Figure label: 10. Wall unit; 11. Shell; 110. Casting cavity; 111. Precast cavity; 112. Capping cavity; 12. Capping plate; 121. Stiffening rib; 13. Shear connector; 14. First support body; 15. Second support body; 16. Flange; 161. Long hole; 17. Bolt; 18. Groove; 21. Clamp; 211. Clamp head; 212. Threaded rod; 213. Threaded sleeve; 214. Tightening part. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0041] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" or "linked" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances. The descriptions using terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the embodiments of the present invention.

[0042] To better understand the prefabricated goaf retaining wall unit and wall structure provided by this invention, we first introduce its application background. The goaf retaining wall-less mining technology can effectively recover coal pillar resources left over from traditional mining, improve the resource recovery rate, reduce the amount of roadway excavation, and alleviate the tension between mining and excavation. It has been widely used in mining scenarios of medium and thick coal seams and below in national-level coal bases such as Inner Mongolia and Shaanxi.

[0043] While current mainstream goaf retention technologies, such as flexible concrete walls, offer the advantage of simple support structures, they exhibit several unavoidable drawbacks when faced with the demands of rapid face advancement: First, they are poorly adapted to rapidly advancing faces, with traditional concrete strength development lagging behind mining progress, and their load-bearing capacity and collaborative workability being insufficient, making them unable to withstand dynamic pressure. Second, they suffer from low installation efficiency and high construction costs, relying heavily on manpower for on-site operations, frequently exceeding the minimum manpower requirement underground, and the retention speed failing to match the face advancement demands. Third, they consume large quantities of materials and are economically inefficient, with high consumption of concrete and disposable consumables, resulting in persistently high total material costs.

[0044] In view of the above problems, embodiments of the present invention provide a prefabricated wall unit and wall structure for roadway retention along the goaf, which can realize the prefabrication and assembly of the support structure, high load-bearing capacity and coordination, rapid construction and cost optimization, and better match the support requirements of rapidly advancing working faces.

[0045] The following is combined Figures 1 to 14 This invention describes the prefabricated side-entry retaining wall unit and wall structure.

[0046] Reference Figures 1 to 4 A prefabricated goaf-side retaining wall unit includes an outer shell 11, a capping plate 12, and a shear connector 13. The inner wall of the outer shell 11 defines a casting cavity 110. The capping plate 12 is disposed within the casting cavity 110 and fixedly connected to the outer shell 11. Longitudinally, the capping plate 12 divides the casting cavity 110 into a precast cavity 111 and a capping cavity 112. The end of the capping cavity 112 away from the precast cavity 111 is open. The precast cavity 111 is used to pour concrete during the prefabrication stage of the wall unit 10 to form a first support 14, and the capping cavity 112 is used to pour concrete during the capping stage to form a second support 15. The shear connector 13 is disposed within the casting cavity 110 and fixedly connected to the outer shell 11, and is used to connect the outer shell 11 and the concrete within the casting cavity 110.

[0047] In actual construction, before the wall structure is built, wall units 10 are prefabricated in the factory. Concrete is poured into the prefabrication cavity 111 of the outer shell 11 and cured to the design strength. Then, high-strength concrete is poured into the capping cavity 112 for capping. After the wall units 10 are prefabricated, they are transported underground for assembly. For longitudinal assembly, a special lifting device is used to fix the first wall unit 10 at a designated position. Then, the next wall unit 10 is hoisted and aligned with the fixed wall unit 10 before being lowered onto its top. Adjacent wall units 10 are then fixed until the entire wall structure is completed. Finally, the tightness of the wall unit 10 connections is checked, and the mine pressure monitoring system is activated to collect the support load of the wall structure to ensure that the support load of the wall structure meets the mine pressure bearing requirements of the goaf retention roadway. Compared with related technologies, this prefabricated goaf retention roadway wall unit 10 has at least the following advantages: 1. The outer shell 11 of the wall unit 10, a concrete composite structure, provides high-rigidity external constraints through the outer shell 11 and strengthens internal bonding through shear connectors 13. At the same time, the capping design of "capping plate 12 + high-strength concrete" evenly transfers the concentrated mining pressure of the roadway roof to the entire wall unit 10, avoiding stress concentration at the top of the wall structure due to local point contact, reducing buckling of the outer shell 11 or crushing of the concrete. The synergistic force-bearing capacity among the various components in the wall unit 10 is outstanding, and its load-bearing capacity far exceeds that of traditional flexible formwork concrete support. Moreover, it is prefabricated and cured in the factory, and has full load-bearing capacity upon installation. It can directly resist the dynamic pressure impact of the rapidly advancing working face, solving the problems of insufficient load-bearing capacity, poor synergistic workability, and strength improvement lagging behind the mining progress of traditional technologies.

[0048] Second, the wall unit 10 adopts fully prefabricated assembly construction, with no wet work on site, significantly reducing the number of workers per shift (in accordance with the underground personnel limit regulations), and multiple wall units 10 can be installed in a single shift. The roadway retention speed is precisely matched with the working face advancement needs, effectively solving the problems of low installation efficiency and high construction cost of traditional technology.

[0049] Third, the concrete usage of the wall unit 10 is only about half that of the flexible formwork concrete wall of the same specification. The outer shell 11 does not require additional usage, and it eliminates the need for disposable templates, flexible membrane bags and other consumables in traditional technologies. The total material cost per meter of tunnel is significantly reduced, effectively solving the problems of large material usage and poor economic efficiency in existing technologies.

[0050] It is understandable that the specific materials, structural forms, and size specifications of each component in the wall unit 10 can be selected and designed according to the actual application scenario.

[0051] Example 1 In this embodiment, the outer shell 11 is configured as a box-shaped structure with a rectangular cross-section, and the top plate 12 is configured as a rectangular plate that matches the shape of the outer shell 11. The wall unit 10 is a rectangular structure after prefabrication. When constructing the wall structure, multiple wall units 10 are spliced ​​longitudinally to match the height of the alleyway and connected laterally to form a continuous and sealed wall structure.

[0052] In one example of the present invention, the outer shell 11 is configured as a steel shell. Compared with other materials, the steel shell has higher tensile, shear, and compressive strength, providing stable and high-strength external constraints for the wall unit 10. Specifically, the outer shell 11 can be integrally formed, for example, by integral stamping, bending, or other processes, to ensure the structural integrity and rigidity of the outer shell 11; the outer shell 11 can also be welded together, for example, by assembling steel plates through welding. Welded outer shell 11 offers high processing flexibility, low processing cost, and is better suited to complex working conditions.

[0053] It is understandable that the two molding processes of the outer shell 11 can be selected according to the actual working conditions, and no specific restrictions are imposed here.

[0054] In one example of the present invention, at least the top end of the outer shell 11 along its longitudinal direction is set as an open opening. Of course, depending on actual needs, the bottom end of the outer shell 11 along its longitudinal direction can also be set as an open opening. The top plate 12 is configured as a steel plate, which is located in the casting cavity 110 of the outer shell 11 and is fixedly connected to the inner wall of the outer shell 11. The top plate 12 is relatively close to the top opening of the outer shell 11, so that the inner wall of the outer shell 11 and the bottom surface of the top plate 12 define the aforementioned precast cavity 111 with a larger volume, and the inner wall of the outer shell 11 and the upper surface of the top plate 12 define the aforementioned top cavity 112 with a smaller volume and an open opening.

[0055] With this configuration, when prefabricating the wall unit 10, concrete is first poured into the prefabricated cavity 111 of the outer shell 11 and cured to the design strength to form the first support 14. Then, high-strength concrete is poured into the capping cavity 112 to seal it, forming the second support 15. The arrangement of the capping cavity 112 can meet the support and sealing requirements of the tunnel roof through concrete pouring. When the top of the wall unit 10 is under pressure, the exposed part of the second support 15 is directly under pressure, thereby increasing the pressure-bearing area of ​​the wall unit 10, avoiding pressure concentration caused by local point contact, and also evenly transmitting the pressure to the entire wall unit 10 through the capping plate 12, effectively preventing the buckling of the outer shell 11 or the crushing of the concrete.

[0056] In some optional examples of the present invention, the top plate 12 and the outer shell 11 can be fixed by connecting components such as bolts, or by welding, or they can be integrally formed, depending on the actual needs.

[0057] In this embodiment, to reduce assembly difficulty and improve assembly efficiency and flexibility, the top plate 12 and the outer shell 11 are fixed by welding. In addition, stiffening ribs 121 can be welded to the side of the top plate 12 facing away from the top cavity 112 to enhance its rigidity, prevent it from buckling locally under the pressure of the top plate, and improve the uniformity of pressure transmission.

[0058] In one example of the present invention, the shear connector 13 is configured as a PBL connector, which extends longitudinally along the housing 11, and a plurality of PBL connectors are spaced apart and cover the inner wall of the housing 11.

[0059] In detail, the main body of the PBL connector is a steel plate with regular holes, which is fixed to the inner wall of the outer shell 11 by welding. Through its fixed connection with the inner wall of the outer shell 11 and its structural rigidity, the PBL connector can effectively constrain the local deformation of the outer shell 11 and prevent the outer shell 11 from buckling locally. In addition, the regular holes on the steel plate form an interlocking structure with the internal concrete, realizing a reliable connection between the outer shell 11 and the internal concrete, thereby limiting the relative slippage or separation of the outer shell 11 and the concrete during the stress process, and ensuring the coordinated stress performance of the overall structure.

[0060] Furthermore, the capping plate 12 is provided with a clearance notch for the PBL connector to pass through. This design serves two purposes: firstly, it avoids structural interference between the capping plate 12 and the PBL connector, ensuring the complete installation of the PBL connector and its full arrangement along the inner wall of the outer shell 11, thus guaranteeing its shear force transmission, buckling resistance, and steel-concrete connection functions; secondly, the fit between the clearance notch and the PBL connector reduces the installation gap between them, lowering the risk of structural stress concentration, and providing favorable conditions for the subsequent connection and fixation of the capping plate 12 with the outer shell 11 and the PBL connector, further improving the overall structural sealing and mechanical integrity, and ensuring the stability of the outer shell 11 and the concrete under the same load.

[0061] In one example of the present invention, a flange 16 is fixedly connected to the end of the outer shell 11 away from the capping cavity 112. With this configuration, when assembling the wall unit 10, two longitudinally adjacent wall units 10 can be connected by the flange 16 and the longitudinal connection of the two wall units 10 can be completed by inserting bolts 17.

[0062] Furthermore, the flange 16 is provided with multiple elongated holes 161, each of which is used to accommodate two or more bolts 17. This arrangement provides adjustment space through the elongated holes 161. Even if there are slight coaxiality deviations or hole misalignments between the flanges 16 of the upper and lower wall units 10, quick alignment can be achieved by fine-tuning the position of the bolts 17 within the elongated holes 161. This eliminates the need for secondary processing or forced correction of the flange 16 hole positions, improving assembly tolerance, reducing on-site assembly difficulty, and increasing construction efficiency. In addition, each elongated hole 161 can accommodate two or more bolts 17, ensuring uniform stress distribution on the flange 16 mating surfaces and avoiding localized stress concentration. Combined with the fitting clearance between the elongated holes 161 and the bolts 17, it can offset minor relative displacements when the upper and lower segments are under stress, improving the stability and reliability of the connection.

[0063] Furthermore, the outer casing 11 has slots 18 on both sides of its horizontal direction. It is understood that the rectangular wall unit 10 needs to be spliced ​​both longitudinally and laterally. When splicing the wall units 10, two longitudinally adjacent walls can be connected using the aforementioned flanges 16 and bolts 17, while two laterally adjacent wall units 10 can be connected using clamps 21 that mate with the slots 18. This eliminates the need for on-site welding, reducing on-site work and personnel input. The specific structure of the clamps 21 will be described in detail below and will not be introduced here.

[0064] Example 2 Reference Figures 5 to 8 In this embodiment, the outer shell 11 is configured as a column structure with an annular cross section, and the top plate 12 is configured as a circular plate that matches the shape of the outer shell 11. The wall unit 10 is prefabricated into a column structure. When constructing the wall structure, two or more wall units 10 are spliced ​​together in the longitudinal direction to match the height of the alleyway and placed in the transverse direction to form a wall structure.

[0065] It should be noted that when the shape of the outer shell 11 changes, only the shape of the other components of the wall unit 10 needs to be adjusted accordingly. Therefore, the structure of the other components of the wall unit 10 in this embodiment can refer to Embodiment 1, and will not be described again here.

[0066] The prefabricated goaf retaining wall structure provided by the present invention will be described below. The prefabricated goaf retaining wall structure described below can be referred to in correspondence with the prefabricated goaf retaining wall unit 10 described above.

[0067] In one example of the present invention, reference is made to Figures 9 to 12 A prefabricated gob-side retaining wall structure includes multiple prefabricated gob-side retaining wall units 10; the outer shell 11 of the wall unit 10 is configured as a box-shaped structure with a rectangular cross section, and the multiple wall units 10 are spliced ​​in the longitudinal and transverse directions and the outer shell 11 of adjacent wall units 10 are fixedly connected.

[0068] It is understood that, in the longitudinal direction, two adjacent wall units 10 can be connected by the flange 16 and bolt 17 described in the above embodiments.

[0069] To facilitate the horizontal connection of adjacent wall units 10, in one example of the present invention, two horizontally adjacent wall units 10 are connected by a clamp 21; the clamp 21 includes a clamp head 211 and a locking structure; wherein, the clamp head 211 is provided with two clamp heads, and the two clamp heads 211 are provided with relatively bent hook ends, the two clamp heads 211 are configured to be able to approach or move away from each other, the outer shell 11 is provided with a slot 18 adapted to the clamp head 211, and the two clamp heads 211 respectively engage with the slots 18 on the two horizontally adjacent wall units 10; the locking structure is connected to the clamp head 211 and is used to drive the two clamp heads 211 to approach each other so as to lock them with the slots 18.

[0070] With this configuration, when assembling wall units 10, the hook ends of the two clips 211 of the clamp 21 are respectively hooked into the slots 18 of two horizontally adjacent wall units 10. Then, the locking mechanism drives the two clips 211 to move closer to each other, and the hook ends lock with the slots 18, thus achieving the horizontal connection and fixation of the two wall units 10. In this process, there is no need for complex hole processing or welding operations on site. The wall units 10 can be quickly connected simply by using the pre-set slots 18 and clamps 21, simplifying the construction process for horizontal connection and reducing the difficulty of on-site operation.

[0071] It is understandable that the specific structure of the locking mechanism can be designed according to actual needs, as long as it can drive the two locking heads 211 to move closer to each other and lock into the slot 18.

[0072] As a feasible solution in this embodiment, the locking structure includes a screw 212 and two threaded sleeves 213 threadedly connected to the screw 212. The screw 212 has two threaded segments with opposite thread directions, and the internal threads of the two threaded sleeves 213 have the same direction and are respectively connected to the two threaded segments. The two locking heads 211 are respectively connected to the two threaded sleeves 213. With this configuration, when the screw 212 is turned, the two threaded sleeves 213 can be driven to move synchronously, causing them to move closer or further apart, thereby achieving the locking of the locking heads 211 with the slot 18.

[0073] As another feasible solution in this embodiment, the locking structure includes a screw 212 and two threaded sleeves 213 threadedly connected to the screw 212; the internal threads of the two threaded sleeves 213 have opposite directions and are threadedly connected to the screw 212; the two locking heads 211 are respectively connected to the two threaded sleeves 213. With this configuration, when the screw 212 is turned, the two threaded sleeves 213 can also be driven to move closer or further apart, thereby locking the locking heads 211 with the slot 18.

[0074] Furthermore, the outer periphery of the screw 212 is provided with a screwing part 214 with a polygonal cross-section (such as a regular square or a regular hexagon). The screwing part 214 is used to cooperate with a screwing tool (such as a wrench). With this configuration, after the two clamps 211 of the clamp 21 are initially inserted into the slot 18, the worker only needs to use a wrench to clamp the screw 212 to drive the two threaded sleeves 213 to move relative to each other, so that the clamp is locked with the slot 18, which helps to further improve the convenience of construction.

[0075] Furthermore, since the slot 18 penetrates the shell wall of the outer shell 11, in order to prevent the clamp 211 from crushing the concrete in the pouring cavity 110, fasteners can be pre-connected in the pouring cavity 110. The shape of the fasteners is adapted to the shape of the clamp 211. After the concrete is poured, the fasteners are embedded in the concrete. When connected, the clamp 211 engages with the fasteners, thereby reducing the problem of the concrete being crushed or cracked and ensuring the structural integrity of the concrete in the pouring cavity 110.

[0076] Of course, the above are just examples; other types of locking structures can also be applied, and they will not be listed one by one here.

[0077] In another example of the invention, reference is made to Figure 13 and Figure 14 A prefabricated gob-side retaining wall structure includes multiple prefabricated gob-side retaining wall units 10; the outer shell 11 of the wall unit 10 is configured as a column structure with an annular cross section, and the multiple wall units 10 are spliced ​​in the longitudinal direction and arranged in the transverse direction.

[0078] It is understood that, in the longitudinal direction, two adjacent wall units 10 can be connected by the flange 16 and bolt 17 described in the above embodiments.

[0079] It is understood that, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples.

[0080] The prefabricated goaf-side retaining wall unit 10 and wall structure provided in this embodiment of the invention have at least the following advantages: 1. The outer shell 11 of the wall unit 10, a concrete composite structure, provides high-rigidity external constraints through the outer shell 11 and strengthens internal bonding through shear connectors 13. At the same time, the capping design of "capping plate 12 + high-strength concrete" evenly transfers the concentrated mining pressure of the roadway roof to the entire wall unit 10, avoiding stress concentration at the top of the wall structure due to local point contact, reducing buckling of the outer shell 11 or crushing of the concrete. The synergistic force-bearing capacity among the various components in the wall unit 10 is outstanding, and its load-bearing capacity far exceeds that of traditional flexible formwork concrete support. Moreover, it is prefabricated and cured in the factory, and has full load-bearing capacity upon installation. It can directly resist the dynamic pressure impact of the rapidly advancing working face, solving the problems of insufficient load-bearing capacity, poor synergistic workability, and strength improvement lagging behind the mining progress of traditional technologies.

[0081] Second, the wall unit 10 adopts fully prefabricated assembly construction, with no wet work on site, significantly reducing the number of workers per shift (in accordance with the underground personnel limit regulations), and multiple wall units 10 can be installed in a single shift. The roadway retention speed is precisely matched with the working face advancement needs, effectively solving the problems of low installation efficiency and high construction cost of traditional technology.

[0082] Third, the concrete usage of the wall unit 10 is only about half that of the flexible formwork concrete wall of the same specification. The outer shell 11 does not require additional usage, and it eliminates the need for disposable templates, flexible membrane bags and other consumables in traditional technologies. The total material cost per meter of tunnel is significantly reduced, effectively solving the problems of large material usage and poor economic efficiency in existing technologies.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A prefabricated wall unit for retaining space along a roadway, characterized in that, include: The outer shell (11) has an inner wall that defines the casting cavity (110). A capping plate (12) is disposed within the casting cavity (110) and fixedly connected to the outer shell (11); in the longitudinal direction of the outer shell (11), the capping plate (12) divides the casting cavity (110) into a precast cavity (111) and a capping cavity (112), and the end of the capping cavity (112) away from the precast cavity (111) is open; the precast cavity (111) is used to pour concrete during the precasting stage of the wall unit (10), and the capping cavity (112) is used to pour high-strength concrete during the capping stage; Shear connector (13) is disposed in the pouring cavity (110) and fixedly connected to the outer shell (11) for connecting the outer shell (11) and the concrete in the pouring cavity (110).

2. The prefabricated goaf-side retaining wall unit according to claim 1, characterized in that, The shear connector (13) is configured as a PBL connector; The PBL connectors extend longitudinally along the outer shell (11), and multiple PBL connectors are spaced apart and cover the inner wall of the outer shell (11).

3. The prefabricated goaf-side retaining wall unit according to claim 2, characterized in that, The top plate (12) is provided with a clearance notch for the PBL connector to pass through; And / or, The top plate (12) is welded to the outer shell (11), and a stiffening rib (121) is welded between the top plate (12) and the outer shell (11).

4. The prefabricated goaf-side retaining wall unit according to claim 1, characterized in that, A flange (16) is fixedly connected to the end of the outer shell (11) away from the capping cavity (112). The flange (16) is provided with a plurality of elongated holes (161), each of which is used to accommodate two or more bolts (17).

5. The prefabricated goaf-side retaining wall unit according to any one of claims 1 to 4, characterized in that, The outer shell (11) is configured as a box-shaped structure with a rectangular cross-section, and the top plate (12) is configured as a rectangular plate adapted to the shape of the outer shell (11).

6. The prefabricated goaf-side retaining wall unit according to any one of claims 1 to 4, characterized in that, The outer shell (11) is configured as a cylindrical structure with an annular cross-section, and the top plate (12) is configured as a circular plate adapted to the shape of the outer shell (11).

7. A prefabricated wall structure for retaining space along a roadway, characterized in that, Includes multiple prefabricated lane-keeping wall units (10) as described in claim 5, spliced ​​together in both longitudinal and transverse directions.

8. The prefabricated wall structure for retaining passageways along the road according to claim 7, characterized in that, Two horizontally adjacent wall units (10) are connected by a clamp (21); the clamp (21) includes: Two clips (211) are provided with oppositely bent hook ends, and the two clips (211) are configured to be able to approach or move away from each other; the outer shell (11) is provided with slots (18) adapted to the clips (211), and the two clips (211) respectively engage with the slots (18) on two laterally adjacent wall units (10); A locking structure, connected to the locking head (211), is used to drive the two locking heads (211) to come close to each other so as to lock them into the slot (18).

9. The prefabricated wall structure for retaining passageways along the roadway according to claim 8, characterized in that, The locking structure includes: a screw (212) and two threaded sleeves (213) threadedly connected to the screw (212); The screw (212) has two threaded segments with opposite thread directions. The internal threads of the two threaded sleeves (213) have the same direction and are respectively connected to the two threaded segments; or, the internal threads of the two threaded sleeves (213) have opposite directions and are threadedly connected to the screw (212). When the screw (212) rotates, the two threaded sleeves (213) can move closer or further apart from each other, and the two clamps (211) are respectively connected to the two threaded sleeves (213).

10. A prefabricated wall structure for retaining space along a roadway, characterized in that, It includes multiple prefabricated lane-keeping wall units (10) as described in claim 6, which are spliced ​​together in the longitudinal direction.

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